Intravenous adenosine induces stable myocardial hyperemia for coronary microvascular function testing. Iodinated radiographic contrast media induce transient, submaximal hyperemia. We assessed the feasibility, diagnostic value, and potential cost-effectiveness of contrast-derived indices of microvascular function.

Coronary flow reserve, index of microvascular resistance, and microvascular resistance reserve were assessed using a diagnostic guidewire. Intracoronary bolus thermodilution injections were performed at rest, immediately after an 8-mL bolus of iohexol, repeated after a second 8-mL bolus, and during intravenous adenosine infusion. Receiver operating characteristic analyses assessed the discriminatory ability of the contrast-derived indices (contrast-derived coronary flow reserve, contrast-derived index of microcirculatory resistance, contrast-derived microvascular resistance reserve) to detect abnormal adenosine-derived indices (coronary flow reserve <2.0, index of microvascular resistance ≥25, and microvascular resistance reserve <2.1).

Among 106 coronary arteries from 93 patients (median age 63 years; 62% female; 13% with diabetes), 88% of assessments were undertaken in the left anterior descending artery. Median fractional flow reserve was 0.88 (interquartile range, 0.85-0.92). Contrast-derived coronary flow reserve <2.0 (area under the curve 0.81; sensitivity 67%, specificity 80%, positive predictive value 40%, negative predictive value 92%), contrast-derived index of microcirculatory resistance >47 (area under the curve 0.82; 80%, 79%, 60%, 91%), and contrast-derived microvascular resistance reserve <1.9 (area under the curve 0.82; 67%, 89%, 35%, 97%) were best for predicting their adenosine-derived counterpart indices. There was good correlation on repeatability testing from the second contrast bolus. A hybrid approach reduced adenosine use by 40%, saving $30 800 (USA) or £8000 (UK) per 1000 vessels assessed.

Contrast-derived indices have high specificity and negative predictive value, enabling rapid exclusion of microvascular dysfunction. This method is feasible, clinically useful and cost-saving compared with routine adenosine testing.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04674449.

Contrast-induced acute kidney injury (CI-AKI) is a significant concern during percutaneous coronary intervention (PCI) procedures. The novel Mehran 2 pre-procedural risk score, an updated version of the original Mehran score, shows promise as a predictive tool. However, its effectiveness specifically in acute coronary syndrome (ACS) patients requires further investigation. This study aims to evaluate the performance of Mehran 2 pre-procedure risk score compared to original score in predicting CI-AKI risk in acute coronary syndrome patients undergoing PCI.

A prospective cohort study was conducted with patients with ACS undergoing PCI, who were followed up for 90 days (December 2019-February 2021). The Mehran 2 CI-AKI risk score with pre-procedure data was compared with the original Mehran score. Receiver operating characteristic (ROC) curve and area under the ROC curve (AUC-ROC) were used to evaluate the discriminative capacity.

192 patients were analyzed and 33% (n = 64) developed CI-AKI. CI-AKI outcome was associated with advanced age, arterial hypertension, chronic kidney disease, troponin T, hemodynamic instability, serum hemoglobin, serum creatinine, and higher both Mehran scores. Both scores demonstrated good agreement. The original Mehran score demonstrated superior CI-AKI stratification with higher sensitivity (85.94%) and specificity (60.16%) compared to the Mehran 2 pre-procedural score (sensitivity 50%, specificity 75%). Significant differences were observed in the discriminative performance between both scores.

Sociodemographic, clinical, and laboratory variables were associated with CI-AKI. The original Mehran score demonstrated more consistent discriminative capacity for predicting CI-AKI risk in ACS patients undergoing PCI compared to the Mehran 2 pre-procedural score.

Contrast-induced nephropathy (CIN), also called as contrast associated-acute kidney injury (CA-AKI) is a common complication following cardiac procedures. KDIGO guidelines define CIN as a ≥25% increase in serum creatinine or an absolute increase of at least 0.5 mg/dl 48-72 h post-contrast administration. The single most effective measure in preventing CIN is peri-procedural intravascular hydration typically from 12 h before to 24 h after contrast media exposure but has limitations. Recently, the RenalGuard (RG) system has emerged as a new tool, demonstrating safer and more efficient hydration and reducing the incidence of AKI caused by CIN.

We conducted this meta-analysis on the effectiveness of the RG system in preventing CIN in patients undergoing cardiac interventions.

A comprehensive literature search of PubMed (MEDLINE), Science Direct, and Embase was conducted from its inception until February 2024 for randomized controlled trials (RCTs) including patients aged >18 years undergoing cardiac procedures with underlying chronic kidney disease (CKD), estimated glomerular filtration rate (eGFR) 20-60 ml/min/1.73 m2 and left ventricular ejection fraction (LVEF) >50%. The outcomes of interest were risk of CIN, risk of renal replacement therapy (RRT), in-hospital mortality and 30-day mortality, major adverse cardiovascular events (MACE), changes in serum creatinine (sCr) levels, and incidence of pulmonary edema. A random-effects meta-analysis was performed using Review Manager (RevMan) [Computer Program] Version 5.4 Cochrane Collaboration.

A total of 9 RCTs including 3,215 patients with CKD undergoing cardiac procedures on volume expansion strategies were included with 1,802 patients on the RG system and 1,413 patients using alternate volume expansion techniques. Pooled analysis of 9 RCTs reported a significantly lower risk of CIN in patients using the RG system vs. control [OR 0.51 (0.35, 0.74), P = 0.0004; I2 = 55%]. There was no significant difference in the risks of RRT, in-hospital mortality, 30-day MACE, pulmonary edema, or change in sCr levels.

This meta-analysis indicates the beneficial utilization of the RG system in populations with moderate-to-high risk and underlying CKD undergoing cardiac interventions in preventing CIN. However, it did not demonstrate a notable impact on mortality, RRT, MACE, pulmonary edema, and sCr levels when compared to the control group.

Contrast-induced nephropathy (CIN) remains a serious complication following percutaneous coronary intervention (PCI), often leading to poor outcomes. Although the overall incidence of CIN is low, the risk can be significantly higher in certain susceptible cohorts.

