Coarctation of the aorta (CoA) often leads to hypertension posttreatment. Evidence is lacking for the current >20 mm Hg peak-to-peak blood pressure (BP) gradient (BPGpp) guideline, which can cause aortic thickening, stiffening, and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model and test if predictors translate to hypertension status in patients with CoA.

Rabbits (n=75; 5-12/group) were exposed to mild, intermediate, or severe CoA (≤12, 13-19, ≥20 mm Hg BPGpp) for ≈1, 3, or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction, and endothelial function evaluated via multivariate regression. Relevance to patients with CoA (n=239; age, 0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) versus follow-up hypertension status.

CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and hypertension in patients with CoA. Interaction between patient age and BPGpp at surgery contributed significantly to hypertension, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that preoperative BPGpp and surgical age predict risk of hypertension along with residual postoperative BPGpp.

These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of hypertension.

Systemic hypertension has been considered mainly as an adult health issue for a long time, but it is now being increasingly acknowledged as a significant problem also among pediatric patients. The frequency of pediatric hypertension has grown mostly because of increases in childhood obesity and sedentary lifestyles, but secondary forms of hypertension play a role as well. Considering that unaddressed hypertension during childhood can result in enduring cardiovascular complications, timely identification and intervention are essential. Strategies for addressing this disease encompass not only lifestyle adjustments, but also the use of medications when needed. Lifestyle modifications entail encouraging a nutritious diet, consistent physical activity, and the maintenance of a healthy weight. Moreover, educating both children and their caregivers about monitoring blood pressure at home can aid in long-term management. Thus, the aim of this review is to discuss the etiologies, classification, and principles of the treatment of hypertension in pediatric patients.

Coarctation of the aorta (CoA) often leads to hypertension (HTN) post-treatment. Evidence is lacking for the current >20 mmHg peak-to-peak blood pressure gradient (BPGpp) guideline, which can cause aortic thickening, stiffening and dysfunction. This study sought to find the BPGpp severity and duration that avoid persistent dysfunction in a preclinical model, and test if predictors translate to HTN status in CoA patients.

Rabbits (N=75; 5-12/group) were exposed to mild, intermediate or severe CoA (≤12, 13-19, ≥20 mmHg BPGpp) for ~1, 3 or 22 weeks using dissolvable and permanent sutures with thickening, stiffening, contraction and endothelial function evaluated via multivariate regression. Relevance to CoA patients (N=239; age=0.01-46 years; median 3.7 months) was tested by retrospective review of predictors (preoperative BPGpp, surgical age, etc.) vs follow-up HTN status.

CoA duration and severity were predictive of aortic remodeling and active dysfunction in rabbits, and HTN in CoA patients. Interaction between patient age and BPGpp at surgery contributed significantly to HTN, similar to rabbits, suggesting preclinical findings translate to patients. Machine learning decision tree analysis uncovered that pre-operative BPGpp and surgical age predict risk of HTN along with residual post-operative BPGpp.

These findings suggest the current BPGpp threshold determined decades ago is likely too high to prevent adverse coarctation-induced aortic remodeling. The results and decision tree analysis provide a foundation for revising CoA treatment guidelines considering the interaction between CoA severity and duration to limit the risk of HTN.

While coarctation of the aorta varies greatly in both severity and age at presentation, all patients are at increased risk of hypertension both before and after repair. Despite advances in knowledge about genetic etiologies, pathophysiologic mechanisms, and optimal repair strategies, patients with repaired coarctation of the aorta remain at increased risk of acquired cardiovascular disease. The aims of this review are to describe the management of coarctation of the aorta at all ages before and after repair, highlight pathophysiologic mechanisms of hypertension, and review long-term follow-up considerations.

Long-term effects of systemic hypertension (HTN) and HTN-mediated damages have been largely studied in non-congenital adult populations. By contrast, robust data about the predisposing factors, prevalence, consequences, and treatment of HTN in adults with congenital heart diseases (ACHD) is still scarce. Different mechanisms including the underlying cardiac disease, cardiac surgery and its consequences, the development of metabolic syndrome and secondary forms seem to play a role in HTN in ACHDs. To mitigate the potential long-term effects of HTN in this complex population, a meticulous follow-up is mandatory to identify patients who should receive treatment, and tailored strategies should be applied to obtain the best as possible result. Thus, this review will investigate risk factors, effects, and treatments of HTN in ACHD patients.

In adults with congenital heart disease (ACHD), conditions acquired with aging, such as metabolic syndrome, hypertension, diabetes mellitus, and obesity, can negatively influence the original cardiovascular disease. Metabolic syndrome has a higher prevalence in ACHD than in the general population. In contrast, coronary artery disease shows a similar prevalence in adults with acyanotic CHD and the general population, while adults with cyanotic CHD, even after repair, have an even lower incidence of coronary artery disease than the general population/adults with acyanotic CHD. However, even in those with cyanotic CHD, coronary artery disease can develop when they have risk factors such as obesity, dyslipidemia, hypertension, diabetes mellitus, smoking habit, or limited exercise. The prevalence of risk factors for cardiovascular disease is similar between ACHD and the general population, but an increased risk of coronary atherosclerosis has been observed for congenital coronary artery anomalies, dextro-transposition of the great arteries after arterial switch operation, Ross procedure, and coarctation of the aorta. Aortopathy may be an additional risk factor for cardiovascular disease. As ACHD have other abnormalities that may make the heart more vulnerable to both the development of atherosclerosis and adverse cardiovascular sequelae, regular evaluation of their cardiovascular disease risk status is recommended. Metabolic syndrome is more common among ACHD than in the general population, and may therefore increase the future incidence of atherosclerotic coronary artery disease even in ACHD. Thus, ACHD should be screened for metabolic syndrome to eliminate risk factors for atherosclerotic coronary artery disease.

Coarctation of the aorta (CoA) is a relatively common congenital cardiac defect often causing few symptoms and therefore can be challenging to diagnose. The hallmark finding on physical examination is upper extremity hypertension, and for this reason, CoA should be considered in any young hypertensive patient, justifying measurement of lower extremity blood pressure at least once in these individuals. The presence of a significant pressure gradient between the arms and legs is highly suggestive of the diagnosis. Early diagnosis and treatment are important as long-term data consistently demonstrate that patients with CoA have a reduced life expectancy and increased risk of cardiovascular complications. Surgical repair has traditionally been the mainstay of therapy for correction, although advances in endovascular technology with covered stents or stent grafts permit nonsurgical approaches for the management of older children and adults with native CoA and complications. Persistent hypertension and vascular dysfunction can lead to an increased risk of coronary disease, which, remains the greatest cause of long-term mortality. Thus, blood pressure control and periodic reassessment with transthoracic echocardiography and three-dimensional imaging (computed tomography or cardiac magnetic resonance) for should be performed regularly as cardiovascular complications may occur decades after the intervention.

