Chronic kidney disease (CKD) and impaired renal function have been implicated in venous thromboembolism (VTE), but their causal relationships remain uncertain. This study employs Mendelian randomization (MR) to elucidate the potential bidirectional causal effects between CKD, renal function biomarkers, and VTE.

We collated datasets from genome-wide association studies conducted among European individuals to perform MR analyses. The primary method utilized was the random-effect inverse variance-weighted (IVW) approach, with MR-Egger and the weighted median approaches employed as supplemental techniques. Several sensitivity studies were performed to assess the findings' robustness.

We identified a link between elevated serum creatinine levels and both VTE (OR: 1.14, 95% CI: 1.05-1.24, p = 0.001) and PE (OR: 1.20, 95% CI: 1.08-1.33, p = 0.001). After outlier removal and Bonferroni correction, the Cr-VTE association lost significance (p = 0.005). A suggestive causal relationship was found between eGFR and VTE (OR: 0.38, 95% CI: 0.20-0.73, p = 0.004), DVT (OR: 0.37, 95% CI: 0.16-0.87, p = 0.022), and PE (OR: 0.29, 95% CI: 0.12-0.66, p = 0.004). No causal effects of CKD or BUN on VTE or its subtypes were observed. Reverse causality inferences did not reveal any meaningful results.

This MR analysis provides evidence that elevated serum creatinine is associated with a higher risk of VTE and PE, while reduced eGFR may be a potential risk factor for VTE and its subtypes. These findings highlight the need for proactive monitoring and preventive strategies in individuals with impaired renal function. Further studies are warranted to confirm these associations and explore underlying mechanisms.

Massive pulmonary embolism (PE) is a disease with high mortality, therefore early diagnosis and treatment is essential to save lives. In the absence of contraindications, patients with massive PE (high risk) should be treated immediately with full-dose intravenous systemic thrombolysis. The subset of patients for whom systemic thrombolysis is not successful and who continue to present with haemodynamic compromise or those with contraindications may be candidates for various catheter-directed or surgical therapies. The decision algorithm in intermediate-high/submassive risk patients is complex and must be employed by a multidisciplinary team and success may depend on the experience of the medical specialists involved.

Pulmonary perfusion imaging is a key lung health indicator with clinical utility as a diagnostic and treatment planning tool. However, current nuclear medicine modalities face challenges like low spatial resolution and long acquisition times which limit clinical utility to non-emergency settings and often placing extra financial burden on the patient. This study introduces a novel deep learning approach to predict perfusion imaging from non-contrast inhale and exhale computed tomography scans (IE-CT).

We developed a U-Net Transformer architecture modified for Siamese IE-CT inputs, integrating insights from physical models and utilizing a self-supervised learning strategy tailored for lung function prediction. We aggregated 523 IE-CT images from nine different 4DCT imaging datasets for self-supervised training, aiming to learn a low-dimensional IE-CT feature space by reconstructing image volumes from random data augmentations. Supervised training for perfusion prediction used this feature space and transfer learning on a cohort of 44 patients who had both IE-CT and single-photon emission CT (SPECT/CT) perfusion scans.

Testing with random bootstrapping, we estimated the mean and standard deviation of the spatial Spearman correlation between our predictions and the ground truth (SPECT perfusion) to be 0.742 ± 0.037, with a mean median correlation of 0.792 ± 0.036. These results represent a new state-of-the-art accuracy for predicting perfusion imaging from non-contrast CT.

Our approach combines low-dimensional feature representations of both inhale and exhale images into a deep learning model, aligning with previous physical modeling methods for characterizing perfusion from IE-CT. This likely contributes to the high spatial correlation with ground truth. With further development, our method could provide faster and more accurate lung function imaging, potentially expanding its clinical applications beyond what is currently possible with nuclear medicine.

The unprimed right ventricle is exquisitely sensitive to acute elevations in afterload. High pulmonary vascular tone incurred with acute pulmonary embolism has the potential to induce obstructive shock and circulatory collapse. While emergent pulmonary reperfusion is essential in severe circumstances, an important subset of pulmonary embolism patients may exhibit a less extreme presentation posing a management dilemma. As intensive care therapies have the potential to both salvage and harm the failing right ventricle, a keen understanding of the pathophysiology is requisite in the care of the contemporary patient with hemodynamically significant pulmonary embolism. Here, we review right ventricular pathophysiology, an approach to risk stratification, and offer guidance on the medical and mechanical supportive and therapeutic strategies for the critically ill patient with acute pulmonary embolism.

Up to 50% of patients with pulmonary embolism (PE) experience hemodynamic instability and approximately 70% of patients who die of PE experience an accelerated cascade of symptoms within the first hours of onset of symptoms, thus necessitating rapid evaluation and intervention. Venoarterial extracorporeal membrane oxygenation and other ventricular assist devices, depending on the hemodynamic derangements present, may be used to stabilize patients with massive PE refractory to initial therapies or with contraindications to other interventions. Given the abnormalities in both pulmonary circulation and gas exchange caused by massive PE, venoarterial extracorporeal membrane oxygenation may be considered the preferred form of mechanical circulatory support for most patients. Venoarterial extracorporeal membrane oxygenation unloads the right ventricle and improves oxygenation, which may not only help buy time until definitive treatment but may also reduce myocardial ischemia and myocardial dysfunction. This review summarizes the available clinical data on the use of mechanical circulatory support, especially venoarterial extracorporeal membrane oxygenation, in the treatment of patients with massive PE. Furthermore, this review also provides practical guidance on the implementation of this strategy in clinical practice.

•Massive pulmonary embolism (PE) during pregnancy or the postpartum period is a rare but potentially lethal event.•Physiological changes in the coagulation system during pregnancy and puerperium would lead to a hypercoagulable state.•Diagnosis of PE in pregnancy remains a challenge due to physiological changes in pregnancy. There are no validated scoring systems for assessing pregnant/postpartum women with suspected PE. Massive PE should be suspected in all cases with haemodynamic instability in pregnancy.•The Management of massive pulmonary embolism should be timely and aggressive. Thrombolysis for massive PE during pregnancy and the postpartum period has shown to be associated with high maternal and fetal survival (94% and 88%). But other therapeutic options such as (catheter [or surgical] thrombectomy, ECMO) should be considered in the postpartum period, given the high risk of major bleeding with thrombolysis.•Thrombolysis remains the most-used and reasonably successful modality of treatment in pregnancy but should be avoided in the postpartum period as it can cause life-threatening haemorrhage. During the post-partum period, thrombectomy is the treatment of choice.