This prospective observational analytic study enrolled 174 consecutive eligible patients. The study selectively included diabetic patients with heart failure who are receiving regular diuretic therapy, being scheduled for elective coronary angiography (CAG) and/or PCI. CIN occurred in 24.7% of the study participants. CIN patients had significantly higher baseline osmolarity compared to those who did not develop CIN. After adjusting for other factors, pre-procedure osmolarity ≥ 302.3 mOsm/L, higher CHA2DS2VA score, and larger contrast volume proved to be independent predictors for CIN with an odds ratio and 95% confidence interval of 7.07 (2.47-20.26), 3.99 (2.02-7.9), and 1.01 (1.0-1.014), respectively.

In patients at high risk for CIN, serum osmolarity can serve as a practical stratification tool for CIN risk before elective CAG or PCI. Future studies should evaluate whether targeting a specific pre-procedural osmolarity threshold can reduce the risk of post-PCI CIN.

The triglyceride glucose (TyG) index is a biomarker of insulin resistance and is associated with an increased risk of cardiovascular events. Contrast-induced nephropathy (CIN) is an important complication that causes poor outcomes in patients undergoing percutaneous coronary intervention (PCI). In this study, we aimed to investigate the relationship between the TyG index and CIN and mortality in patients who underwent PCI due to chronic total coronary occlusion (CTO).

Two hundred eighteen individuals from three separate medical centers who underwent procedural PCI between February 2010 and April 2012 and had a CTO lesion in at least one coronary artery were recruited. According to the TyG index, patients were divided into two groups. Patients with a TyG index ≥ 8.65 were included in Group 1, and patients with a TyG index < 8.65 were included in Group 2. Patients were followed up for 96 months. The main outcome was the development of CIN and mortality.

The mean age of the patients (65.8 ± 10.94 vs. 61.68 ± 11.4, P = 0.009), diabetes mellitus (60 [44.8%] vs. 11 [13.1%], P < 0.001), and dyslipidemia rates (52 [38.8%] vs. 21 [25%], P = 0.036) were higher in group 1. In multivariable logistic regression analysis, it was seen that age (OR = 1.04, 95% CI = 1.01-1.08, P = 0.020), chronic kidney disease (OR = 2.34, 95% CI = 1.02-5.33, P = 0.044), peripheral artery disease (OR = 5.66, 95% CI = 1.24-25.91, p = 0.026), LVEF (OR = 0.95, 95% CI = 0.92-0.99, P = 0.005), LDL cholesterol levels (OR = 1.00, 95%CI = 1.00-1.02, P = 0.024) and TyG index (OR = 2.17, 95% CI = 1.21-3.89, P = 0.009) were independent predictors of the development of CIN.

Our study demonstrates a correlation between the TyG index and the prevalence of CIN in patients with CTO undergoing PCI. Adding the TyG index to the routine clinical evaluation of patients with CTO undergoing PCI may help protect patients from the development of CIN.

The incidence of contrast-induced acute kidney injury (CI-AKI) in the general population ranges from 0.6 to 2.3%, whereas for specific high-risk patients, the incidence can reach more than 30-40%. Ultrasound measurements of the development of CI-AKI after contrast-enhanced imaging for diagnosis in the emergency department (ED) have yet to be adequately studied. Accordingly, we aimed to evaluate the usefulness of Doppler ultrasound measurements for predicting CI-AKI in patients with normal renal function.

This prospective, observational, single-center study was conducted in the ED of a tertiary teaching and research hospital between 1 January and 1 July 2024. All patients who presented to the tertiary training and research hospital ED, who were admitted to the hospital with a decision to undergo contrast-enhanced tomography for diagnosis, and who did not meet any exclusion criteria were included in the study. Patients included in the study were evaluated by ultrasonographic measurements (interlobar renal artery peak systolic velocity (PSV), interlobar renal artery end-diastolic velocity (EDV), inferior vena cava (IVC) collapsibility index, and renal resistive index (RRI)).

The postcontrast RRI cutoff values were calculated to predict CI-AKI. The area under the curve (AUC) for the postcontrast RRI was 0.914, and the cutoff value for the postcontrast RRI was 0.70 (≥), exhibiting 72.7% sensitivity and 95.6% specificity.

Postcontrast RRI ultrasound measurements performed after diagnostic contrast imaging in the ED show high specificity in predicting CI-AKI development. Postcontrast ultrasound measurements may predict CI-AKI development, allowing further measures to be taken. Further studies are needed to confirm these findings.

Clinical trial number: not applicable.

Circulating proenkephalin (PENK) is a stable endogenous polypeptide with fast response to glomerular dysfunction and tubular damage. This study examined the predictive value of PENK for renal outcomes and mortality in patients with acute coronary syndrome (ACS).

Proenkephalin was measured in plasma in a prospective multicentre ACS cohort from Switzerland (n = 4787) and in validation cohorts from the UK (n = 1141), Czechia (n = 927), and Germany (n = 220). A biomarker-enhanced risk score (KID-ACS score) for simultaneous prediction of in-hospital acute kidney injury (AKI) and 30-day mortality was derived and externally validated.

On multivariable adjustment for established risk factors, circulating PENK remained associated with in-hospital AKI [per log2 increase: adjusted odds ratio 1.53, 95% confidence interval (CI) 1.13-2.09, P = .007] and 30-day mortality (adjusted hazard ratio 2.73, 95% CI 1.85-4.02, P < .001). The KID-ACS score integrates PENK and showed an area under the receiver operating characteristic curve (AUC) of .72 (95% CI .68-.76) for in-hospital AKI and .91 (95% CI .87-.95) for 30-day mortality in the derivation cohort. Upon external validation, KID-ACS achieved similarly high performance for in-hospital AKI (Zurich: AUC .73, 95% CI .70-.77; Czechia: AUC .75, 95% CI .68-.81; Germany: AUC .71, 95% CI .55-.87) and 30-day mortality (UK: AUC .87, 95% CI .83-.91; Czechia: AUC .91, 95% CI .87-.94; Germany: AUC .96, 95% CI .92-1.00), outperforming the contrast-associated AKI score and the Global Registry of Acute Coronary Events 2.0 score, respectively.

Circulating PENK offers incremental value for predicting in-hospital AKI and mortality in ACS. The simple six-item KID-ACS risk score integrates PENK and provides a novel tool for simultaneous assessment of renal and mortality risk in patients with ACS.

Contrast-induced acute kidney injury (CI-AKI) is a common complication of iodinated contrast administration during coronary procedures, especially in patients with diabetes mellitus (DM). Besides periprocedural hydration and statins, there are no other pharmacological strategies with consistent results to prevent CI-AKI up to date. This study aims to evaluate the efficacy of chronic use of sodium-glucose co-transporter 2 (SGLT2) inhibitors on the prevention of CI-AKI in patients with type 2 DM following coronary procedures.