In adult congenital heart disease (ACHD), residua and sequellae after initial repair develop late complications such as cardiac failure, arrhythmias, thrombosis, aortopathy, pulmonary hypertension and others. Acquired lesions with aging such as hypertension, diabetes mellitus, obesity can be negative influence on original cardiovascular disease (CVD). Also, atherosclerosis may pose an additional health problem to ACHD when they grow older and reach the age at which atherosclerosis becomes clinically relevant. In spite of the theoretical risk of atherosclerosis in ACHD due to above mentioned factors, cyanotic ACHDs even after repair are noted to have minimal incidence of coronary artery disease (CAD). Acyanotic ACHD has similar prevalence of CAD as the general population. However, even in cyanotic ACHD, CAD can develop when they have several risk factors for CAD. The prevalence of risk factor is similar between ACHD and the general population. Risk of premature atherosclerotic CVD in ACHD is based, 3 principal mechanisms: lesions with coronary artery abnormalities, obstructive lesions of left ventricle and aorta such as coarctation of the aorta and aortopathy. Coronary artery abnormalities are directly affected or altered surgically, such as arterial switch in transposition patients, may confer greater risk for premature atherosclerotic CAD. Metabolic syndrome is more common among ACHD than in the general population, and possibly increases the incidence of atherosclerotic CAD even in ACHD in future. Thus, ACHD should be screened for metabolic syndrome and eliminating risk factors for atherosclerotic CAD.

The aim of this study is to address the presence of hypertension and risk for cardiovascular diseases in patients with Coarctation of the Aorta (CoA) who were treated with endovascular stent placement.

Twenty patients (mean age: 14.2 ± 3.9 years) who were treated with stent and 20 age- and sex-matched controls were included to the study. Structure and functions of left ventricle were assessed by echocardiography. Carotid intima media (CIM) thickness was measured by using sonography as a marker for detecting cardiovascular risk. As indirect marker of arterial stiffness, pulse wave velocity, and augmentation index were recorded by ambulatory blood pressure monitorization/arteriography device.

By ambulatory blood pressure monitorization, 24 h and daytime systolic and mean arterial pressure values were found to be significantly higher in patient group. Based on percentile values, 15% and 5% of patients were pre-hypertensive and hypertensive, respectively. Pulse wave velocity and cardiac output values were found to be significantly higher than control group. CIM thickness was also found to be significantly higher in patient group when compared to controls.

It was shown that hypertension incidence as demonstrated by ambulatory blood pressure monitorization and risk for cardiovascular diseases as indicated by CIM thickness and Pulse wave velocity were higher than those in healthy population even after CoA is corrected.

Survival into adult life in patients with aortic coarctation is typical following surgical and catheter-based techniques to relieve obstruction. Late sequelae are recognised, including stroke, hypertension, and intracerebral aneurysm formation, with the underlying mechanisms being unclear. We hypothesised that patients with a history of aortic coarctation may have abnormalities of cerebral blood flow compared with controls.

Patients with a history of aortic coarctation underwent assessment of cerebral vascular function. Vascular responsiveness of intracranial vessels to hypercapnia and degree of cerebral artery stiffness using Doppler-derived pulsatility indices were used. Response to photic stimuli was used to assess neurovascular coupling, which reflects endothelial function in response to neuronal activation. Patient results were compared with age- and sex-matched controls.

A total of 13 adult patients (males=10; 77%) along with 13 controls underwent evaluation. The mean age was 36.1±3.7 years in the patient group. Patients with a background of aortic coarctation were noted to have increased pulse pressure on blood pressure assessment at baseline with increased intracranial artery stiffness compared with controls. Patients with a history of aortic coarctation had less reactive cerebral vasculature to hypercapnic stimuli and impaired neurovascular coupling compared with controls.

Adult patients with aortic coarctation had increased intracranial artery stiffness compared with controls, in addition to cerebral vasculature showing less responsiveness to hypercapnic and photic stimuli. Further studies are required to assess the aetiology and consequences of these documented abnormalities in cerebral blood flow in terms of stroke risk, cerebral aneurysm formation, and cognitive dysfunction.

Twin survivors of twin-twin transfusion syndrome (TTTS) may be at risk for early onset of cardiovascular disease. The aim of this study was to determine prevalence and risk factors for elevated blood pressure (BP) among children treated with selective laser photocoagulation of communicating vessels.

Data were prospectively collected from surviving children treated for TTTS with laser surgery from 2008 through 2010. Systolic BP (SBP) and diastolic BP (DBP) were obtained from 91 child survivors at age 24 months (±6 weeks) and evaluated based on age, sex, and height percentile. BP percentiles were calculated for each patient and categorized as normal (<95%) or abnormal (>95%). Clinical variables were evaluated using multilevel regression models to evaluate risk factors for elevated BP.

BP was categorized as normal in 38% and abnormal in 62% of twin survivors based on percentile for sex, age, and height; a comparable distribution was found for DBP elevation. There were no differences between donor and recipient twins for absolute SBP and DBP or BP classification. In a multivariate analysis, significant risk factors for higher SBP included prematurity (β -0.54; 95% confidence interval [CI], -0.99 to -0.09; P = .02), higher weight percentile (β 0.24; 95% CI, 0.05-0.42; P = .01), and presence of cardiac disease (β 0.50; 95% CI, 0.10-0.89; P = .01). Prematurity was also a significant risk for abnormal DBP (odds ratio, 0.89; 95% CI, 0.80-1.00; P = .05).

Child survivors of TTTS had elevated SBP and DBP measurements at 2 years of age, with no differences seen between former donor and recipient twins. Prematurity may be a risk factor for elevated BP measurements in this population. Future studies are warranted to ascertain whether these cardiovascular findings persist over time.