•To understand the pathophysiology of massive PE.•To appreciate the treatment options in pregnancy and postpartum period and their pros and cons.•To understand the need for further work in this area especially in creating a validated algorithm for diagnosing PE in pregnancy and postpartum period.

The estimated incidence of pulmonary embolism (PE) is around 60-70 cases per 100,000 people annually. The overall mortality rate for massive PE is substantial, ranging from 18% to 65%. We can utilise changes in lung perfusion to stratify patients with PE acutely based on risk, highlighting its diagnostic and prognostic value.

To calculate the whole-lung perfused blood volume (PBV) and right-to-left ventricular diameter ratio from dual-energy computed tomography thorax in patients with acute PE and find its association with 28-day all-cause mortality.

This was a prospective diagnostic accuracy study at the Jawaharlal Institute of Post-Graduate Medical Education and Research. We included suspected acute PE patients. A dual-energy chest CT was performed on all these patients, and iodine maps were generated using the Syngo dual-energy workstation. Whole-lung PBVs were then calculated. Patients were followed up for 28 days, and all-cause mortality data were collected. The prognostic accuracy of PBVs in predicting mortality among acute PE patients was analysed using the ROC curve using SPSS version 19.0.

The area under the curve (AUC) was 0.696, indicating a moderate discriminatory power in distinguishing between patients who experienced mortality and those who did not. An empirical cut-off value of 0.945 corresponds to a sensitivity of 63.2% and a specificity of 67.6%.

The prognostic accuracy of total perfused lung volume/total lung volume revealed a moderate discriminatory power, indicating 70% accuracy in predicting 28-day mortality based on standardised total PBVs.

Pulmonary embolism (PE) is a critical condition characterized by the obstruction of pulmonary arteries by thrombi, which significantly contributes to morbidity and mortality globally. Although prolonged elevated heart rate (peHR) is recognized as a risk factor for adverse outcomes in critically ill patients, its specific impact on severe PE has remained unexplored.

This retrospective cohort study analyzed data from the Medical Information Mart for Intensive Care (MIMIC)-IV database. Patients diagnosed with PE were included in the study. peHR was defined as heart rates exceeding 100 beats per minute on at least 11 occasions within any 12-h interval. Cox proportional hazards regression models were used to evaluate the impact of peHR on 30-day and 90-day mortality rates, adjusting for a broad range of demographic and clinical variables.

A total of 1248 patients were included in this study, of whom 540 exhibited peHR. These patients experienced significantly longer hospital and intensive care unit (ICU) stays, as well as higher mortality rates at both 30 days (25.93 % vs. 14.97 %, P < 0.001) and 90 days (33.89 % vs. 22.74 %, P < 0.001) compared to patients without peHR. Multivariate Cox regression analysis confirmed peHR as an independent predictor of increased mortality at 30 days (HR 1.56, 95 % CI 1.19-2.07; P = 0.0014) and 90 days (HR 1.66, 95 % CI 1.32-2.10; P < 0.001).

peHR significantly worsens outcomes in severe PE patients, underscoring the need for stringent heart rate monitoring and management. These findings advocate for integrating heart rate control within management strategies for severe PE, potentially improving survival outcomes.

Acute pulmonary embolism (PE) is a common disease encountered by pulmonologists, cardiologists, and critical care physicians throughout the world. For patients with high-risk acute PE (defined by systemic hypotension) and intermediate high-risk acute PE (defined by the absence of systemic hypotension, but the presence of numerous other concerning clinical and imaging features), intensive care often is necessary. Initial management strategies should focus on optimization of right ventricle (RV) function while decisions about advanced interventions are being considered.

We reviewed the existing literature of various vasoactive agents, IV fluids and diuretics, and pulmonary vasodilators in both animal models and human trials of acute PE. We also reviewed the potential complications of endotracheal intubation and positive pressure ventilation in acute PE. Finally, we reviewed the data of venoarterial extracorporeal membrane oxygenation use in acute PE. The above interventions are discussed in the context of the underlying pathophysiologic features of acute RV failure in acute PE with corresponding illustrations.

Norepinephrine is a reasonable first choice for hemodynamic support with vasopressin as an adjunct. IV loop diuretics may be useful if evidence of RV dysfunction or volume overload is present. Fluids should be given only if concern exists for hypovolemia and absence of RV dilatation. Supplemental oxygen administration should be considered even without hypoxemia. Positive pressure ventilation should be avoided if possible. Venoarterial extracorporeal membrane oxygenation cannulation should be implemented early if ongoing deterioration occurs despite these interventions.

Pulmonary embolism (PE) remains a significant cause of mortality requiring prompt diagnosis and risk stratification. This review focuses on the role of computed tomography (CT) in the risk stratification of acute PE, highlighting its impact on patient management. We will explore basic pathophysiology of pulmonary embolism (PE) and review current guidelines, which will help radiologists interpret images within a broader clinical context. This review covers key CT findings which can be used for risk stratification including indicators of right ventricular (RV) dysfunction, clot burden, clot location and left atrial volume. We will discuss the measurement of RV/LV diameter ratio as a key indicator of RV dysfunction and its limitations and challenges within various patient populations. While these parameters should be included in a radiologist's report, their predictive value for mortality depends on the patient's existing cardiopulmonary reserve and should not be interpreted in isolation.

Acute pulmonary embolism (PE) mortality is linked to abrupt rises in pulmonary artery (PA) pressure due to mechanical obstruction and pulmonary vasoconstriction, leading to right ventricular (RV) dilation, increased RV wall tension and oxygen demand, but compromised right coronary artery oxygen supply. Oxygen is a known pulmonary vasodilator, and in preclinical animal models of PE, supplemental oxygen reduces PA pressures and improves RV function. However, the mechanisms driving these interactions, especially in humans, remain poorly understood. The overall objective of the supplemental oxygen in pulmonary embolism (SO-PE) study is to investigate the mechanisms of supplemental oxygen in patients with acute PE.

This randomised, double-blind, cross-over trial at Massachusetts General Hospital will include adult patients with acute PE and evidence of RV dysfunction but without hypoxaemia (SaO2 ≥90% on room air). We will enrol 80 patients, each serving as their own control, with 40 randomised to start on supplemental oxygen, and 40 randomised to start on room air. Over 180 min, patients will alternate between supplemental oxygen delivered by non-rebreather mask (60% FiO2) and room air (21% FiO2). The primary outcome will be the difference in pulmonary artery systolic pressure with and without oxygen. Secondary outcomes include additional echocardiographic measures, metabolomic profiles, vital signs and dyspnoea scores. Echocardiographic data will be compared by a paired t-test or Wilcoxon signed-rank test. For metabolomic analyses, we will perform multivariable mixed effects logistic regression models and calculate false discovery rate (q-value ≤0.05) to account for multiple comparisons. Data will be collected in compliance with National Institutes of Health and National Heart Lung and Blood Institute (NHLBI) policies for data and safety monitoring.

