Angiographic tool to detect pulmonary arteriovenous malformations in single ventricle physiology.

OBJECTIVE: Individuals with single ventricle physiology who are palliated with superior cavopulmonary anastomosis (Glenn surgery) may develop pulmonary arteriovenous malformations. The traditional tools for pulmonary arteriovenous malformation diagnosis are often of limited diagnostic utility in this patient population. We sought to measure the pulmonary capillary transit time to determine its value as a tool to identify pulmonary arteriovenous malformations in patients with single ventricle physiology. METHODS: We defined the angiographic pulmonary capillary transit time as the number of cardiac cycles required for transit of contrast from the distal pulmonary arteries to the pulmonary veins. Patients were retrospectively recruited from a single quaternary North American paediatric centre, and angiographic and clinical data were reviewed. Pulmonary capillary transit time was calculated in 20 control patients and compared to 20 single ventricle patients at the pre-Glenn, Glenn, and Fontan surgical stages (which were compared with a linear-mixed model). Correlation (Pearson) between pulmonary capillary transit time and haemodynamic and injection parameters was assessed using angiograms from 84 Glenn patients. Five independent observers calculated pulmonary capillary transit time to measure reproducibility (intraclass correlation coefficient). RESULTS: Mean pulmonary capillary transit time was 3.3 cardiac cycles in the control population, and 3.5, 2.4, and 3.5 in the pre-Glenn, Glenn, and Fontan stages, respectively. Pulmonary capillary transit time in the Glenn population did not correlate with injection conditions. Intraclass correlation coefficient was 0.87. CONCLUSIONS: Pulmonary angiography can be used to calculate the pulmonary capillary transit time, which is reproducible between observers. Pulmonary capillary transit time accelerates in the Glenn stage, correlating with absence of direct hepatopulmonary venous flow.

Diagnosis and Management of Congenital Coronary Artery Fistulas in Infants and Children.

PURPOSE OF REVIEW: Coronary artery fistulas (CAFs) are rare coronary anomalies that most often occur as congenital malformations in children. Although most children with CAFs are asymptomatic at the time of diagnosis, some present with symptoms of congestive heart failure in the setting of large left-to-right shunts. Others may develop additional complications including coronary artery ectasia and coronary thrombosis. Surgical and transcatheter closure techniques have been previously described. This review presents the classifications of CAFs in children and the short and long-term outcomes of CAF closure in children in the reported literature. We also summarize previously-reported angiographic findings and post-treatment remodeling characteristics in pediatric patients. RECENT FINDINGS: With advancements in cross-sectional imaging technologies, anatomic delineation of CAFs via these modalities has become crucial in procedural planning. Recent reports of surgical and transcatheter closure of CAFs in children have reported good procedural success and low rates of short-term morbidity and mortality. Distal-type CAFs have elevated risk for long-term sequelae post-closure compared to proximal-type CAFs. A recent report of a multi-institutional cohort also describes post-closure remodeling classifications which may predict long-term outcomes in these patients as well as guide individualized anticoagulation management. Invasive closure of significant CAFs via surgical or transcatheter techniques is feasible and safe in most children with good short and intermediate-term outcomes. However, close clinical and imaging follow-up is required to monitor for late complications even after successful closure. Antiplatelet and anticoagulation regimens remain important aspects of post-closure management, but the necessary intensity and duration of such therapy remains unknown.

Comparison of the investigational device exemption and post-approval trials of the Melody transcatheter pulmonary valve.

OBJECTIVE: We compared 5-year outcomes of transcatheter pulmonary valve (TPV) replacement with the Melody TPV in the post-approval study (PAS) and the investigational device exemption (IDE) trial. BACKGROUND: As a condition of approval of the Melody TPV after the IDE trial, the Food and Drug Administration required that a PAS be conducted to evaluate outcomes of TPV replacement in a "real-world" environment. The 5-year outcomes of the PAS have not been published, and the IDE and PAS trials have not been compared. METHODS: The cohorts comprised all patients catheterized and implanted at 5 IDE sites and 10 PAS sites. Differences in trial protocols were detailed. Time-related outcomes and valve-related adverse events were compared between the two trials with Kaplan-Meier curves and log-rank testing. RESULTS: 167 patients (median age, 19 years) were catheterized and 150 underwent TPV replacement in the IDE trial; 121 were catheterized (median age, 17 years) and 100 implanted in the PAS. Freedom from hemodynamic dysfunction (p = .61) or any reintervention (p = .74) over time did not differ between trials. Freedom from stent fracture (p = .003) and transcatheter reintervention (p = .010) were longer in PAS, whereas freedom from explant (p = .020) and TPV endocarditis (p = .007) were shorter. Clinically important adverse events (AEs) were reported in 14% of PAS and 7.2% of IDE patients (p = .056); the incidence of any particular event was low in both. CONCLUSIONS: Hemodynamic and time-related outcomes in the PAS and IDE trials were generally similar, confirming the effectiveness of the Melody TPV with real-world providers. There were few significant complications and limited power to identify important differences in AEs. The lack of major differences in outcomes between the two studies questions the usefulness of mandated costly post-approval studies as part of the regulatory process for Class III medical devices.