Coarctation of the aorta represents more than a simple obstructive lesion, as there is often evidence of hypertension and vascular dysfunction despite successful surgery at an early age. There are ample data showing that a large proportion of patients develop arterial hypertension, and this appears to increase with age. Our understanding of the pathogenesis of late hypertension is incomplete, and there is limited information on which drugs are most appropriate. Increased arterial rigidity is now well described in this patient group, although it is not known how this should influence therapy. The increase in afterload associated with this increased rigidity has been found to have an impact on the left ventricle at an early stage, and the interaction between the vascular dysfunction and the ventricle is an area of interest and active research. This article reviews some recent studies and highlights areas where research questions remain.

To determine whether patients with coarctation of the aorta (COA) were more likely to develop obesity compared with the general population or others with isolated forms of congenital heart disease.

We conducted a cross-sectional study of 160 patients who underwent COA repair at our institution between 1974 and 2009. Body mass index (BMI) measurements were obtained from the most recent clinic visit and at 5, 10, 15, and 20 years of age from retrospective chart review. BMI values were compared against established normal data to obtain age-sex matched z-scores. We also compared the rates of developing obesity over time in adults with COA vs 96 adults with other isolated forms of congenital heart disease, including aortic valve stenosis, pulmonary valve stenosis, or atrial septal defect.

After age 5 years, patients with COA had significantly greater BMI z-scores compared with age-sex matched normal data (P < .001). The proportion of obesity in patients with COA significantly increased over time (P < .001). Adults with repaired COA developed obesity at a greater rate than those with either aortic valve stenosis (P = .004) or with pulmonary valve stenosis or atrial septal defect (P < .001).

There is a greater incidence of obesity that progressively increases with age in patients with repaired COA. Adults with repaired COA developed obesity at a greater rate than those with other isolated forms of congenital heart disease. Further prospective trials are needed to confirm our observations and to elucidate the potential mechanism relating COA to obesity.

Coarctation of aorta (CoA) patients present cardiovascular complications late after repair the causes of which are not fully understood. Our study investigates the neurohormonal and immune activation and the elastic properties of the aorta and peripheral vessels in adult patients with coarctation of aorta (CoA), late after repair.

Nineteen adult patients with repaired CoA and 29 matched healthy controls underwent aortic distensibility, stiffness index, a study of the elastic properties of peripheral vessels proximal to the coarctation site and measurement of plasma cytokine and neurohormone levels.

Distensibility index was reduced (p=0.02) and stiffness index was increased (p=0.005) in CoA patients compared to control. Augmentation index (p=0.0007) and augmented pressure (p=0.001) were higher in CoA patients and Forearm Blood Flow (FBF) index was reduced (p=0.009). Plasma levels of sICAM-1 (p=0.01), sVCAM-1 (p=0.05), E-selectin (p=0.01), sFas-ligand (p=0.02) and IL-10 (p=0.01) were also elevated in CoA patients vs control. TNF-a, IL-6, Endothelin-1 and NT-pro-BNP levels were not.

Adults with repaired CoA seem to develop a late inflammatory reaction, which reflects a functional problem in all vessels, regardless of the initial lesion. This may explain the late complications of the disease despite early repair and improved surgical procedures.

Cardiovascular events are the main cause of premature death after successful repair of aortic coarctation (CoA). The aim of this study was to assess the selected biochemical markers of atherosclerosis in normotensive CoA repaired patients and to establish its relation to ultrasound indexes of vascular pathology.

62 patients after CoA repair (37 males, age: 34.1 ± 1.4 yrs) and 20 control individuals (10 males, age: 34.8 ± 2.2 yrs) were enrolled in the study. The serum markers: asymmetric dimethylarginine (ADMA), nitrites/nitrates (NOx), high-sensitivity C-reactive protein (hsCRP), and following vascular parameters: flow-mediated dilatation (FMD), intima-media thickness (IMT) and pulse wave velocity (PWV) were analyzed.

33 CoA repaired patients were normotensive, and compared to controls, they presented higher serum ADMA concentrations (0.59 ± 0.04 umol/l vs. 0.46 ± 0.03 umol/l, p=0.035). An analysis of the vascular parameters revealed decreased FMD (4.75 ± 0.5%), NMD (11.86 ± 0.8%) and increased PWV (6.90 ± 0.2 m/s) values in the normotensive patients as compared with the control group (FMD: 8.6 ± 0.9%, p<0.001, NMD: 20.94 ± 1.7%, p<0.001; PWV: 5.49 ± 0.2, p=0.023). There were no differences in the serum levels of NOx, hsCRP as well as IMT values between normotensive patients and the control group. A multivariate regression analysis revealed that serum ADMA level was a factor independently associated with the FMD value (r=-0.334; p=0.031) in normotensive CoA repaired group.

Early biochemical and vascular indices of atherosclerosis such as increased serum ADMA concentration as well as impaired vasodilatation and increased arterial stiffness are observed in patients after CoA repair. Serum ADMA is a strong predictor of endothelial dysfunction in patients with CoA repair.

Patients after successful repair of coarctation of aorta (CoAo) are at risk of hypertension at rest and associated end-organ damage. The aim of the study was to assess arterial stiffness and function in adults after coarctation repair in relation to descending aorta (AoD) residual coarctation and patient's age at operation.

85 patients after CoAo repair (53 males) aged 34.6 ± 10.3 years; median age at operation 0.9 ± 8.2 years. The control group-30 individuals (18 males) at mean age 33.6 ± 8.2 years. The following central parameters: augmentation pressure (AP) and augmentation index (AI) as well as peripheral vascular parameters: flow-mediated dilatation (FMD), nitroglycerin-mediated vasodilatation (NMD), intima-media thickness (IMT) and pulse wave velocity (PWV) were measured.

47 CoAo-repaired patients were normotensive, and compared to control, they presented higher values of central parameters AP (7.3 ± 4.6 vs. 4.4 ± 3.6 mmHg; p = 0.002) and AI (18.6 ± 10.4 vs. 13.5 ± 4.3%; p = 0.03); as well as the increased PWV (6.8 ± 1.2 vs. 5.4 ± 0.9 m/s; p = 0.003), while IMT was comparable (0.53 ± 0.01 vs. 0.51 ± 0.01 mm; p = 0.06). The vasodilatation was impaired in the normotensive patients: FMD (4.8 ± 2.8 vs. 8.5 ± 2.3%; p = 0.00003) and NMD (11.3 ± 4.6 vs. 19.8 ± 7.2%; p = 0.00001). The comparison of recoarctation (46, 54%) to non-recoarctation (39, 46%) patients did not reveal any significant differences in resting systolic and diastolic pressures, as well as the values of AI and the peripheral vascular parameters; the value of AP was higher in the recoarctation patients (10.5 ± 6.9 vs. 7.5 ± 4.1; p = 0.02) and correlated positively with the gradient across AoD (r = 0.295, p = 0.01). There was no significant linear correlation between age at the time of surgery and any of peripheral arterial parameters.