A systematic literature search of MEDLINE, Google Scholar, Embase, and Cochrane Library was performed. Relevant observational studies and randomized controlled studies (RCTs) were identified. Results were pooled using a random-effect model meta-analysis. Subgroup analyses were performed to evaluate the potential benefit of SGLT2 inhibitors on the prevention of CI-AKI in patients undergoing urgent or elective coronary angiography/percutaneous coronary interventions (CAG/PCI).

Seven observational studies and one randomized controlled trial with 2740 patients were included. Chronic treatment (minimum duration 2 weeks to 6 months) with an SGLT2 inhibitor was associated with a significantly reduced risk of CI-AKI in diabetic patients undergoing coronary procedures compared with the control group [risk ratio (RR) 0.48; 95% confidence interval (CI) 0.39-0.59; p < 0.001). Results of subsequent subgroup analysis showed a significant reduction in the incidence of CI-AKI in diabetic patients undergoing both elective CAG/PCI (RR 0.49; 95% CI 0.35-0.68; p<0.001) and urgent CAG/PCI (RR 0.48; 95% Cl 0.35-0.66; p < 0.001).

Chronic use of SGLT2 inhibitors may be preventative against the incidence of CI-AKI in patients with type 2 DM undergoing coronary interventions. Further RCTs are needed to confirm our findings.

Acute kidney injury (AKI) complicates transcatheter aortic valve replacement (TAVR), leading to higher mortality. The incidence and effects of AKI on clinical outcomes in patients undergoing TAVR without chronic kidney disease (CKD) are unclear. We aimed to determine the association between AKI and in-hospital outcomes in patients with TAVR using propensity score matching (PSM).

Using International Classification of Diseases-10th Revision codes, we queried the National Inpatient Sample for TAVR performed between 2016 and 2021. Patients were divided into two groups according to perioperative AKI development. Patients with CKD or on permanent hemodialysis at baseline were excluded. We conducted 1:1 PSM to assemble a cohort of patients with similar baseline characteristics. Multivariate logistic regression was used to assess the association between AKI and in-hospital outcomes. Sensitivity analysis was conducted to evaluate the robustness of our inferences.

Of 47,372 unweighted patient admissions for TAVR, 1617 (3.41%) had a concomitant diagnosis of AKI. The incidence of AKI decreased from 4.82 to 3.18% from 2016 to 2021 (P-trend < 0.01). Before PSM, patients with AKI had a significantly higher rate of in-hospital mortality compared with those without AKI (6.12% vs. 0.48%, respectively; odds ratio [OR] 8.59, 95% confidence interval [CI] 6.32-11.68). Using the PSM algorithm, 1579 well-matched patients were included in each group. After PSM, an association was observed between patients with TAVR and concomitant AKI and a higher risk of in-hospital mortality (6.21% vs. 1.08%, respectively; OR 5.96; 95% CI 3.54-10.04). In subgroup analyses stratified according to age (≤ 80 and > 80 years), sex (male/female), and hypertension status, consistent associations were observed between AKI and the risk of in-hospital mortality. AKI patients were at higher risk for acute myocardial infarction (OR 1.78, 95% CI 1.35-2.34), major bleeding (OR 1.62, 95% CI 1.13-2.33), blood transfusion (OR 1.65, 95% CI 1.28-2.11), and cardiogenic shock (OR 3.73, 95% CI 2.77-5.01). No significant betweengroup differences were observed in stroke (P = 0.12).

AKI was a strong predictor of in-hospital mortality in patients undergoing TAVR without CKD and was associated with higher post-procedure complication rates.

Introduction: Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) requires advanced techniques and prolonged procedural efforts, often necessitating high contrast volumes, which may increase the risk of contrast-associated acute kidney injury (CA-AKI). However, evidence suggests that factors beyond contrast exposure contribute to CA-AKI, though data specific to CTO PCI remain limited. Methods: Patients undergoing contemporary CTO PCI at our university-affiliated tertiary care center were enrolled. CA-AKI was defined according to KDIGO criteria, and patients were stratified based on the presence of postprocedural CA-AKI. Baseline and procedural characteristics, including osmotic factors, were compared between the groups. The primary outcome was all-cause mortality at one year, and the secondary outcome was all-cause mortality at three years. Results: A total of 145 patients were enrolled, with a mean age of 67 years, and 75% were male. Baseline creatinine levels, electrolytes, and osmotic factors did not differ significantly between groups. Lesion parameters and J-CTO scores were also comparable. The contrast volume and procedural duration were numerically higher in patients who developed CA-AKI. Patients with CA-AKI received a higher radiation dose (22.1 vs. 13.2 Gy·cm2, p = 0.041). CA-AKI emerged as an independent predictor of all-cause mortality at one year (adjusted HR 5.3, CI [1.52-18.51], p = 0.009) but not at three years. Conclusions: In this retrospective analysis, CA-AKI was an independent predictor of all-cause mortality at one year following CTO PCI but lost predictive value at three years. Baseline renal function and contrast volume alone did not predict CA-AKI. Instead, procedural complexity, reflected by higher radiation exposure, was associated with an elevated risk of CA-AKI.

To evaluate the efficacy of EECP in the prevention of contrast-induced nephropathy (CIN) in patients with chronic kidney disease (CKD).

A prospective trial was undertaken in the participants. A total of 280 patients with an estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 who underwent percutaneous coronary artery procedures were enrolled and divided into two groups: the control group (n = 100) and the EECP group (n = 180). All patients received extracellular fluid volume expansion therapy with 0.9% normal saline, and patients in the EECP groups were also treated with EECP. The renal function indexes of the two groups were determined 48-72 h after coronary artery procedures.

In the EECP group, the BUN and serum creatinine (Scr) after coronary artery procedures were significantly lower than those before coronary artery procedures (BUN: 8.4 ± 3.5 vs. 6.6 ± 2.7 mmol/L, p < 0.001; Scr: 151.9 ± 44.7 vs. 144.5 ± 48.3 μmol/L, p < 0.001), while the eGFR was significantly increased (43.6 ± 11.4 vs. 47.1 ± 13.9 ml/min/1.73 m2, p < 0.001). The degree of Scr elevation was lower in the EECP group than in the control group (12.4 ± 15.0 vs. 20.9 ± 24.8 μmol/L, p = 0.026). Additionally, the EECP group had a lower incidence of post-procedures Scr elevation than the control group (36.5 vs. 48.0%, p = 0.042), a higher incidence of post-procedures eGFR elevation (62.2 vs. 48.0%, p = 0.021), and a lower risk of CIN (1.1 vs. 6.0%, p = 0.019).