The SO-PE study is funded by the NHLBI and has been approved by the Institutional Review Board of Mass General Brigham (no. 2023P000252). The study will comply with the Helsinki Declaration on medical research involving human subjects. All participants will provide prospective, written informed consent.

NCT05891886.

Data regarding the mortality trends in pulmonary embolism (PE)-related mortality in patients with concomitant pulmonary hypertension (PH) are lacking. We assessed the trends in PE-related mortality in patients with concomitant PH in the United States (US) over the past 2 decades and during the first year of the COVID-19 pandemic using data from the Centers for Disease Control and Prevention's (CDC) Wide-ranging ONline Data for Epidemiologic Research (WONDER) dataset.

Mortality data were retrieved from the publicly available CDC WONDER mortality dataset from 2003 to 2020. Age-adjusted mortality rates (AAMRs), per 100,000 population, were assessed using Joinpoint regression modelling and expressed as estimated average annual percentage change (AAPC) with relative 95% CIs and stratified by urbanicity, sex, age, and race/ethnicity.

Over the study period, the AAMR for PE/PH-related mortality linearly increased (AAPC: +4.3% [95% CI: 3.7 to 4.9], p < 0.001) without sex differences. The AAMR increase was more pronounced in White individuals (AAPC: +4.8% [95% CI: 4.1 to 5.5], p < 0.001) and in subjects living in rural areas (AAPC: +5.1% [95% CI: 3.8 to 6.4], p < 0.001) compared to those living in urban areas. During the first year of the COVID-19 pandemic there was a significant excess in PE/PH-related mortality among women, older than 65 years and living in rural areas.

The rate of PE/PH-related mortality in the US is increasing. Although the early diagnosis of PH in patients with acute PE has become easier with improved diagnostic modalities, the mortality rate of these patients remains high.

Massive pulmonary embolism (MPE) carries significant 30-day mortality risk, and a change in societal guidelines has promoted the increasing use of extracorporeal membrane oxygenation (ECMO) in the immediate management of MPE-associated cardiovascular shock. This narrative review examines the current status of ECMO in MPE.

A literature review was performed from 1982 to 2022 searching for the terms "Pulmonary embolism" and "ECMO," and the search was refined by examining those publications that covered MPE.

In the patient with MPE, veno-arterial ECMO is now recommended as a bridge to interventional therapy. It can reliably decrease right ventricular overload, improve RV function, and allow hemodynamic stability and restoration of tissue oxygenation. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Applying ECMO is also associated with substantial multisystem morbidity due to systemic inflammatory response, bleeding with coagulopathy, hemorrhagic stroke, renal dysfunction, and acute limb ischemia, which must be factored into the outcomes.

The application of ECMO in MPE should be combined with an aggressive interventional pulmonary interventional program and should strictly adhere to the current selection criteria.

Acute pulmonary embolism (PE) may manifest with mild nonspecific symptoms or progress to a more severe hemodynamic collapse and sudden cardiac arrest. A substantial thrombotic burden can precipitate sudden right ventricular strain and failure. Traditionally, systemic thrombolytics have been employed in such scenarios; however, patients often present with contraindications, or these interventions may prove ineffective. Outcomes for this medically complex patient population are unfavorable, necessitating a compelling argument for advanced therapeutic modalities or alternative approaches. Moreover, patients frequently experience complications beyond hemodynamic instability, such as profound hypoxia and multiorgan failure, necessitating assertive early interventions to avert catastrophic consequences. The existing data on the utilization of mechanical circulatory support (MCS) devices are not exhaustive. Various options for percutaneous MCS devices exist, each possessing distinct advantages and disadvantages. There is an imminent imperative to develop a tailored approach for this high-risk patient cohort to enhance their overall outcomes.

Right ventricular (RV) systolic dysfunction has been identified as a prognostic marker for adverse clinical events in patients presenting with acute pulmonary embolism (PE). However, challenges exist in identifying RV dysfunction using conventional echocardiography techniques. Strain echocardiography is an evolving imaging modality which measures myocardial deformation and can be used as an objective index of RV systolic function. This study evaluated RV Global Longitudinal Strain (RVGLS) in patients with intermediate risk PE as a parameter of RV dysfunction, and compared to traditional echocardiographic and CT parameters evaluating short-term mortality.

Retrospective single center cohort study of 251 patients with intermediate-risk PE between 2010 and 2018. The primary outcome was all-cause mortality at 30 days. Statistical analysis evaluated each parameter comparing survivors versus non-survivors at 30 days. Receiver operating characteristic (ROC) curves and Kaplan-Meier curves were used for comparison of the two cohorts.

Altogether 251 patients were evaluated. Overall mortality rate was 12.4%. Utilizing an ROC curve, an absolute cutoff value of 17.7 for RVGLS demonstrated a sensitivity of 93% and specificity of 70% for observed 30-day mortality. Individuals with an RVGLS ≤17.7 had a 25 times higher mortality rate than those with RVGLS above 17.7 (HR 25.24, 95% CI = 6.0-106.4, p < .001). Area under the curve was (.855), RVGLS outperformed traditional echocardiographic parameters, CT findings, and cardiac biomarkers on univariable and multivariable analysis.

Reduced RVGLS values on initial echocardiographic assessment of patients with intermediate-risk PE identified patients at higher risk for mortality at 30 days.

Venous thromboembolism (VTE), comprising deep venous thrombosis (DVT) and pulmonary embolism (PE), is a prevalent cardiovascular condition, ranking third globally after myocardial infarction and stroke. The risk of VTE rises with age, posing a growing concern in aging populations. Acute PE, with its high morbidity and mortality, emphasizes the need for early diagnosis and intervention. This review explores prognostic factors for acute PE, categorizing it into low-risk, intermediate-risk, and high-risk based on hemodynamic stability and right ventricular strain. Timely classification is crucial for triage and treatment decisions. In the contemporary landscape, low-risk PE patients are often treated with Direct Oral Anticoagulants (DOACS) and rapidly discharged for outpatient follow-up. Intermediate- and high-risk patients may require advanced therapies, such as systemic thrombolysis, catheter-directed thrombolysis, mechanical thrombectomy, and IVC filter placement. The latter, particularly IVC filters, has witnessed increased usage, with evolving types like retrievable and convertible filters. However, concerns arise regarding complications and the need for timely retrieval. This review delves into the role of IVC filters in acute PE management, addressing their indications, types, complications, and retrieval considerations. The ongoing debate surrounding IVC filter use, especially in patients with less conventional indications, reflects the need for further research and data. Despite complications, recent studies suggest that clinically significant issues are rare, sparking discussions on the appropriate and safe utilization of IVC filters in select PE cases. The review concludes by highlighting current trends, gaps in knowledge, and potential avenues for advancing the role of IVC filters in future acute PE management.