Residual stenosis in AoD does not affect the arterial vasodilatation nor stiffness in patients after CoAo repair. Early operation has no impact on peripheral vascular remodeling or central pressure which supports the claim that coarctation of the aorta is a systemic vascular disorder which leads to progressive vascular and end-organ damage despite early correction.

Patients with coarctation of the aorta develop early onset hypertension in spite of early effective repair. This is associated with significant morbidity and is arguably the single most important outcome variable in this patient group. We discuss the potential pathophysiological mechanisms involved in the development of hypertension with clinical reference to monozygotic twins, and review potential strategies for therapy and prevention in this setting.

Regardless of a successful operation, patients with coarctation of aorta (CoAo) are exposed to the risk of hypertension and a propensity to vascular and end-organ damage. The aim of this study is to evaluate the influence of residual aorta stenosis as well as the age at the operation on the parameters of arterial function and structure in patients after CoAo repair. Eighty-five patients after CoAo repair (53 males; mean age: 34.6 ± 10.3 years, mean age at the repair: 10.9 ± 8.2 years) were enrolled in the study. The control group consisted of 30 healthy subjects (18 males; mean age: 33.6 ± 8.2 years). Indices of systemic arterial remodeling [flow-mediated dilatation (FMD), nitroglycerine-mediated vasodilatation (NMD), carotid intima-media thickness (IMT), pulse wave velocity (PWV)] were analyzed in all study patients. In normotensive patients after CoAo repair (47/55%), a significantly increased PWV was observed in comparison to the control group (6.8 ± 1.2 vs. 5.4 ± 0.9 m/s; p = 0.003), with no difference in IMT values (0.53 ± 0.1 vs. 0.51 ± 0.1 mm; p = 0.06). Mean FMD (4.8 ± 2.8 vs. 8.5 ± 2.3%; p = 0.00003) and NMD (11.3 ± 4.6 vs. 19.8 ± 7.2%; p = 0.00001) were lower than in the controls. In patients with a residual aorta stenosis (46/54%), defined as an arm-leg pressure gradient ≥ 20 mmHg, no differences were found within the scope of both systolic and diastolic blood pressure and of all of the examined vascular parameters. No significant correlations were revealed between the vascular parameters and the gradient across descending aorta as well as the age at the operation. Residual stenosis in the descending aorta does not affect the arterial vasodilatation nor stiffness in patients after CoAo repair. An early surgery does not influence the remodeling of the vessels, which supports the thesis that CoAo is a generalized vascular disease and that even an early operation cannot prevent the progressive and vascular changes and end-organ damage.

Objectives. Stenting for native and recurrent coarctation (COA) in adults has become an important therapeutic strategy. In this prospective observational study we evaluated the intermediate-term outcome of stent implantation for either native or recurrent (re)COA in adults.Methods. All adults who underwent stent implantation in our institution between January 2003 and December 2008 were included. Diagnosis of (re)COA was based upon a combination of clinical signs, noninvasive imaging or invasive gradient measurements. NuMED stents were implanted under general anaesthesia.Results. Twenty-four patients (50% male) underwent stent implantation for native (n=6) or reCOA (n=18) at a median age of 36 (18 to 60) years. There was significant improvement in pre- versus post-stent invasive systolic gradient (19 vs. 0 mmHg, p<0.001) and COA diameter (10 vs. 16 mm, p<0.001). Acute complications (12.5%) included death due to aortic rupture despite immediate successful coverage with a covered stent (n=1) and groin haematoma (n=2). During a median follow-up period of 33 (8 to 77) months (n=22), late complications occurred in three patients (13.6%): stent migration to the ascending aorta (n=1), pseudoaneurysm at the site of the initial stent (n=1), and occluded external iliac artery (n=1). Stent implantation did not reduce the need for antihypertensive medication or blood pressure at last follow-up. Conclusion. COA stenting results in a significant gradient decrease and increase in vessel diameter. However, serious complications do occur and hypertension remains in the majority of patients. (Neth Heart J 2010;18:430-6.).

Even after successful repair, hypertension is one of the main determinants of cardiovascular morbidity and mortality in patients with aortic coarctation (CoA). We compared the effect of candesartan (angiotensin II receptor blockade) and metoprolol (beta-adrenergic receptor blockade) on blood pressure, large artery stiffness, and neurohormonal status in hypertensive patients after repair of CoA. In the present open-label, crossover study, hypertensive patients after CoA repair were first randomly assigned to treatment with candesartan 8 mg or metoprolol 100 mg once per day. After 8 weeks of treatment with one of the drugs, the other treatment was given for 8 weeks. The treatment effects were assessed with 24-hour ambulatory blood pressure monitoring, measurement of large artery stiffness, and neurohormonal plasma levels at baseline and after 8 weeks of either treatment. Sixteen patients (mean age 37 +/- 12 years, 26 +/- 15 years after repair, 63% men) completed the study. The 24-hour mean arterial pressure at baseline was 97.7 +/- 6.2 mm Hg. Metoprolol (mean dose 163 +/- 50 mg/day) decreased the mean arterial pressure (7.0 +/- 4.2 and 4.1 +/- 3.6 mm Hg, respectively) more than did candesartan (mean dose 13 +/- 4 mg/day; p = 0.018, 95% confidence interval 0.6 to 5.5). Large artery stiffness did not change with either treatment. With metoprolol, plasma B-type natriuretic peptide increased and plasma renin decreased. With candesartan, the plasma renin and noradrenaline levels increased and aldosterone levels decreased. In conclusion, in adult hypertensive patients after CoA repair, metoprolol had more of an antihypertensive effect than did candesartan. Moreover, the neurohormonal outcome did not support a significant role for the renin-angiotensin system in the causative mechanism of hypertension after CoA.

The purpose of this study was to evaluate the effect of ramipril on endothelial function and inflammatory process in a group of normotensive subjects with successfully repaired coarctation of the aorta (SCR).

Subjects with SCR experience higher long-term cardiovascular risk as a result of the relapse of arterial hypertension or owing to nonreversible structural changes in the pre-coarctation arterial tree. These subjects experience endothelial dysfunction in the right forearm and appear to have elevated levels of proatherogenic inflammatory markers, even in the absence of arterial hypertension.