EECP therapy has a protective effect on renal function and can reduce the risk of CIN in patients with CKD.

Adverse drug events (ADEs) pose a significant challenge in current clinical practice. Machine learning (ML) has been increasingly used to predict specific ADEs using electronic health record (EHR) data. This systematic review provides a comprehensive overview of the application of ML in predicting specific ADEs based on EHR data.

A systematic search of PubMed, Web of Science, Embase, and IEEE Xplore was conducted to identify relevant articles published from the inception to 20 May 2024. Studies that developed ML models for predicting specific ADEs or ADEs associated with particular drugs were included using EHR data.

A total of 59 studies met the inclusion criteria, covering 15 drugs and 15 ADEs. In total, 38 machine learning algorithms were reported, with random forest (RF) being the most frequently used, followed by support vector machine (SVM), eXtreme gradient boosting (XGBoost), decision tree (DT), and light gradient boosting machine (LightGBM). The performance of the ML models was generally strong, with an average area under the curve (AUC) of 76.68% ± 10.73, accuracy of 76.00% ± 11.26, precision of 60.13% ± 24.81, sensitivity of 62.35% ± 20.19, specificity of 75.13% ± 16.60, and an F1 score of 52.60% ± 21.10. The combined sensitivity, specificity, diagnostic odds ratio (DOR), and AUC from the summary receiver operating characteristic (SROC) curve using a random effects model were 0.65 (95% CI: 0.65-0.66), 0.89 (95% CI: 0.89-0.90), 12.11 (95% CI: 8.17-17.95), and 0.8069, respectively. The risk factors associated with different drugs and ADEs varied.

Future research should focus on improving standardization, conducting multicenter studies that incorporate diverse data types, and evaluating the impact of artificial intelligence predictive models in real-world clinical settings.

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024565842, identifier CRD42024565842.

Contrast-associated acute kidney injury (CA-AKI) is a major complication following coronary procedures. We aimed to evaluate the effectiveness of a combination of urine flow rate-(UFR) guided hydration (RenalGuardTM) and device-based contrast media (CM) reduction (DyeVertTM) in CA-AKI prevention.

Stable high-risk patients undergoing coronary procedures with the use of DyeVertTM and RenalGuardTM were prospectively included (Combined group) and matched with a similar cohort of patients treated only with RenalGuardTM in whom CM volume was controlled by operator-dependent strategies (Control group). CA-AKI was defined as a serum creatinine increase ≥0.3 mg/dL at 48 h.

Overall, 55 patients were enrolled and matched with comparable controls. Patients in the Combined group were exposed to a lower CM dose (Control: 55 [30-90] mL vs. Combined: 42.1 [24.9-59.4] mL; p = 0.024). A significant interaction was found between treatment allocation and serum creatinine changes (p = 0.048). CA-AKI occurred in five (9.1%) patients in the Combined group and in 14 (25.4%) patients in the Control group (OR 0.29, 95% CI [0.09-0.88]).

A combined strategy of device-based CM reduction plus UFR-guided hydration is superior to operator-dependent CM sparing strategies plus UFR-guided hydration in preventing CA-AKI in high-risk patient.

We aimed to evaluate the frequency of contrast induced nephropathy (CIN), its relationship with accepted risk factors and long-term renal outcomes in patients who underwent coronary angiography (CAG).

All patients who underwent CAG between April 2020 and April 2021 were retrospectively evaluated. CIN was defined as characteristic increase in serum creatinine after CAG.

CIN developed in 50 (5.4%) of 934 patients. The CIN rate was found to be statistically significantly higher in patients with diabetes, hypertension, heart failure and those using diuretics. Pre-procedural hemoglobin, albumin and GFR were found to be independent risk factors for CIN. After discharge, the urea and creatinine values of the patients who developed CIN were significantly higher than those who did not.

We concluded that in order to reduce the development of CIN, hemoglobin and albumin levels should be evaluated with renal functions before the procedure and they should be kept within normal limits.

Heart failure with preserved ejection fraction (HFpEF) is inherently a complex inflammatory syndrome, and heightened inflammation is strongly associated with an increased risk of death. However, the association of systemic inflammation levels with total and cardiovascular death among patients with HFpEF remains unknown. We aimed to investigate the prognostic impact of systemic inflammation on all-cause and cardiovascular death among patients with HFpEF.

Patients with HFpEF were included in this study. Systemic inflammation response index (SIRI) is defined as the multiplication of neutrophil and monocyte divided by lymphocyte count, and patients were divided into four groups based on SIRI quartiles. Cox regression models and competing risk models were used to examine the relationships between SIRI and total and cardiovascular‑specific mortality, respectively.

9,986 patients with HFpEF were included in five tertiary hospitals. During a median follow-up period of 4.4 years, a total of 2004 patients died, of which 965 were cardiovascular deaths. After fully adjusting for confounders, elevated SIRI level was significantly related to the increased risk of all-cause death (Q2, Q3, Q4: adjusted hazard ratio (aHR) [95 confidence interval (CI)%] =1.17[1.01-1.35], 1.31[1.13-1.52], 1.51[1.30-1.76], respectively; P for trend <0.001). The elevated quartile of SIRI showed higher risks of cardiovascular death, but there was no statistically significant increased risk of cardiovascular death across the lower SIRI quartile (model 3: Q2, Q3, Q4: aHR [95CI%] =1.22[0.99-1.51], 1.50[1.20-1.86], 1.73[1.37-2.18], respectively; P for trend <0.001).

Elevated systemic inflammation level on admission was correlated with an increased risk of all-cause and cardiovascular death among patients with HFpEF. The SIRI may serve as a promising marker of risk stratification for patients with HFpEF.

Coronary angiography and percutaneous coronary intervention (PCI) in patients with chronic kidney disease (CKD) is associated with increased risk of contrast induced nephropathy (CIN) and requirement for renal replacement therapy (RRT).

We aimed to evaluate our single center experience of ultra-low contrast PCI in patients with CKD and to characterize 1 year outcomes.