The potentially fatal consequences of pulmonary embolism emphasize the need for more effective diagnostic methods. The Qanadli obstruction index has been described as a convenient tool for risk stratification to determine and quantify the degree of obstruction. This study aimed to assess the correlations between the Qanadli index with clinical and paraclinical findings (D-dimer, troponin, and echocardiographic findings) in patients with pulmonary embolism.

A total of 102 patients with pulmonary embolism underwent echocardiography and CT pulmonary angiography at a single tertiary referral center between 2019 and 2020. The clinical and paraclinical findings, pulmonary arterial obstruction index, atrial measurements, right and left ventricle size and function, tricuspid annular plane systolic excursion, pulmonary artery pressure, and pulmonary hypertension (PH) were analyzed. Vital signs were recorded and assessed. The Qanadli index score was measured, and graded risk stratification was measured based on the quantified index score.

The total mean Qanadli index was 28.75 ± 23.75, and there was no significant relationship between the Qanadli index and gender. Patients' most common clinical findings were exertional dyspnea (84.3%; n = 86) and chest pain (71.7%; n = 73). There were significant correlations between the Qanadli index and pulse rate (PR), troponin, D-dimer levels, and PH. Four patients died during the study, including one from a cardiac condition and three with non-cardiac conditions.

It is possible to determine the severity, prognosis, and appropriate treatment by the Qanadli index based on strong correlations with PR, troponin, D-dimer levels, and PH.

Surgical pulmonary embolectomy is rarely used for the treatment of massive acute pulmonary embolism. The aim of this study was to assess the incidence and outcomes of this operation by undertaking a retrospective analysis of a large national registry in the UK.

All acute pulmonary embolectomies performed between 1996 and 2018 were captured in the National Institute of Cardiovascular Outcomes Research central database. Trends in the number of operations performed during this interval and reported in-hospital outcomes were analysed retrospectively. Multivariable logistic regression was used to identify independent risk factors for in-hospital death.

All 256 patients treated surgically for acute pulmonary embolism during the study interval were included in the analysis. Median age at presentation was 54 years, 55.9% of the patients were men, 48.0% had class IV heart failure symptoms, and 37.5% had preoperative cardiogenic shock. The median duration of bypass was 73 min, and median cross-clamp time was 19 min. Cardioplegic arrest was used in 53.1% of patients. The median duration of hospital stay was 11 days. The in-hospital mortality rate was 25%, postoperative stroke occurred in 5.4%, postoperative dialysis was required in 16%, and the reoperation rate for bleeding was 7.5%. Risk-adjusted multivariable analysis revealed cardiogenic shock (OR 2.54, 95% c.i. 1.05 to 6.21; P = 0.038), preoperative ventilation (OR 5.85, 2.22 to 16.35; P < 0.001), and duration of cardiopulmonary bypass exceeding 89 min (OR 7.82, 3.25 to 20.42; P < 0.001) as significant independent risk factors for in-hospital death.

Surgical pulmonary embolectomy is rarely performed in the UK, and is associated with significant mortality and morbidity. Preoperative ventilation, cardiogenic shock, and increased duration of bypass were significant predictors of in-hospital death.

Venous thromboembolism, encompassing acute pulmonary embolism (APE) and deep vein thrombosis (DVT), is a potentially fatal disease with complex pathophysiology. Traditionally, the Virchow triad provided a framework for understanding the pathogenic contributors to thrombus formation, which include endothelial dysfunction, alterations in blood flow and blood hypercoagulability. In the last years, it has become apparent that immunity plays a central role in thrombosis, interacting with classical prothrombotic mechanisms, oxidative stress and vascular factors. Thrombosis amplifies inflammation, and exaggerated inflammatory processes can trigger thrombosis mainly due to the activation of leukocytes, platelets, and endothelial cells. APE-related endothelium injury is a major trigger for immune system activation. Endothelium is also a key component mediating inflammatory reaction and it is relevant to maintain vascular permeability. Exaggerated right ventricular wall stress and overload, with coexisting systemic hypotension and hypoxemia, result in myocardial injury and necrosis. Hypoxia, tissue factor activation and cytokine storm are engaged in the thrombo-inflammatory processes. Thrombus development is characterized by inflammatory state vascular wall caused mainly by an early extravasation of leukocytes and intense selectins and cytokines production. Nevertheless, immunity of DVT is well described, little is known about potential chemokine and cellular differences between thrombus that develops in the vein and thrombus that detaches and lodges in the pulmonary circulation being a cause of APE. There is a paucity of data considering inflammatory state in the pulmonary artery wall during an acute episode of pulmonary embolism. The main aim of this review is to summarize the knowledge of immunity in acute phase of pulmonary embolism in experimental models.

Background  In acute pulmonary embolism (PE), echocardiographic identification of right ventricular (RV) dysfunction will inform prognostication and clinical decision-making. Registro Informatizado Enfermedad TromboEmbolica (RIETE) is the world's largest registry of patients with objectively confirmed PE. The reliability of site-reported RV echocardiographic measurements is unknown. We aimed to validate site-reported key RV echocardiographic measurements in the RIETE registry. Methods  Fifty-one randomly chosen patients in RIETE who had transthoracic echocardiogram (TTE) performed for acute PE were included. TTEs were de-identified and analyzed by a core laboratory of two independent observers blinded to site-reported data. To investigate reliability, intraclass correlation coefficients (ICCs) and Bland-Altman plots between the two observers, and between an average of the two observers and the RIETE site-reported data were obtained. Results  Core laboratory interobserver variations were very limited with correlation coefficients >0.8 for all TTE parameters. Agreement was substantial between core laboratory observers and site-reported data for key parameters including tricuspid annular plane systolic excursion (ICC 0.728; 95% confidence interval [CI], 0.594-0.862) and pulmonary arterial systolic pressure (ICC 0.726; 95% CI, 0.601-0.852). Agreement on right-to-left ventricular diameter ratio (ICC 0.739; 95% CI, 0.443-1.000) was validated, although missing data limited the precision of the estimates. Bland-Altman plots showed differences close to zero. Conclusion  We showed substantial reliability of key RV site-reported measurements in the RIETE registry. Ascertaining the validity of such data adds confidence and reliability for subsequent investigations.