Pre-procedural CT imaging aids neonatal PDA stenting for ductal-dependent pulmonary blood flow with reduction in overall procedural morbidity.

Patent ductus arteriosus stenting for ductal-dependent pulmonary blood flow is a technically challenging neonatal procedure to maintain a stable pulmonary circulation. Pre-procedural computed tomography imaging aids in outlining ductal origin, insertion, size, course and curvature. Computed tomography imaging may add value to procedural outcomes and reduce overall procedural morbidity in neonatal patent ductus arteriosus stenting. We conducted a single centre retrospective chart review of neonates with ductal-dependent pulmonary blood flow who underwent patent ductus arteriosus stenting between January 1, 2014 and June 31, 2020. We compared patients variables between patients who underwent pre-procedural computed tomography imaging to those who did not. A total of 64 patients were referred for patent ductus arteriosus stenting with 33 (52%) obtaining pre-procedural computed tomography imaging. Average age [19 days; range 1-242 days (p = 0.85)] and weight [3.3 kg (range 2.2-6.0 kg; p = 0.19)] was not significantly different between the groups. A diagnosis of pulmonary atresia was made in 42 out of 64 (66%) patients prior to patent ductus arteriosus stenting. The cohort with pre-intervention computed tomography imaging had a significant reduction in the total number of access sites (1.2 versus 1.5; p = 0.03), contrast needed (5.9 versus 8.2 ml/kg; p = 0.008), fluoroscopy (20.7 versus 38.8 minutes; p = 0.02) and procedural time (83.4-128.4 minutes; p = 0.002) for the intervention. There was no significant difference in radiation burden between the groups (p = 0.35). Pre-procedural computed tomography imaging adds value by aiding interventional planning for neonatal patent ductus arteriosus stenting. A statistically significant reduction in the number of access sites, contrast exposure, as well as fluoroscopic and procedural time was noted without significantly increasing the cumulative radiation burden.

ACCAPA: anomalous circumflex coronary artery origin from pulmonary artery.

Anomalous circumflex coronary artery origin from pulmonary artery is a very rare congenital heart disease. Misdiagnosis of this condition may lead to inadequate myocardial protection during cardiopulmonary bypass surgery.

3D advanced imaging overlay with rapid registration in CHD to reduce radiation and assist cardiac catheterisation interventions.

Novel commercially available software has enabled registration of both CT and MRI images to rapidly fuse with X-ray fluoroscopic imaging. We describe our initial experience performing cardiac catheterisations with the guidance of 3D imaging overlay using the VesselNavigator system (Philips Healthcare, Best, NL). A total of 33 patients with CHD were included in our study. Demographic, advanced imaging, and catheterisation data were collected between 1 December, 2016 and 31 January, 2019. We report successful use of this technology in both diagnostic and interventional cases such as placing stents and percutaneous valves, performing angioplasties, occlusion of collaterals, and guidance for lymphatic interventions. In addition, radiation exposure was markedly decreased when comparing our 10-15-year-old coarctation of the aorta stent angioplasty cohort to cases without the use of overlay technology and the most recently published national radiation dose benchmarks. No complications were encountered due to the application of overlay technology. 3D CT or MRI overlay for CHD intervention with rapid registration is feasible and aids decisions regarding access and planned angiographic angles. Operators found intraprocedural overlay fusion registration using placed vessel guidewires to be more accurate than attempts using bony structures.

Association between patient age at implant and outcomes after transcatheter pulmonary valve replacement in the multicenter Melody valve trials.

OBJECTIVES: To investigate whether age and valve size at implant contribute to outcomes after Melody transcatheter pulmonary valve replacement (TPVR). BACKGROUND: Patient age and valve size at implant contribute to longevity of surgical pulmonary valves. METHODS: All patients discharged with a Melody valve in the pulmonary position, as part of three prospective Melody valve multicenter studies, comprised the study cohort. Acute and time-related outcomes were analyzed according to age: children (≤12 years), adolescents (13-18 years), young adults (19-29 years), and older adults (≥30 years). RESULTS: Successful Melody valve implantation occurred in 49 children, 107 adolescents, 96 young adults, and 57 older adults. Pediatric patients (≤18 years) were more likely to have TPVR for conduit stenosis than adults (62% vs. 44%); children had the smallest conduits. After TPVR, pediatric and adult patients had similar decreases in right ventricular (RV) size by MRI, but adults had improved percentage predicted peak VO2 (58% preimplant to 64% postimplant, p = .02) and FEV1 (69% pre to 71% post, p = .005). Younger age was associated with shorter freedom from RVOT dysfunction, reintervention, and explant. Children had the shortest freedom from endocarditis (p = .041), but all other groups had 5-year freedom from endocarditis of ≥90%. CONCLUSIONS: Younger age was associated with shorter time to RVOT dysfunction, reintervention, and explant after Melody TPVR. Patients ≥13 years of age were at low risk for endocarditis and explant to 5 years. A better understanding of time-related outcomes by age will aid in the comparison of therapeutic options for TPVR candidates. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT00740870 (NCT00740870), https://clinicaltrials.gov/ct2/show/NCT01186692 (NCT01186692), and https://clinicaltrials.gov/ct2/show/NCT00688571 (NCT00688571).