We performed a retrospective analysis of ultra-low contrast PCI at our institution between 2016 and 2022. Patients with CKD3b-5 (eGFR <45 mL/min/1.73m2), not on RRT who underwent ultra-low contrast PCI ( < 30 mL of contrast during PCI) were included. Primary outcomes included change in eGFR post-procedurally, and death, RRT requirement, and major adverse cardiac events (MACE) at 1 year follow-up.

One hundred patients were included in the study. The median age was 67 years old and 28% were female. The median baseline eGFR was 21.5 mL/min/1.73m2 (IQR 14.08-32.0 mL/min/1.73m2). A median of 8.0 mL (IQR 0-15 mL) of contrast was used during PCI. Median contrast use to eGFR ratio was 0.37 (IQR 0-0.59). There was no significant difference between pre-and postprocedure eGFR (p = 0.84). At 1 year, 8% of patients died, 11% required RRT and 33% experienced MACE. The average time of RRT initiation was 7 months post-PCI. Forty-four patients were undergoing renal transplant evaluation, of which 17 (39%) received a transplant.

In patients with advanced CKD, ultra-low contrast PCI is feasible and safe with minimal need for peri-procedural RRT. Moreover, ultra-low contrast PCI may allow for preservation of renal function in anticipation of renal transplantation.

Introduction Contrast-induced nephropathy (CIN) is a serious risk involved in computed tomography (CT) scans, particularly for older people. The main idea of this clinical audit was to assess current practices regarding renal function tests (RFTs) and hydration status before and after contrast CT scans in older patients at District Headquarters Hospital (DHQ), Dera Ismail Khan, Pakistan, and to implement recommendations for improvement. CIN is a form of acute kidney injury that occurs after the administration of contrast dye used in imaging procedures and is characterized by a sudden deterioration in renal functions. Methods This clinical audit checked adherence to renal protection protocols in elderly patients undergoing contrast CT scans. Conducted over three cycles from July 5 to August 15, 2022, this clinical audit included 30 patients aged 75 and above. Each cycle had 10 patients, divided equally between males and females, and further categorized into age groups of 75-85 years and 86-95 years. Data collection involved reviewing patient files, medication charts, and CT scan reports. Compliance with RFT documentation and hydration before and after the CT scan was assessed against the standards set by Basildon and Thurrock University Hospitals NHS Foundation Trust. Data were analyzed using Microsoft Excel 2023 (Microsoft® Corp., Redmond, WA), and graphs were created using Microsoft Word 2023 (Microsoft® Corp., Redmond, WA). Results The mean age ± standard deviation (SD) for males was 81.8 ± 5.01 in the first cycle, 83.4 ± 6.46 in the second cycle, and 82.4 ± 4.72 in the third cycle. For females, the mean age ± SD was 83.2 ± 5.80 in the first cycle, 85.2 ± 6.41 in the second cycle, and 83.0 ± 6.12 in the third cycle. The first audit cycle revealed that, while all patients (100%) had their RFTs documented before the CT scan, only 20% were adequately hydrated pre-scan, and none (0%) had RFTs performed post scan. Post-scan hydration was also low at 20%. These findings highlighted gaps in adherence to renal protection protocols. The second cycle showed improvements, with pre-scan hydration adherence increasing to 80%, post-scan RFTs to 60%, and post-scan hydration to 70%. By the third cycle, full compliance (100%) was achieved across all standards, including pre- and post-scan renal functions test and hydration. Conclusion The clinical audit at District Headquarters Hospital, Dera Ismail Khan, addressed gaps in renal protection protocols for elderly patients undergoing contrast CT scans. The audit improved adherence over three cycles through targeted interventions, including staff training, implementation of checklists, patient education, modifying the reporting format, and providing instructions in the local language. It also highlighted the importance of continuous education and regular monitoring. The clinical audit would be expanded to another hospital within the medical teaching institute, Dera Ismail Khan. This measure will maintain and enhance patient care, prevent CIN, and improve the renal health of elderly patients.

Limited evidence exists regarding the clinical baseline characteristics at admission for acute kidney injury (AKI) before and after interventional cardiac procedures (ICP) in elderly patients with coronary artery disease (CAD).

A total of 488 elderly patients were enrolled in this retrospective single-center study conducted from January 2019 to July 2022, and a classification and regression tree (CART) analysis was performed to identify the high-risk population.

The AKI incidence was 21.1 % (103/488) in this study, with 27 and 76 individuals developing AKI before and after ICP, respectively. CART analysis revealed that exposure to nephrotoxic drugs and diuretics had the strongest predictive capacities for identifying patients at risk of developing pre-ICP AKI, with the incidence among these high-risk patients ranging from 6.5 % to 13.8 %. Meanwhile, the optimum discriminators for identifying those at high risk of post-ICP AKI were the administration of diuretics, D-value ≤ -860 mL, age >73 years, and administration of nephrotoxic drugs, and the latter model predicted that the AKI incidence among high-risk patients was between 50.0 % and 60.0 %.

Elderly patients with CAD exhibited an elevated incidence of AKI. CART models suggested that exposure to nephrotoxic drugs and diuretics, D-value, and age were significantly associated with AKI in the elderly with CAD. Importantly, these baseline characteristics at admission could be utilized to identify elderly patients at high risk of pre- and post-ICP AKI.

The objective of this study is to investigate the occurrence and factors that influence the development of contrast-induced nephropathy (CIN) in high-risk patients undergoing angioplasty and to evaluate the effectiveness of the Mehran risk score in predicting CIN among this patient population.

This prospective, observational study enrolled patients undergoing elective coronary angiography or a percutaneous coronary intervention (PCI) procedure. The patients were stratified into four risk groups based on the Mehran risk score, a validated tool for predicting the risk of CIN. Univariate and multivariate analyses were conducted to evaluate the risk factors associated with the development of CIN. A p-value of <0.05 was considered to indicate statistical significance.

During the study period, a total of 55 high-risk patients underwent PCI. The incidence of CIN was 25.5% (n=14). Univariate and multivariate analyses revealed that age >75 years and estimated glomerular filtration rate (eGFR) <60 (p<0.05) were independently associated with a significantly increased risk of developing CIN. A considerable proportion of patients (23; 41.8%) in the study were categorized as having an intermediate risk for CIN based on the Mehran risk score.