Massive pulmonary embolism (MPE) carries significant 30-day mortality and is characterized by acute right ventricular failure, hypotension, and hypoxia, leading to cardiovascular collapse and cardiac arrest. Given the continued high mortality associated with MPE, there has been ongoing interest in utilizing extracorporeal membrane oxygenation (ECMO) to provide oxygenation support to improve hypoxia and offload the right ventricular (RV) pressure in the belief that rapid reduction of hypoxia and RV pressure will improve outcomes. Two modalities can be employed: Veno-arterial-ECMO is a reliable process to decrease RV overload and improve RV function, thus allowing for hemodynamic stability and restoration of tissue oxygenation. Veno-venous ECMO can support oxygenation but is not designed to help circulation. Several societal guidelines now suggest using ECMO in MPE with interventional therapy. There are three strategies for ECMO utilization in MPE: bridge to definitive interventional therapy, sole therapy, and recovery after interventional treatment. The use of ECMO in MPE has been associated with lower mortality in registry reviews, but there has been no significant difference in outcomes between patients treated with and without ECMO in meta-analyses. Considerable heterogeneity in studies is a significant weakness of the available literature. Applying ECMO is also associated with substantial multisystem morbidity due to a systemic inflammatory response, hemorrhagic stroke, renal dysfunction, and bleeding, which must be factored into the outcomes. The application of ECMO in MPE should be combined with an aggressive pulmonary interventional program and should strictly adhere to the current selection criteria.

High-risk pulmonary embolism (PE) is associated with significant morbidity and mortality. Systemic thrombolysis remains the most evidenced-based treatment for haemodynamically unstable PE, but in daily clinical practice, it remains largely underused. In addition, unlike acute myocardial infarction or stroke, a clear time window for reperfusion therapy, including fibrinolysis, for high-risk PE has not been defined either for fibrinolysis or for the more recently incorporated options of catheter-based thrombolysis or thrombectomy. The aim of the present article is to review the current evidence supporting the potential benefit of earlier administration of reperfusion in haemodynamically unstable PE patients and suggest some potential strategies to further explore this issue.

Pulmonary embolism is a frequent cardiovascular disease which in recent years has shown a reduction in the mortality but an increase in the incidence. Due to the optimization of clinical probability scores and the interpretation of the D‑dimer test, unnecessary examinations using computed tomography with respect to the exclusion of an acute pulmonary embolism can be avoided, also in pregnant women. The evaluation of the right ventricle contributes to a risk-adapted treatment. Treatment consists of anticoagulation, alone or in combination with reperfusion treatment, such as systemic thrombolysis and also catheter-assisted or surgical treatment. In addition to acute treatment of pulmonary embolisms, an adequate aftercare is important, particularly for the early detection of long-term sequelae. This review article summarizes the current recommendations of international guidelines for patients with pulmonary embolism, accompanied by clinical case examples and a critical discussion.

Acute pulmonary embolism (PE) is a major cause of morbidity and mortality in Portugal. It is the third most common cause of cardiovascular death after stroke and myocardial infarction. However, the management of acute PE remains poorly standardized, and there is a lack of access to mechanical reperfusion when indicated.

This working group analyzed the current clinical guidelines for the use of percutaneous catheter-directed treatment in this setting and proposed a standardized approach for severe forms of acute PE. This document also proposes a methodology for the coordination of regional resources in order to create an effective PE response network, based on the hub-and-spoke organization design.

This model can be applied at the regional level, but it is desirable to extend it to the national level.

Current guidelines suggest careful risk stratification using a structured clinical approach when selecting patients with pulmonary embolism (PE) for home treatment. The aim of our study was to assess whether PE patients referred to home treatment are appropriately risk-stratified according to guidelines prior to referral and what the real-life course of the disease in these patients is. We included patients with confirmed PE referred to outpatient management and treated with anticoagulants between 2010 and 2019, whose data were collected in a prospective management registry. Using simplified PE severity index and/or signs of right ventricular strain, we classified patients to either appropriate or inappropriate low-risk classes for outpatient management. We compared 30-day mortality, overall mortality, and rates of recurrent thromboembolism or major bleeding between both classes. Among 278 patients, 188 (67.6%) and 90 (32.4%) were classified as appropriate or inappropriate class, respectively. In total, 30-day mortality was low in both groups: 0% in appropriate class and 1.1% in inappropriate class. The overall mortality rate was higher in the inappropriate than in the appropriate class (12.1 vs 0.9/100 patient-years, respectively, P < .001). Rates of recurrent thromboembolism and major bleeding were similar for both classes. We conclude that in real-life, a significant proportion of inappropriate low-risk class PE patients are referred to outpatient management. However, with careful follow-up, early mortality is low, even in home-treated patients inappropriately classified as low-risk.

Pulmonary embolism is a frequent cardiovascular disease which in recent years has shown a reduction in the mortality but an increase in the incidence. Due to the optimization of clinical probability scores and the interpretation of the D‑dimer test, unnecessary examinations using computed tomography with respect to the exclusion of an acute pulmonary embolism can be avoided, also in pregnant women. The evaluation of the right ventricle contributes to a risk-adapted treatment. Treatment consists of anticoagulation, alone or in combination with reperfusion treatment, such as systemic thrombolysis and also catheter-assisted or surgical treatment. In addition to acute treatment of pulmonary embolisms, an adequate aftercare is important, particularly for the early detection of long-term sequelae. This review article summarizes the current recommendations of international guidelines for patients with pulmonary embolism, accompanied by clinical case examples and a critical discussion.

Pulmonary embolism (PE) is a disease with a relatively good prognosis when diagnosed and treated properly. This review aims to analyse available data and combine them into algorithms that physicians can use in the emergency department for quick decision-making in diagnosing and treating PE. The available data show that PE can be excluded through highly sensitive clinical decision rules, i.e. Pulmonary Embolism Rule-Out Criteria (PERC), Wells criteria, and Revised Geneva criteria, combined with D-dimer assessment. In cases where PE could not be excluded through the mentioned strategies, imaging modalities, such as compression ultrasonography (CUS), computed tomographic pulmonary angiography (CTPA), and planar ventilation/perfusion (V/Q) scan, are indicated for a definite diagnosis. Once a diagnosis has been made, treatment of PE depends on its mortality risk as patients are divided into low-, intermediate-, and high-risk cases. High-risk cases are treated for their hemodynamic instability, given parenteral or oral anticoagulant therapy, and are indicated for reperfusion therapy. Intermediate-risk PE is only given parenteral or oral anticoagulants and reperfusion is indicated when anticoagulants fail. Low-risk cases are given oral anticoagulants and based on the Hestia criteria, patients may be discharged and treated as outpatients.