Twenty young individuals age 27.3 +/- 2.4 years old with SCR 13.9 +/- 2.2 years previously, received ramipril 5 mg/day for 4 weeks in a randomized, cross-over, controlled trial. Endothelial function was evaluated in the right forearm by gauge-strain plethysmography, and serum levels of interleukin (IL)-1b, IL-6, soluble CD40 ligand (sCD40L), and soluble vascular cell adhesion molecule (sVCAM)-1 were determined by enzyme-linked immunosorbent assay.

Ramipril improved endothelial function (p < 0.001) and decreased the expression of proinflammatory cytokine IL-6 (p < 0.05) and sCD40L (p < 0.01). Furthermore, ramipril decreased serum levels of sVCAM-1 (p < 0.01) but failed to affect serum levels of C-reactive protein. These effects were independent of blood pressure lowering.

Ramipril reversed the impaired endothelial function and decreased the expression of proinflammatory cytokine IL-6, sCD40L, and adhesion molecules in normotensive subjects with SCR. These findings imply that ramipril treatment may have antiatherogenic effects in subjects with SCR, even in the absence of arterial hypertension.

Hypertension occurs in 20% to 40% of survivors of anatomically successful repair of aortic coarctation (CoA). The aim of the present study was to examine the role of central aortic function in this setting.

Forty normotensive asymptomatic subjects with successful CoA repair (age 12 +/- 8 years) and 20 age- and sex-matched control subjects underwent detailed magnetic resonance imaging investigation of the thoracic aorta and left ventricle. Aortic distensibility, compliance, and stiffness beta index were calculated in the central (precoarctation) and descending (postcoarctation) aorta. Aortic pulse wave velocity was measured and left ventricular mass was calculated.

Compared to control subjects, CoA subjects had markedly decreased central aortic distensibility (2.8 +/- 0.7 vs 4.2 +/- 0.5 mm Hg(-1) x 10(-3), P < .001) and compliance (1.7 +/- 0.3 vs 2.5 +/- 0.6 mm2 mm Hg(-1), P < .001) and increased stiffness beta index (5.2 +/- 1 vs 2.5 +/- 0.6, P < .001). Pulse wave velocity was also significantly increased in the CoA subjects (4.7 +/- 1.3 vs 3.3 +/- 0.6 m/sec, P < .001). Left ventricular mass index was higher in the CoA subjects (84 +/-11 vs 73 +/-10 g/m2, P = .01) and correlated significantly with aortic stiffness beta index (r2 = 0.8, P < .0001). By contrast, descending aortic characteristics were similar in the CoA and control subjects.

Central aortic stiffness is markedly increased and associated with increased left ventricular mass in normotensive young subjects after successful early repair of CoA.

The long-term follow-up data subsequent to a successful repair of AoC (aortic coarctation) show that life expectancy remains reduced. Previous standard echocardiographic studies have demonstrated normal or increased systolic cardiac function in patients following successful repair of AoC. SR (strain rate) imaging is a new technique able to detect subclinical myocardial abnormalities. In the present study we investigated whether young patients (without hypertension, as assessed using ambulatory blood pressure monitoring and an exercise test) following successful AoC repair already have abnormal myocardial deformation properties, and the relationship of the deformation properties with aortic stiffness. We studied 166 subjects, 83 AoC non-hypertensive patients (mean age 12+/-4 years) a number of years after successful repair of AoC and 83 age- and sex-matched subjects as controls. Peak systolic SR (1/s) for both regional longitudinal and radial function was assessed. The aortic stiffness index was calculated from the echocardiographically derived thoracic aortic diameters, and the measurement of blood pressure was obtained by cuff sphygmomanometry. The LV (left ventricular) ejection fraction was significantly increased in AoC patients, whereas regional longitudinal SRs were significantly reduced (-1.1+/-0.9 compared with -2+/-0.5, P<0.0001) in patients. The aortic stiffness index was significantly increased in AoC patients (12+/-9, P<0.0001). At multilinear regression analysis, age at repair (P=0.005; coefficient, -0.201; S.E.M., 0.027) and the aortic stiffness index (P=0.0029; coefficient, 0.334; S.E.M., 0.423) predicted longitudinal SR. Despite the presence of a successful repair for AoC, in the absence of hypertension, longitudinal deformation properties were significantly impaired. Moreover, the degree of longitudinal SR impairment was correlated with age at repair and aortic stiffness. Early repair can delay the onset of hypertension in postcoarctectomy patients, but cannot prevent the innate structural and functional abnormalities of the aorta and their deleterious effect on myocardial deformation properties.

Although for most children the process of atherosclerosis is subclinical, dramatically accelerated atherosclerosis occurs in some pediatric disease states, with clinical coronary events occurring in childhood and very early adult life. As with most scientific statements about children and the future risk for cardiovascular disease, there are no randomized trials documenting the effects of risk reduction on hard clinical outcomes. A growing body of literature, however, identifies the importance of premature cardiovascular disease in the course of certain pediatric diagnoses and addresses the response to risk factor reduction. For this scientific statement, a panel of experts reviewed what is known about very premature cardiovascular disease in 8 high-risk pediatric diagnoses and, from the science base, developed practical recommendations for management of cardiovascular risk.

We sought to assess the impact of persistent hypoplasia of the transverse aortic arch (TAA) after repair of aortic coarctation (AoC), on blood pressure response to exercise, left ventricular (LV) hypertrophy and presence of collateral circulation.

34 consecutive patients with end-to-end repair of AoC (age at repair 3.2+/-2.5 years) underwent exercise echocardiography and magnetic resonance imaging (MRI) at 24+/-7 years of age (range 11.3 to 44.6 years). Systolic Doppler pressure gradient (SPG) across the descending aorta and blood pressure at the right arm were measured at baseline and every minute throughout all exercise. Magnetic resonance imaging was used to measure LV mass index, presence and amount of collateral flow, and the diameters of the aortic isthmus and TAA indexed to the diameter of the diaphragmatic.

Aortic isthmus index was higher than that of the TAA (p=0.006). We observed LV hypertrophy in 15 patients (45%) and presence of collateral circulation in 14 (41%). Eighteen patients (53%) had an abnormal blood pressure response to exercise. Patients with abnormal pressure response to exercise had smaller TAA index (p=0.0005), but similar aortic isthmus index (p=0.09). They also had higher exercise SPG (p<0.0001), higher LV mass index (p<0.0001) and prevalence of LV hypertrophy (p=0.007), higher prevalence of collateral circulation (p<0.0001) and a higher amount of collateral flow (p<0.0001). TAA index, but not aortic isthmus index, correlated with exercise blood pressure (r=-0.59, p=0.003), exercise SPG (r=-0.70, p=0.0005), amount of collateral flow (r=-0.74, p=0.0002) and LV mass index (r=-0.68, p=0.0007).