This study observed a high incidence of CIN and encourages the use of predictive tools like the Mehran risk score to assess the risk of CIN occurrence, with age over 70 years and eGFR less than 60 emerging as significant.

This study aimed to investigate the efficacy of a pre-procedural white blood cell (WBC) count in the prediction of contrast-induced acute kidney injury (CI-AKI) risk in coronary artery disease patients receiving a percutaneous coronary intervention (PCI). This observational study comprises a sample of 1,013 coronary artery disease patients (including ACS and stable angina) receiving PCI, gathered from September 2015 to July 2017. CI-AKI incidence in the study population was 4.8% (49/1013). Patients in the CI-AKI group had significantly higher WBC counts than those in the non-CI-AKI group (10.41 ± 5.37 vs. 8.09 ± 3.10, p = 0.004). Logistic analysis showed that WBC count (odds ratio [OR]: 1.12, 95% CI [1.03-1.21], P = 0.006) was a significant and independent predictor of CI-AKI risk in patients receiving PCI, Receiver-operating characteristic (ROC) curve analysis found that pre-procedural WBC count ≥11.03*109/L was the optimal cut-off value in the prediction of CI-AKI risk with a sensitivity of 41.0% and a specificity of 86.5%. Patients with CI-AKI had a significantly worse 1-year survival rate than patients without CI-AKI (91.8% vs. 97.6%, P = 0.012). In summary, increased pre-procedural WBC count is associated with an increased risk of developing CI-AKI in patients receiving PCI.

Contrast-induced acute kidney injury (CI-AKI) is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality. Its pathophysiology, although not well-established, revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney. Critically ill patients, as well as those with pre-existing renal disease and cardiovascular comorbidities, are more susceptible to CI-AKI. Despite the continuous research in the field of CI-AKI prevention, clinical practice is based mostly on periprocedural hydration. In this review, all the investigated methods of prevention are presented, with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

Ultra-low contrast administration during coronary angiography has been previously shown to be feasible and safe among patients with stable chronic kidney disease. In the present study, we investigate the safety of ultra-low contrast coronary angiography in patients with pre-existing acute kidney injury (AKI).

The study was a retrospective single-center evaluation of hospitalized patients who had AKI and required coronary angiography. Ultra-low contrast use was defined as ≤18 mL of contrast media.

The cohort consisted of a case series of eight inpatients with AKI who required coronary angiography. The mean age was 57 (±16) years and half were females. All patients had chronic kidney disease with a mean baseline estimated glomerular filtration rate of 34 (±17) mL/min/1.73 m2. The mean creatinine before angiography was 3 (±1) mg/dL and volume of contrast administered was 14 (±4) mL. One patient had a 0.1 mg/dL increase in creatinine during admission, and no patients had further AKI up to 1-week postprocedure.

The current data suggest that ultra-low contrast coronary angiography can be safely performed in patients with pre-existing AKI The study should be viewed as hypothesis-generating due to its small sample size. A larger cohort is required to validate the results.

Contrast-induced nephropathy (CIN) is a form of acute kidney injury (AKI) occurring in patients undergoing cardiac catheterization, such as coronary angiography (CAG) or percutaneous coronary intervention (PCI). Although the conventional criterion for CIN detection involves a rise in creatinine levels within 72 h after contrast media injection, several limitations exist in this definition. Up to now, various meta-analyses have been undertaken to assess the accuracy of different biomarkers of CIN prediction. However, the existing body of research lacks a cohesive overview. To address this gap, a comprehensive umbrella review was necessary to consolidate and summarize the outcomes of prior meta-analyses. This umbrella study aimed to offer a current, evidence-based understanding of the prognostic value of biomarkers in predicting CIN.

A systematic search of international databases, including PubMed, Scopus, and Web of Science, from inception to December 12, 2023, was conducted to identify meta-analyses assessing biomarkers for CIN prediction. Our own meta-analysis was performed by extracting data from the included studies. Sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio were assessed using Meta-Disc and CMA softwares.

Twelve studies were ultimately included in the umbrella review. The results revealed that neutrophil gelatinase-associated lipocalin (NGAL) exhibited the highest area under the curve (AUC), followed by cystatin-C, urinary kidney injury molecule-1 (uKIM-1), and brain natriuretic peptide (BNP) with AUCs of 0.91, 0.89, 0.85, and 0.80, respectively. NGAL also demonstrated the highest positive likelihood ratio [effect size (ES): 6.02, 95% CI 3.86-9.40], followed by cystatin-C, uKIM-1, and BNP [ES: 4.35 (95% CI 2.85-6.65), 3.58 (95% CI 2.75-4.66), and 2.85 (95% CI 2.13-3.82), respectively]. uKIM-1 and cystatin-C had the lowest negative likelihood ratio, followed by NGAL and BNP [ES: 0.25 (95% CI 0.17-0.37), ES: 0.25 (95% CI 0.13-0.50), ES: 0.26 (95% CI 0.17-0.41), and ES: 0.39 (0.28-0.53) respectively]. NGAL emerged as the biomarker with the highest diagnostic odds ratio for CIN, followed by cystatin-C, uKIM-1, BNP, gamma-glutamyl transferase, hypoalbuminemia, contrast media volume to creatinine clearance ratio, preprocedural hyperglycemia, red cell distribution width (RDW), hyperuricemia, neutrophil-to-lymphocyte ratio, C-reactive protein (CRP), high-sensitivity CRP, and low hematocrit (P < 0.05).

NGAL demonstrated superior diagnostic performance, exhibiting the highest AUC, positive likelihood ratio, and diagnostic odds ratio among biomarkers for CIN, followed by cystatin-C, and uKIM-1. These findings underscore the potential clinical utility of NGAL, cystatin-C and uKIM-1 in predicting and assessing CIN.

This study aimed to explore the association of preoperative neutrophil percentage (NEUT%) with the risk of acute kidney injury (AKI) in patients with acute myocardial infarction (AMI) having undergone coronary interventional therapy.

A single-center, retrospective and observational study was conducted. From December 2012 to June 2021, patients with AMI were enrolled and divided into AKI group and non-AKI group. The NEUT% in the two groups was compared. The association between NEUT% with the risk of post-AMI AKI was analyzed by univariate and multivariable logistic regression. Kaplan-Meier survival curve was drawn to evaluate the prognostic ability of NEUT% for short-term all-cause death following AMI.