Pulmonary embolism (PE) in pregnant women appears to be increasing. This could be related in part to improved health care allowing more women with risk factors to conceive, as well as increase in the high-risk groups which include pregnancies conceived on artificial reproductive technology, advancing maternal age, obesity, and caesarean deliveries. Prevention and early diagnosis with prompt effective treatment can reduce maternal mortality and improve pregnancy outcome, so that obstetricians should be on the lookout for venous thrombosis and PE, especially when in the majority of cases, risk factors only start to emerge or develop in the course of pregnancy and delivery. Management includes accurate diagnosis with ventilation/perfusion scan and CT pulmonary angiography, followed by effective anticoagulation and more aggressive measures such as thrombolysis as indicated, together with general supportive measures. Postpartum management should cover subsequent health issues, including breastfeeding, contraception, mood changes, and recurrence in subsequent pregnancies.

Left iliac vein compression is associated with left iliac vein thrombosis (IVT), potentially limiting the migration of the thrombus from this stenotic segment to the pulmonary arteries. We sought to investigate the differences in clinical characteristics and risk factors of symptomatic pulmonary embolism (SPE) in patients with deep vein thrombosis (DVT) in different limbs and anatomical locations.

A retrospective analysis was conducted of 1476 patients with acute unilateral lower extremity DVT. Differences of clinical characteristics and risk factors between left-sided and right-sided DVT, IVT, and non-IVT, cases with SPE and cases without SPE were compared. Risk factors for SPE were investigated using logistic regression analysis.

SPE was more common in patients with right-sided DVT than patients with left-sided DVT (13.8% vs 7.0%; P < .001). SPE incidence in left IVT (5.4%) was lower than that in left non-IVT, right IVT, and right non-IVT (12.8%, 10.1%, 16.6%, respectively; P < .001). There was no difference in SPE incidence among patients with left non-IVT, right IVT and right non-IVT (P > .05). In patients with left-sided DVT, male sex was associated with an increased odds of SPE (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.10-2.85; P = .02). IVT, surgery, and immobilization were associated with a decreased odds of SPE (OR, 0.46 [95% CI, 0.28-0.76; P < .01]; OR, 0.55 [95% CI, 0.32-0.95; P = .03]; and OR, 0.53 [95% CI, 0.32-0.86; P = .01]). In patients with right-sided DVT, provoked DVT was associated with a decreased odds of SPE (OR, 0.50; 95% CI, 0.27-0.93; P = .03).

Left IVT is associated with a lower SPE incidence than right-sided DVT. Left IVT and may be a relative protective factor against SPE.

Pulmonary embolism (PE) is characterized by occlusion of blood flow in a pulmonary artery, typically due to a thrombus that travels from a vein in a lower limb. The incidence of PE is approximately 60 to 120 per 100 000 people per year. Approximately 60 000 to 100 000 patients die from PE each year in the US.

PE should be considered in patients presenting with acute chest pain, shortness of breath, or syncope. The diagnosis is determined by chest imaging. In patients with a systolic blood pressure of at least 90 mm Hg, the following 3 steps can be used to evaluate a patient with possible PE: assessment of the clinical probability of PE, D-dimer testing if indicated, and chest imaging if indicated. The clinical probability of PE can be assessed using a structured score or using clinical gestalt. In patients with a probability of PE that is less than 15%, the presence of 8 clinical characteristics (age <50 years, heart rate <100/min, an oxygen saturation level of > 94%, no recent surgery or trauma, no prior venous thromboembolism event, no hemoptysis, no unilateral leg swelling, and no estrogen use) identifies patients at very low risk of PE in whom no further testing is needed. In patients with low or intermediate clinical probability, a D-dimer level of less than 500 ng/mL is associated with a posttest probability of PE less than 1.85%. In these patients, PE can be excluded without chest imaging. A further refinement of D-dimer threshold is possible in patients aged 50 years and older, and in patients with a low likelihood of PE. Patients with a high probability of PE (ie, >40% probability) should undergo chest imaging, and D-dimer testing is not necessary. In patients with PE and a systolic blood pressure of 90 mm Hg or higher, compared with heparin combined with a vitamin K antagonist such as warfarin followed by warfarin alone, direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, are noninferior for treating PE and have a 0.6% lower rate of bleeding. In patients with PE and systolic blood pressure lower than 90 mm Hg, systemic thrombolysis is recommended and is associated with an 1.6% absolute reduction of mortality (from 3.9% to 2.3%).

In the US, PE affects approximately 370 000 patients per year and may cause approximately 60 000 to 100 000 deaths per year. First-line therapy consists of direct oral anticoagulants such as apixaban, edoxaban, rivaroxaban, or dabigatran, with thrombolysis reserved for patients with systolic blood pressure lower than 90 mm Hg.

Acute pulmonary embolism (PE) affects more than 100 000 people in the United States annually and is the third leading cardiovascular cause of death. The standard management for PE is systemic anticoagulation therapy. However, a subset of patients experience hemodynamic decompensation, despite conservative measures. Traditionally, these patients have been treated with systemic administration of thrombolytic agents or open cardiac surgery, although attempts at endovascular treatment have a long history that dates back to the 1960s. The technology for catheter-based therapy for acute PE is rapidly evolving, with multiple devices approved over the past decade. Currently available devices fall into two broad categories of treatment methods: catheter-directed thrombolysis and percutaneous suction thrombectomy. Catheter-directed thrombolysis is the infusion of thrombolytic agents directly into the occluded pulmonary arteries to increase local delivery and decrease the total dose. Suction thrombectomy involves the use of small- or large-bore catheters to mechanically aspirate a clot from the pulmonary arteries without the need for a thrombolytic agent. A thorough understanding of the various risk stratification schemes and the available evidence for each device is critical for optimal treatment of this complex entity. Multiple ongoing studies will improve our understanding of the role of catheter-based therapy for acute PE in the next 5-10 years. A multidisciplinary approach through PE response teams has become the management standard at most institutions. An invited commentary by Bulman and Weinstein is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Pulmonary embolism is a potentially lethal manifestation of venous thromboembolic disease. It is one of the three main causes of cardiovascular morbidity and mortality in developed countries. Over the years, better diagnostic and risk stratification measures were implemented. A generous range of new treatment options is becoming available, particularly for management of massive pulmonary embolism. Nonetheless, clinicians often face uncertainty in clinical practice due to lack of scientific support for available treatment options. The aim of this article is to review management of massive pulmonary embolism.