After repair of AoC, hypoplasia of the TAA may be responsible for abnormal blood pressure response to exercise, persistence of collateral circulation and LV hypertrophy.

In severe aortic coarctation in the neonatal period, surgical repair is required soon after clinical stabilization. Elective repair of isolated aortic coarctation is nowadays indicated at 3-6 months of life or at the time of diagnosis. At present, no single operation appears to have a clear superiority. However, during the first months of life, an extended end-to-end anastomosis is considered the best option by most authors, even though weight at operation and anatomy of the aortic arch are also significant determinants of late recoarctation. In cases of aortic arch hypoplasia, which occurs in up to 70% of neonatal and infant coarctations, especially when associated anomalies are present, surgery seems the treatment of choice. After 3 months of age and in the adult population, balloon angioplasty and stent placement are considered a suitable option. Recently, we adopted a median sternotomy approach without the use of extracorporeal circulation for the treatment of aortic coarctation with a hypoplastic aortic arch. We treated 11 patients with satisfactory results at an average follow-up of 40 months.

Ageing is associated with increased leg vascular resistance and reductions in leg blood flow during rest and exercise, potentially predisposing older adults to a host of functional and cardiovascular complications. The purpose of these studies was to examine the effects and possible mechanisms of ageing and exercise training on arteriolar adrenergic vasoreactivity. Young and old male Fischer 344 rats were divided into young sedentary (YS), old sedentary (OS), young exercise-trained (YT) or old exercise-trained (OT) groups, where training consisted of chronic treadmill exercise. Isolated soleus (SOL) and gastrocnemius (GAS) muscle arterioles were studied in vitro. Responses to noradrenaline in endothelium-intact and endothelium-denuded arterioles, as well as during nitric oxide synthase (NOS) inhibition were determined. Vasodilator responses to isoproterenol and forskolin were also determined.

Noradrenaline-mediated vasoconstriction was increased in SOL arterioles with ageing, and exercise training in old rats attenuated alpha-adrenergic vasoconstriction in arterioles from both muscle types. Removal of the endothelium and NOS inhibition eliminated these ageing and training effects. Isoproterenol-mediated vasodilatation was impaired with ageing in SOL and GAS arterioles, and exercise training had little effect on this response. Forskolin-induced vasodilatation was not affected by age. The data demonstrate that ageing augments alpha-adrenergic vasoconstriction while exercise training attenuates this response, and both of these alterations are mediated through an endothelial alpha-receptor-NOS-signalling pathway. In contrast, ageing diminishes beta-receptor-mediated vasodilatation, but this impairment is specific to the smooth muscle. These studies indicate that alpha- and beta-adrenergic mechanisms may serve to increase systemic vascular resistance with ageing, and that the effects of exercise training on adrenergic vasomotor properties could contribute to the beneficial effects of exercise on cardiovascular disease.

In patients, after repair of aortic coarctation, abnormal function of the proximal precoarctation arterial conduits has been demonstrated, but data on arterial wall structure of proximal and distal arteries in patients are scarce. The aim of our study is to compare intima-media thickness (IMT) of the carotid and femoral arteries in controls and patients after coarctation repair and to identify independent predictors of carotid and femoral IMT.

A total of 137 patients after repair of aortic coarctation (89 male, median age 29.7 years, range 17-74 years, and median age at repair 6.3 years, range 0.01-46 years) and 46 age-matched controls underwent ambulatory blood pressure monitoring and B-mode ultrasound of the carotid and femoral arteries.

Twenty (15%) of the 137 patients were operated on before the age of 1 year ("early repair"). The patients with an early repair were younger compared to the controls and compared with the patients with a late repair (24.5 [10.5] vs 31.6 [8.4] years, P = .005, and vs 32.1 [10.5] years, P < .001, respectively). Eighty patients (59%) had hypertension on the basis of the results of the ambulatory blood pressure monitoring (mean daytime blood pressure > or = 135/85 mm Hg). The prevalence of hypertension was not significantly different between patients with an early or late repair. Although patients with an early repair were younger, both carotid and femoral IMT were increased in these patients compared to controls (common carotid artery 0.57 [0.11] vs 0.49 [0.07] mm, P < .001; common femoral artery 0.48 [0.10] vs 0.44 [0.05] mm, P = .033). In multivariable regression analyses, age at repair was only an independent predictor of femoral and not of carotid IMT.

Patients, after repair of aortic coarctation, have increased carotid and femoral IMT despite normal ambulatory blood pressures and successful previous repair. Early repair seems to preserve postcoarctation arterial wall structure, but seems to have only limited effect on precoarctation vessel walls, which supports the theory of a developmental defect of the proximal aorta and its branches.

Despite successful surgical repair, aortic coarctation is associated with unfavourable prognosis mainly due to cardiovascular disease. Late timing of repair and arterial hypertension represent adverse prognostic factors. Arterial hypertension can recur after coarctation repair, despite the absence of residual obstruction, with a prevalence of up to 45%. Furthermore, even subjects with normal blood pressure values at rest may show an abnormal blood pressure elevation during exercise and daily life activities. The pathophysiology of such abnormal blood pressure behaviour is unclear. Different mechanisms have been proposed: resetting of the renin-angiotensin system, neurological dysfunction and impaired vascular reactivity and/or elastic properties. Several studies have supported these hypotheses, although the suggestion of a causative role of vascular dysfunction persisting late after coarctation repair has recently become more popular. Further studies are needed to investigate this issue; this particular syndrome may represent an important study model for the understanding of systolic hypertension.