A total of 3001 consecutive patients were enrolled with an average age of 64.38 years. AKI occurred in 327 (10.9%) patients. The NEUT% was higher in the AKI group than in the non-AKI group ([76.65±11.43]% versus [73.22±11.83]%, P<0.001). NEUT% was also identified as an independent risk factor for AKI in AMI patients after adjustment (OR=1.021, 95% CI: 1.010-1.033, P < 0.001). Compared with those at the lowest quartile of NEUT%, the patients at quartiles 2-4 had a higher risk of AKI (P for trend = 0.003). The odds of AKI increased by 29.0% as NEUT% increased by 1 standard deviation (OR=1.290, 95% CI: 1.087-1.531, P = 0.004). After a median of 35 days follow-up, 93 patients died. Patients with a higher NEUT% presented a higher risk of all-cause death after AMI (Log rank: χ2 =24.753, P<0.001).

In AMI patients, the peripheral blood NEUT% was positively associated with the odds of AKI and short-term all-cause mortality. NEUT% may provide physicians with more information about disease development and prognosis.

Contrast-induced nephropathy (CIN) or contrast-induced acute kidney injury (CI-AKI) refers to an acute kidney injury (AKI) occurring after exposure to contrast media, commonly used in diagnostic procedures or therapeutic angiographic interventions. Recently, Na/K citrate, used for urine alkalinization, has been assessed for preventing CIN. This experiment evaluated Na/K citrate's efficacy in preventing CIN in high-risk patients undergoing cardiac catheterization.

A prospective randomized clinical trial involved 400 patients with moderate- to high-risk factors for CIN undergoing elective percutaneous coronary intervention (PCI). They were randomly assigned to either the control or Na/K citrate groups. The Na/K citrate group (n = 200) received a 5 g Na/K citrate solution diluted in 200 mL water 2 hours before and 4 hours after the first administration, along with intravenous hydration for 2 hours before and 6 hours after the procedure. In contrast, the control group (n = 200) received only intravenous hydration. Serum creatinine (SCr) levels were measured before contrast exposure and 48 hours afterward. CIN was defined as a 25% increase in serum creatinine (SCr) or > 0.5 mg/dL 48 hours after contrast administration. The significance level was set at P ˂ 0.05.

CIN was observed in 33 patients (16.5%) in the control group and 6 patients (3%) in the Na/K citrate group. The incidence of CIN was found to have a significant difference between the 2 groups 48 hours after receiving the radiocontrast agent (P < 0.001).

Our results show that Na/K citrate is helpful and substantially reduces the incidence of CIN.

The estimated glomerular filtration rate (eGFR) based on creatinine is crucial for the risk assessment of contrast-associated acute kidney injury (CA-AKI). In recent, the difference between cystatin C-based eGFR (eGFRcys) and creatinine-based eGFR (eGFRcr) has been widely documented. We aimed to explore whether intraindividual differences between eGFRcys and eGFRcr had potential value for CA-AKI risk assessment in patients undergoing elective percutaneous coronary intervention (PCI).

From January 2012 to December 2018, we retrospectively observed 5049 patients receiving elective PCI. To determine eGFR, serum creatinine and cystatin C levels were measured. CA-AKI was defined as serum creatinine being increased ≥ 50% or 0.3 mg/dL within 48 h after contrast agents exposure. Chronic kidney disease (CKD) was defined as the eGFR < 60 mL/min/1.73 m2.

Approximately half of the participants (2479, 49.1%) had a baseline eGFRdiff (eGFRcys-eGFRcr) between -15 and 15 mL/min/1.73 m2. Restricted cubic splines analysis revealed a nonlinear relationship between eGFRdiff and CA-AKI. Multivariable logistic regression analysis indicated that compared with the reference group (-15 to 15 mL/min/1.73 m2), the negative-eGFRdiff group (less than -15 mL/min/1.73 m2) had a higher risk of CA-AKI (OR, 3.44; 95% CI, 2.57-4.64). Furthermore, patients were divided into four groups based on CKD identified by eGFRcys or eGFRcr. Multivariable logistic analysis revealed that patients with either CKDcys (OR, 2.94; 95% CI, 2.19-3.95, P < 0.001) or CKDcr (OR, 2.44; 95% CI, 1.19-4.63, P < 0.001) had an elevated risk of CA-AKI compared to those without CKDcys and CKDcr.

There are frequent intraindividual differences between eGFRcys and eGFRcr, and these differences can be used to forecast the risk of CA-AKI.

Contrast-associated acute kidney injury (CA-AKI) is a prevalent complication following coronary angiography (CAG). However, there is ongoing controversy surrounding its precise definition. Although previous studies have demonstrated the successful application of appropriate definitions in managing high-risk CA-AKI patients, there remains limited research on the association between different definitions and prognosis specifically in patients with chronic kidney disease (CKD).

A total of 4197 CKD patients undergoing coronary angiography (CAG) were included in this study. Two definitions of contrast-associated acute kidney injury (CA-AKI) were used: CA-AKIA, which was defined as an increase of ≥0.5 mg/dL or >25% in serum creatinine (SCr) from baseline within 72 hours after CAG, and CA-AKIB, which was defined as an increase of ≥0.3 mg/dL or >50% in SCr from baseline within 48 hours after CAG. Cox regression analysis was employed to assess the association between these two definitions and long-term mortality. Additionally, population attributable risks (PARs) were calculated to evaluate the impact of CA-AKI definitions on long-term prognosis.

During the median follow-up period of 4.70 (2.50-7.78) years, the overall long-term mortality was 23.6%, and the long-term mortality in patients with CA-AKI according to both CA-AKIA and CA-AKIB criteria were 33.5% and 33.8%, respectively. We found that CA-AKIA (HR: 1.45, 95% CI: 1.23-1.70, p<0.001) and CA-AKIB (HR: 1.44, 95% CI: 1.23-1.69, p<0.001) were associated with long-term mortality. The PARs were the highest for CA-AKIA (5.87%), followed by CA-AKIB (5.70%).

Contrast-associated acute kidney injury (CA-AKI) is a frequently observed complication in CKD patients undergoing coronary angiography (CAG), and both definitions of CA-AKI are significantly correlated with a poor long-term prognosis. Consequently, in the clinical management of CKD patients, it is crucial to prioritize CA-AKI, irrespective of the specific CA-AKI definition used.