The central location, size, and instability of saddle pulmonary embolism (SPE) have raised significant concerns regarding its clinical, hemodynamic effects as well as optimal management. Pulmonary embolism (PE) guidelines barely address such concerns. We aimed to pool the available data on the clinical behavior and outcomes of SPE and study the effects of various treatment modalities on mortality outcomes.

PubMed, Scopus, and Google Scholar were searched for articles (any date up to February 28, 2022) reporting patients with SPE. Data on SPE demographics, clinical characteristics, management, and outcomes were extracted and analyzed.

Results from all SPE cases: A total of 5251 patients from 194 studies were included in the review. Dyspnea (57 %) was the most prevalent symptom. Massive and submassive PE comprised 9.7 % and 45.8% of cases, respectively. Thrombolytic therapy (TT) was administered in 18.1 %, and thrombectomy was performed in 16 % of cases. SPE-related mortality was observed in 4.6 %, late decompensation in 9.5 %, and PE recurrence in 4.5 % of cases. Female sex (61.5 % vs. 41.3 %, p = 0.019), hypoxemia (90 % vs. 59.2 %, p < 0.001), massive PE features (89.7 % vs. 30.1 %, p < 0.001), associated chronic kidney disease (CKD) (10.3 % vs. 1.4 %, p = 0.002), and the need for mechanical ventilation (28.2 % vs. 13.1 %, p = 0.02) were significantly associated with increased mortality. The use of TT was significantly associated with increased survival (27.1 % vs. 12.5 %, p < 0.001). In a multivariate logistic regression model, massive PE features significantly increased the odds of death (OR: 29.3, CI: 4.86-181.81, p < 0.001), whereas, treatment with anticoagulation (AC) alone (OR: 0.1, CI: 0.027-0.356, p < 0.001), TT (OR: 0.065, CI: 0.019-0.26, p < 0.001), surgical thrombectomy (ST) (OR: 0.047, CI: (0.010-0.23), p < 0.001), or percutaneous thrombectomy (PT) (OR: 0.12, CI: 0.020-0.84, p = 0.032) significantly decreased odds of death. Results from a meta-analysis of observational studies: Meta-analysis of the included 17 observational studies revealed an overall 10 % (95 % CI: 4.56-16.89) SPE prevalence among all PE cases. The overall SPE-related mortality rate was 8 % (95 % CI: 5.26-10.96). Massive PE was observed in 13.3 % (95 % CI: 5.56-23.70), PE recurrence in 5.1 % (95 % CI: 2.22-9.05), and late decompensation in 11 % (95 % CI: 3.43-22.34) of patients.

SPE comprises 10 % of all PE cases. Despite its ominous radiologic appearance, the clinical, hemodynamic, and mortality outcomes of SPE seem comparable to that of other PE types in general. The presence of massive PE features is the main predictor of mortality in SPE patients. AC, TT, ST, and PT are all associated with decreased odds of death from SPE.

Pulmonary embolism represents a common life-threatening condition. Prompt identification and treatment of this pathological condition are mandatory. In cases of massive pulmonary embolism and hemodynamic instability or right heart failure, interventional radiology treatment for pulmonary embolism is emerging as an alternative to medical treatment (systemic thrombolysis) and surgical treatment. Interventional radiology techniques include percutaneous endovascular catheter directed therapies as selective thrombolysis and thrombus aspiration, which can prove useful in cases of failure or infeasibility of medical and surgical approaches.

Acute pulmonary embolism (APE) is a major cause of acute morbidity and mortality. APE results in long-term morbidity in up to 50% of survivors, known as post-pulmonary embolism (post-PE) syndrome.  APE can be classified according to the short-term (30-day) risk of mortality, based on a variety of clinical, imaging and laboratory findings. Most mortality and morbidity is concentrated in high-risk (massive) and intermediate-risk (submassive) APE. The first-line treatment for APE is systemic anticoagulation.  High-risk (massive) APE accounts for less than 10% of APE cases and is a life-threatening medical emergency, requiring immediate reperfusion treatment to prevent death. Systemic thrombolysis is the recommended treatment for high-risk (massive) APE. However, only a minority of the people affected receive systemic thrombolysis, due to comorbidities or the 10% risk of major haemorrhagic side effects. Of those who do receive systemic thrombolysis, 8% do not respond in a timely manner. Surgical pulmonary embolectomy is an alternative reperfusion treatment, but is not widely available.  Intermediate-risk (submassive) APE represents 45% to 65% of APE cases, with a short-term mortality rate of around 3%. Systemic thrombolysis is not recommended for this group, as major haemorrhagic complications outweigh the benefit. However, the people at higher risk within this group have a short-term mortality of around 12%, suggesting that anticoagulation alone is not an adequate treatment. Identification and more aggressive treatment of people at intermediate to high risk, who have a more favourable risk profile for reperfusion treatments, could reduce short-term mortality and potentially reduce post-PE syndrome. Catheter-directed treatments (catheter-directed thrombolysis and catheter embolectomy) are minimally invasive reperfusion treatments for high- and intermediate-risk APE. Catheter-directed treatments can be used either as the primary treatment or as salvage treatment after failure of systemic thrombolysis. Catheter-directed thrombolysis administers 10% to 20% of the systemic thrombolysis dose directly into the thrombus in the lungs, potentially reducing the risks of haemorrhagic side effects. Catheter embolectomy mechanically removes the thrombus without the need for thrombolysis, and may be useful for people with contraindications for thrombolysis.  Currently, the benefits of catheter-based APE treatments compared with existing medical and surgical treatment are unclear despite increasing adoption of catheter treatments by PE response teams. This review examines the evidence for the use of catheter-directed treatments in high- and intermediate-risk APE. This evidence could help guide the optimal treatment strategy for people affected by this common and life-threatening condition.

To assess the effects of catheter-directed therapies versus alternative treatments for high-risk (massive) and intermediate-risk (submassive) APE.

We used standard, extensive Cochrane search methods. The latest search was 15 March 2022.

We included randomised controlled trials (RCTs) of catheter-directed therapies for the treatment of high-risk (massive) and intermediate-risk (submassive) APE. We excluded catheter-directed treatments for non-PE. We applied no restrictions on participant age or on the date, language or publication status of RCTs.

We used standard Cochrane methods. The main outcomes were all-cause mortality, treatment-associated major and minor haemorrhage rates based on two established clinical definitions, recurrent APE requiring retreatment or change to a different APE treatment, length of hospital stay, and quality of life. We used GRADE to assess certainty of evidence for each outcome.