It is well documented that in patients with coarctation of the aorta life expectancy is not normal even after successful coarctation repair (SCR), primarily due to cardiovascular events. We examined endothelial function in the forearm circulation, the mechanical properties and intima/media thickness in carotid and femoral arteries and the inflammatory process in normotensive patients, after coarctation repair. Fifteen patients, 29+/-2 years old, 12+/-2.9 years after SCR and 16 age- and sex-matched controls were enrolled in our study. Forearm blood flow was determined by gauge-strain plethysmography. Forearm vasodilatory response to reactive hyperemia was expressed as the %change from baseline to post-reactive hyperemia blood flow. High resolution ultrasound was used for determination of intima/media thickness and elastic properties of carotid and femoral arteries. Serum levels of soluble vascular adhesion molecule 1 (sVCAM-1), intercellular adhesion molecule 1 (sICAM-1), E-selectin, and interleukines 1b (IL-1b) and 6 (IL-6) were determined by ELISA. Reactive hyperemia was significantly decreased in patients compared to controls (p<0.01). Patients with SCR had higher intima/media thickness and decreased distensibility in the carotid arteries than controls (p<0.01 for both). Serum levels of sICAM-1, sSVCAM-1, E-selectin and IL-1b were higher in SCR group than in controls (p<0.05 for all). Adult patients after SCR have impaired endothelial function in the forearm circulation, increased intima/media thickness, decreased distensibility in the carotid arteries and increased levels of proinflammatory cytokines and adhesion molecules than healthy controls. These results may partly explain the high incidence of coronary artery disease in patients with repaired coarctation of the aorta.

Survival of patients with aortic coarctation has dramatically improved after surgical repair became available and the number of patients who were operated and reach adulthood is steadily increasing. However, life expectancy is still not as normal as in unaffected peers. Cardiovascular complications are frequent and require indefinite follow-up. Concern falls chiefly in seven categories: recoarctation, aortic aneurysm formation or aortic dissection, coexisting bicuspid aortic valve, endocarditis, premature coronary atherosclerosis, cerebrovascular accidents and systemic hypertension. In this review, these complications, with particular reference to late hypertension, are discussed and strategies for the clinical management of post-coarctectomy patients are described.

To identify factors predisposing to abnormal left ventricular geometry and mechanics in 52 patients after successful repair of aortic coarctation.

We evaluated left ventricular remodelling, systolic midwall mechanics, and isthmic gradient by echo-Doppler, systemic blood pressure at rest/exercise and by ambulatory blood pressure monitoring, and the aortic arch by magnetic resonance imaging. Echocardiographic findings were compared with those of 142 controls. The patients with aortic coarctation showed an increased indexed left ventricular end-diastolic volume, increased mass index, increased ratio of mass to volume and systolic chamber function. The contractility, estimated at midwall level, was increased in 21 percent of the patients. In 26 (50 percent) of the patients, we found abnormal left ventricular geometry, with 9 percent showing concentric remodelling, 33 percent eccentric hypertrophy, and 8 percent concentric hypertrophy. These patients were found to be older, underwent a later surgical repair, and to have higher systolic blood pressures at rest and exercise as well as during ambulatory monitoring. The relative mural thickness and mass index of the left ventricle showed a significant correlation with different variables on uni- and multivariate analysis. Age and diastolic blood pressure at rest are the only factors associated with abnormal left ventricular remodelling.

Patients who have undergone a seemingly successful surgical repair of aortic coarctation may have persistently abnormal geometry with a hyperdynamic state of the left ventricle. This is more frequent in older patients, and in those with higher diastolic blood pressures.

The significance of mild residual descending aortic narrowing in post-coarctectomy patients is not known. The aim of our study was to investigate the influence of mild residual descending aortic narrowing on blood pressure and vascular damage in patients after repair of aortic coarctation.

In 107 consecutive post-coarctectomy patients, magnetic resonance imaging, ambulatory blood pressure monitoring, and B-mode ultrasound of the carotid arteries were performed. A significant residual aortic narrowing was defined as: (i) a resting blood pressure gradient > or =30 mmHg with hypertension or exercise-induced hypertension (European Society of Cardiology guidelines); and/or (ii) a site of repair/diaphragmatic aorta ratio <0.7. Thirty-four patients (32%) had a significant residual aortic narrowing and were excluded from the analysis. Of the remaining 73 patients (43 male) with no or only mild residual descending aortic narrowing, median age was 29.8 years (range 17.1-52.5 years), mean age at repair 8.1 years (range 0.02-37.3 years), mean arm/leg gradient 2+/-12 mmHg, and mean common carotid intima-media thickness 0.612+/-0.118 mm. Thirty-three (45%) of these patients had hypertension. In multivariable regression analysis the site of repair/diaphragmatic aorta ratio was a strong and independent predictor of mean daytime systolic blood pressure (P<0.001) and common carotid intima-media thickness (P=0.027).

Mild residual descending aortic narrowing in post-coarctectomy patients is independently associated with mean daytime blood pressure and carotid intima-media thickness. Our data suggest that a threshold for re-intervention of residual aortic narrowing lower than posed in current guidelines may be desirable to improve long-term outcome in these patients. However, further research on such aggressive interventional approaches is needed.

To investigate whether exercise-induced hypertension in successfully repaired adult post-coarctectomy patients is associated with hypertension on 24-h blood pressure measurement and increased left ventricular mass.

One hundred and forty-four consecutive post-coarctectomy patients (mean age 31.5 years, range 17-74 years; mean age at repair 7.9 years, range 0-45 years) from three tertiary referral centres were studied using ambulatory blood pressure monitoring, treadmill exercise testing and echocardiography.

Of the 144 patients, 27 (19%) were known to have sustained hypertension, based on their history, and all were on antihypertensive medication. However, 32 (27%) of the remaining 117 patients showed elevated mean daytime systolic blood pressure readings at 24-h ambulatory blood pressure monitoring (systolic blood pressure > or = 140 mmHg). Of the remaining 85 patients with normal mean daytime systolic blood pressure, 18 patients (21%) had exercise-induced hypertension (maximal exercise systolic blood pressure > 200 mmHg). Mean daytime systolic blood pressure was higher in the exercise-induced hypertensive patients compared to the normotensive patients with normal exercise blood pressure (134 +/- 5 versus 129 +/- 7 mmHg, P = 0.008). By multivariate analysis, both maximal exercise systolic blood pressure (P = 0.007) and resting systolic blood pressure (P < 0.0001) were independently associated with mean daytime systolic blood pressure. Maximal exercise systolic blood pressure had no independent predictive value for left ventricular mass (P = 0.132).

In adult post-coarctectomy patients, maximal exercise systolic blood pressure is independently associated with mean daytime systolic blood pressure at ambulatory blood pressure monitoring. In this study no independent predictive value of maximal exercise systolic blood pressure for left ventricular mass could be demonstrated.