Chronic kidney disease (CKD) is associated with a high burden of coronary artery disease (CAD), which remains the leading cause of death in CKD patients. Despite the high cardiovascular risk, ACS patients with renal dysfunction are less commonly treated with guideline-based medical therapy and are less frequently referred for coronary revascularization.

The management of CAD is more challenging in patients with CKD than in the general population due to concerns regarding side effects and renal toxicity, as well as uncertainty regarding clinical benefit of guideline-based medical therapy and interventions. Patients with advanced CKD and especially those receiving dialysis have not traditionally been represented in randomized trials evaluating either medical or revascularization therapies. Thus, only scant data from small prospective studies or retrospective analyses are available. Recently published studies suggest that there are significant opportunities to substantially improve both cardiovascular and renal outcomes of patients with CAD and CKD, including new medications and interventions. Thus, the objective of this review is to summarize the current evidence regarding the management of CAD in CKD patients, in particular with respect to improvement of both cardiovascular and renal outcomes.

Adequate medical therapy and coronary interventions using evidence-based strategies can improve both cardiac and renal outcomes in patients with CAD and CKD.

Background Contrast-induced nephropathy (CIN) significantly complicates percutaneous coronary intervention (PCI), with a higher prevalence in diabetic patients. This study compares the incidence of CIN in diabetic and non-diabetic patients undergoing PCI. Material and methods Conducted at Lady Reading Hospital, Peshawar, PAK, from January to December 2023, this observational study involved 450 adult patients with coronary artery disease (CAD) undergoing PCI. The cohort was categorized based on diabetes status, excluding patients with chronic kidney disease and those on renal replacement therapy. Baseline characteristics documented included age, gender, blood pressure, creatinine levels, and the presence of acute coronary syndrome (ACS). CIN was defined as a ≥25% increase in serum creatinine from baseline within 48-72 hours post-PCI. Data analysis was performed using the Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 25.0, Armonk, NY), incorporating descriptive statistics, Chi-square tests, and independent t-tests, with a significance level of p<0.05. Results The median age of the study population was 55 years. The cohort comprised 52% male (n=234) and 48% female (n=216). Notably, 33% (n=149) had ACS. Diabetic patients exhibited a significantly higher incidence of CIN post-PCI compared to non-diabetics. The highest incidence of CIN (17%, n=77) occurred in the 70+ age group. The findings highlight the criticality of renal function monitoring and procedural adjustments for diabetic patients. Conclusion Diabetic patients demonstrate an increased risk of CIN following PCI. This necessitates the development of tailored prevention strategies for this high-risk subgroup.

Radiological and interventional cardiology procedures are in continuous expansion, leading to an important increase in the incidence of contrast-associated acute kidney injury (CA-AKI). Although numerous methods of CA-AKI prevention have been studied, at present, there is no consensus on the definition of this entity or on its prevention. In this paper, we aim to provide a critical analysis of the existing data on the epidemiology, pathophysiology, and clinical significance of CA-AKI. Existing and emergent approaches for CA-AKI prevention are also discussed, with a focus on parenteral fluid administration and on the most recent clinical and experimental data. We also emphasize a number of questions that remain to be answered, and we identify hotspots for future research.

Contrast-induced-acute kidney injury (CI-AKI) is a potential complication of angiographic procedures. The DyeVert Contrast Reduction system (Osprey Medical, United States) is a device to reduce the concentration of contrast medium (CM) in the kidneys by decreasing the amount of CM delivered to patients. Unlike manual systems, few data are available on the DyeVert Power XT system, which is used in conjunction with automated contrast injection. The main aim of our study was to evaluate its effectiveness during percutaneous coronary interventions (PCI).

Between 2020 and 2022, 101 patients who underwent PCI with the DyeVert Power XT system (case group) were enrolled to evaluate the amount of CM saved through the use of this device, as well as the rate, severity, and predictors of CI-AKI. Patients who underwent PCI without the use of the device (control group) were enrolled to create a matched group allowing assessment of differences in CM and the CI-AKI rate.

In the case group, the amount of CM saved was 114 ± 42 mL, representing an average of 32% of the total CM. Fourteen patients (13.9%) developed CI-AKI. The only independent predictors of CI-AKI were hematocrit (OR, 0.86; 95%CI, 0.74-0.99; P = .04) and ejection fraction (OR, 0.88; 95%CI, 0.82-0.95; P = .001). As a result of diversion by the device, the amount of CM delivered was lower in the case group than in controls (252 vs 267 mL; P = .42), but this difference was nonsignificant. Equally, the reduction in CI-AKI (14.3% vs 16.3%) was nonsignificant.

Hematocrit and ejection fraction may be more important predictors of CI-AKI than the CM volume normally used during PCI in the general population. The net practical benefit of DyeVert Power XT was low.

The association between uric acid (UA) and contrast-induced acute kidney injury (CI-AKI) following coronary angiography (CAG) has been established. However, whether the association would vary with age remained undetermined.

We performed the retrospective analysis based on the Cardio-renal Improvement II study, (ClinicalTrials.gov NCT05050877), which enrolled consecutive patients undergoing coronary angiography in 5 teaching hospitals in China from 2007 to 2020. The primary outcome was CI-AKI defined as the rise of serum creatinine (SCr) ≥ 0.5 mg/dL or 25% compared with the baseline value within 48 hours following CAG. The effect of age on the association between uric acid and CI-AKI was assessed by the logistic regression model.

A total of 36,550 patients (mean age 63.08±5.6-year-old, 41.7% men) were included in the study. After adjusting for the confounders, the risk of CI-AKI between each quartile of uric acid was insignificant in the young group. In patients of the middle group, lower UA was associated with a lower risk of CI-AKI while higher UA was associated with a higher risk (Q1 OR: 0.853, 95% CI: 0.734-0.993; Q4 OR: 1.797, 95% CI: 1.547-2.09). In patients of the elder group, lower and higher UA were both associated with a higher risk of CI-AKI (Q1 OR: 1.247, 95% CI: 1.003-1.553; Q4 OR: 1.688, 95% CI: 1.344-2.124). The restricted cubic spline indicated a non-linear association between UA and CI-AKI in middle and elder age groups but a linear association in the young age group.

The association between uric acid and CI-AKI vary in patients of different age. Patients with elder age should maintain a middle level of uric acid while patients with middle age should consider a lower level of uric acid to reduce the risk of CI-AKI. The level of UA was an insignificant risk factor for CI-AKI in young patients.