We identified one RCT (59 participants) of (ultrasound-augmented) catheter-directed thrombolysis for intermediate-risk (submassive) APE. We found no trials of any catheter-directed treatments (thrombectomy or thrombolysis) in people with high-risk (massive) APE or of catheter-based embolectomy in people with intermediate-risk (submassive) APE. The included trial compared ultrasound-augmented catheter-directed thrombolysis with alteplase and systemic heparinisation versus systemic heparinisation alone. In the treatment group, each participant received an infusion of alteplase 10 mg or 20 mg over 15 hours. We identified a high risk of selection and performance bias, low risk of detection and reporting bias, and unclear risk of attrition and other bias. Certainty of evidence was very low because of risk of bias and imprecision.  By 90 days, there was no clear difference in all-cause mortality between the treatment group and control group. A single death occurred in the control group at 20 days after randomisation, but it was unrelated to the treatment or to APE (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.01 to 7.96; 59 participants). By 90 days, there were no episodes of treatment-associated major haemorrhage in either the treatment or control group. There was no clear difference in treatment-associated minor haemorrhage between the treatment and control group by 90 days (OR 3.11, 95% CI 0.30 to 31.79; 59 participants). By 90 days, there were no episodes of recurrent APE requiring retreatment or change to a different APE treatment in the treatment or control group. There was no clear difference in the length of mean total hospital stay between the treatment and control groups. Mean stay was 8.9 (standard deviation (SD) 3.4) days in the treatment group versus 8.6 (SD 3.9) days in the control group (mean difference 0.30, 95% CI -1.57 to 2.17; 59 participants). The included trial did not investigate quality of life measures.  AUTHORS' CONCLUSIONS: There is a lack of evidence to support widespread adoption of catheter-based interventional therapies for APE. We identified one small trial showing no clear differences between ultrasound-augmented catheter-directed thrombolysis with alteplase plus systemic heparinisation versus systemic heparinisation alone in all-cause mortality, major and minor haemorrhage rates, recurrent APE and length of hospital stay. Quality of life was not assessed.  Multiple small retrospective case series, prospective patient registries and single-arm studies suggest potential benefits of catheter-based treatments, but they provide insufficient evidence to recommend this approach over other evidence-based treatments. Researchers should consider clinically relevant primary outcomes (e.g. mortality and exercise tolerance), rather than surrogate markers (e.g. right ventricular to left ventricular (RV:LV) ratio or thrombus burden), which have limited clinical utility. Trials must include a control group to determine if the effects are specific to the treatment.

Patients with acute venous thromboembolism (VTE) require anticoagulant therapy to prevent recurrent VTE and death, which exposes them to an inherent increased risk of bleeding. Identification of patients at high risk of bleeding, and mitigating this risk, is an essential component of the immediate and long-term therapeutic management of VTE. The bleeding risk can be estimated by either implicit judgment, weighing individual predictors (clinical variables or biomarkers), or by risk prediction tools developed for this purpose. Management of bleeding risk in clinical practice is, however, far from standardized. International guidelines are contradictory and lack clear and consistent guidance on the optimal management of bleeding risk. This report of the ISTH subcommittee on Predictive and Diagnostic Variables in Thrombotic Disease summarizes the evidence on the prediction of bleeding in VTE patients. We systematically searched the literature and identified 34 original studies evaluating either predictors or risk prediction models for prediction of bleeding risk on anticoagulation in VTE patients. Based on this evidence, we provide recommendations for the standardized management of bleeding risk in VTE patients.

Acute pulmonary thromboembolism (PTE) is an important cause of morbidity and mortality that can reduce quality of life due to long-term complications during and after treatment discontinuation.

The aim of this study was to evaluate patients for these complications before discontinuing treatment and determine the necessity of computed tomography pulmonary angiography (CTPA) imaging.

This retrospective study included 116 patients over the age of 18 who received anticoagulant treatment for at least 3 months and presented for treatment discontinuation to the Atatürk University Research Hospital Chest Diseases Outpatient Clinic between January 2015 and September 2019.

CTPA performed at treatment discontinuation showed complete thrombus resolution with treatment in 73 patients (62.9%). High pulmonary artery obstruction index (PAOI) at diagnosis was statistically associated with findings of residual or chronic thrombus on CTPA at treatment discontinuation (p = 0.001). In the differentiation of patients with residual/chronic thrombus and those with thrombus resolution, D-dimer at a cut-off value of 474 µg/L had 60% sensitivity and 70% specificity. At a cut-off value of 35.5 mmHg, mean pulmonary artery pressure on echocardiography had sensitivity and specificity of 72% and 77%, respectively. At a cut-off of 23.75, PAOI had sensitivity and specificity of 93% and 69%, respectively.

In addition to physical examination findings, D-dimer and echocardiography were guiding parameters in the evaluation of treatment discontinuation and thrombus resolution in patients presenting to the outpatient clinic for discontinuation of treatment for acute PTE. PAOI at diagnosis may be another important guiding parameter in addition to these examinations.

Identifying right ventricle (RV) abnormalities is important to stratifying pulmonary embolism (PE) severity. Disposition decisions are influenced by concerns about early deterioration. Triaging strategies, like the Simplified Pulmonary Embolism Severity Index (sPESI), do not include RV assessments as predictors or early deterioration as outcome(s). We aimed to (1) determine if RV assessment variables add prognostic accuracy for 5-day clinical deterioration in patients classified low risk by sPESI, and (2) determine the prognostic importance of RV assessments compared to other variables and to each other.

We identified low risk sPESI patients (sPESI = 0) from a prospective PE registry. From a large field of candidate variables, we developed, and compared prognostic accuracy of, full and reduced random forest models (with and without RV assessment variables, respectively) on a validation database. We reported variable importance plots from full random forest and provided odds ratios for statistical inference of importance from multivariable logistic regression. Outcomes were death, cardiac arrest, hypotension, dysrhythmia, or respiratory failure within 5 days of PE.

Of 1736 patients, 610 (35.1%) were low risk by sPESI and 72 (11.8%) experienced early deterioration. Of the 610, RV abnormality was present in 157 (25.7%) by CT, 121 (19.8%) by echocardiography, 132 (21.6%) by natriuretic peptide, and 107 (17.5%) by troponin. For deterioration, the receiver operating characteristics for full and reduced random forest prognostic models were 0.80 (0.77-0.82) and 0.71 (0.68-0.73), respectively. RV assessments were the top four in the variable importance plot for the random forest model. Echocardiography and CT significantly increased predicted probability of 5-day clinical deterioration by the multivariable logistic regression.

A PE triaging strategy with RV imaging assessments had superior prognostic performance at classifying low risk for 5-day clinical deterioration versus one without.