To determine the relationship between percent stenosis and three indicators of hemodynamic significance-arm-leg blood pressure gradient, direct visualization of collaterals, and percent increase flow from proximal to distal descending thoracic aorta-in patients with prior repair of coarctation of the aorta (CoA).

Magnetic resonance imaging (MRI) examinations of 19 patients with prior repair of CoA were retrospectively reviewed. Percent stenosis was compared to the arm-leg blood pressure gradient as obtained from chart review, the depiction of collaterals by gadolinium-enhanced magnetic resonance angiography (MRA), and the percent increased flow in the distal thoracic aorta as measured by velocity-encoded cine MRI. Some imaging series or blood-pressure values were not available in some patients. All of the data were available for 15 of the 19 patients.

The arm-leg blood pressure gradient showed no statistical association with percent stenosis (R(2) = 0.10, P = 0.22), direct visualization of collaterals (P = 0.80), or percent increase in flow (R(2) < 0.01, P = 0.85). Percent stenosis did show association with visualization of collaterals (P = 0.01) and increase flow (R(2) = 0.62, P < 0.01).

The arm-leg blood pressure gradient is not a reliable indicator of hemodynamic significance of restenosis in patients with prior repair of CoA. Direct visualization of collateral vessels by MRA and percent increase in flow from proximal to distal descending thoracic aorta are reliable indicators of hemodynamic significance.

While often considered to be cured, patients with repaired coarctation of the aorta frequently have premature morbidity and even mortality.

Unlike quadrupeds, the legs of humans are regularly exposed to elevated pressures relative to the arms. We hypothesized that this "dependent hypertension" would be associated with altered adrenergic responsiveness. Isoproterenol (0.75-24 ng x 100 ml limb volume-1 x min-1) and phenylephrine (0.025-0.8 microg x 100 ml limb volume-1 x min-1) were infused incrementally in the brachial and femoral arteries of 12 normal volunteers; changes in limb blood flow were quantified by using strain-gauge plethysmography. Compared with the forearm, baseline calf vascular resistance was greater (38.8 +/- 2.5 vs. 26.9 +/- 2.0 mmHg x 100 ml x min x ml-1; P < 0.001) and maximal conductance was lower (46.1 +/- 11.9 vs. 59.4 +/- 13.4 ml x ml-1 x min-1 x mmHg-1; P < 0.03). Vascular conductance did not differ between the two limbs during isoproterenol infusions, whereas decreases in vascular conductance were greater in the calf than the forearm during phenylephrine infusions (P < 0.001). With responses normalized to maximal conductance, the half-maximal response for phenylephrine was significantly less for the calf than the forearm (P < 0.001), whereas the half-maximal response for isoproterenol did not differ between limbs. We conclude that alpha1- but not beta-adrenergic-receptor responsiveness in human limbs is nonuniform. The relatively greater response to alpha1-adrenergic-receptor stimulation in the calf may represent an adaptive mechanism that limits blood pooling and capillary filtration in the legs during standing.

Late cardiovascular complications after operative repair of coarctation of the aorta include systemic hypertension, premature coronary artery disease, aortic valve abnormalities, aortic aneurysm, and recoarctation. We report the outcome in 274 subjects greater-than-or-equal50 years after coarctation repair. Operative repair of simple coarctation was performed on 274 patients at the University of Minnesota Hospital between 1948 and 1976. Twenty patients (7%) died in the immediate postoperative period. Of the 254 survivors, 2 were lost to follow-up, 45 (18%) died at a mean age of 34 years, and 207 (81%) were alive greater-than-or-equal50 years after the original operation. Coronary artery disease and perioperative deaths at the time of a second cardiac operation accounted for 17 of the 45 late deaths. Predictors of survival were age at operation and blood pressure at the first postoperative visit. Of the 207 long-term survivors, 92 (48%) participated in a clinical cardiovascular evaluation. Thirty-two of the 92 subjects had systemic hypertension that was predicted by age at operation, blood pressure at the first postoperative visit, and paradoxic hypertension at operative repair. New cardiovascular abnormalities detected at follow-up evaluation included evidence of a previous myocardial infarction, cardiomyopathy, atrial fibrillation, moderate to severe left ventricular outflow tract obstruction, moderate aortic valve regurgitation, recoarctation, and ascending aortic dilation. Thus, long-term survival is significantly affected by age at operation, with the lowest mortality rates observed in patients who underwent surgery between 1 and 5 years of age. More than 1/3 of the survivors developed significant late cardiovascular abnormalities.

Although data exist that address the attempt to correlate noninvasive Doppler-derived pressure gradients with invasive catheter pressure gradients in patients with coarctation of the aorta, few data exist about stiffness of the proximal descending aorta (precoarctation) and its relation to these pressure measurements. In this study, an in vitro flow model of a simulated neonatal aorta with a coarctation was developed. Three proximal descending aortas of different stiffnesses were used. The stiffness index of the proximal descending aorta was calculated as beta = ln [systolic pressure/diastolic pressure/(systolic diameter - diastolic diameter)]. We evaluated pressure gradients obtained by continuous wave Doppler and standard catheter methods and looked at acceleration of flow velocity determined by pulsed wave Doppler in the 3 precoarctation segments of differing stiffnesses. Pressures in the proximal descending aorta (precoarctation) increased with increasing stiffness, ranging from 105 mm Hg (soft) to greater than 300 mm Hg (stiff). Continuous wave Doppler instantaneous pressure gradients overestimated the catheter instantaneous pressure gradients substantially (mean 41% +/- 19%). The stiffer the precoarctation segment, the more the degree of overestimation: soft, 0% to 63% (= 3.47); medium, 13% to 54% (beta = 4.42); and stiff, 43% to 66% (beta = 5.91). Inclusion of the precoarctation velocity [V1] component in the Bernoulli equation did not significantly improve the correlation or the agreement. An additional observation was that pullback catheter peak-to-peak gradients were higher than simultaneous peak-to-peak gradients. In the stiff aorta, this difference could be greater than 22 mm Hg (>19%). Acceleration of flow velocity toward the coarctation was evident by pulsed wave Doppler interrogation. Increasing the stiffness of the precoarctation segment also increased the degree of acceleration within this proximal segment: soft, 0.4 to 0.8 m/s; medium, 0.5 to 1. 4 m/s; and stiff, 0.7 to 1.5 m/s. These data suggest that increasing stiffness of the proximal descending aorta can alter the continuous wave detected Doppler gradient and although the gradient itself has increased, it may not predict accurately the true severity of the localized, most severely obstructed segment.