Two-dimensional systolic speckle tracking echocardiography provides a noninvasive aid in the identification of acute pediatric heart transplant rejection.

BACKGROUND: Acute rejection is an important cause of morbidity and mortality in the pediatric heart transplant (HT) population. A reliable noninvasive method for diagnosis of clinical rejection could substantially reduce these negative outcomes. OBJECTIVE: Evaluate left ventricular (LV) global longitudinal strain (GLS), and global circumferential strain (GCS) as early noninvasive indicators of acute pediatric HT rejection. METHODS: An 18-month prospective cohort study involving 61 patients evaluated absolute change in peak global systolic strain (GLS and GCS) from enrollment (baseline) to next planned clinical encounter (follow-up) or rejection. Acute rejection defined as a biopsy of grade ≥ 2R or treatment with enhanced immunosuppression by the transplant team, blinded to strain analysis. Two patient cohorts three months post HT without evidence of rejection at enrollment were identified. The study cohort experienced rejection. The control cohort remained free from rejection on follow-up. Two-way analysis of variance (ANOVA) models evaluated change in GLS and GCS by cohort group and time. RESULTS: Applying exclusion criteria, 51 patients enrolled in the control cohort and 10 in the study cohort. The study cohort's mean GLS declined 33% from baseline to rejection (P < .001) and mean GCS declined 16.6% (P = .021). No significant change from baseline to follow-up was seen in the control cohort. A threshold absolute GLS value of 16.1% identified acute rejection with 100% sensitivity and 98% specificity (Likelihood Ratio, [LR] 51). CONCLUSION: Noninvasive global longitudinal strain was sensitive and specific in the identification of acute clinical rejection in pediatric HT recipients.

Initial Experience With the Pediatric Impella Device: A Feasibility Study in a Porcine Model.

OBJECTIVE: This study's objective was to evaluate insertion techniques and device fit of the pediatric version of the Impella ventricular assist device in swine which had similar sized carotids and left ventricles (LVs) as children weighing 10-20 kg. BACKGROUND: Options for minimally invasive circulatory support in children are limited. A modified device based on the current Impella 2.5 platform was created in an effort to provide minimally invasive circulatory support for children. METHODS: Animal studies (n = 10) were performed to determine technical feasibility of device implant via the right common carotid artery (RCCA) in swine with a carotid and LV size similar to children with a BSA < 1 m2 and weight 10-20 kg. The RCCA diameter was measured on pre-implant ultrasound and the LV length was measured at necropsy. The animals were supported for 4 hr and the device explanted. Blood samples and post-explant necropsy was performed to evaluate for device related complications. RESULTS: All animals underwent successful device insertion. Mean carotid artery diameter by ultrasound was 3.5 ± 0.3 mm. There was no LV or aortic/mitral valve damage with a minimum LV length of 5.4 cm. CONCLUSIONS: Minimally invasive circulatory support is needed in small children. Limitations are primarily related to vessel and chamber size. The Impella Pediatric catheter was safely and successfully implanted in carotid arteries similar in size to children weighing 10-20 kg with minimal complications. © 2016 Wiley Periodicals, Inc.

Angiographic Tool to Detect Pulmonary Arteriovenous Malformations in Single Ventricle Physiology.

Background: Individuals with single ventricle physiology who are palliated with superior cavopulmonary anastomosis (Glenn surgery) may develop pulmonary arteriovenous malformations (PAVMs). The traditional tools for PAVM diagnosis are often of limited diagnostic utility in this patient population. We sought to measure the pulmonary capillary transit time (PCTT) to determine its value as a tool to identify PAVMs in patients with single ventricle physiology. Methods: We defined the angiographic PCTT as the number of cardiac cycles required for transit of contrast from the distal pulmonary arteries to the pulmonary veins. Patients were retrospectively recruited from a single quaternary North American pediatric center, and angiographic and clinical data was reviewed. PCTT was calculated in 20 control patients and compared to 20 single ventricle patients at the pre-Glenn, Glenn, and Fontan surgical stages (which were compared with a linear-mixed model). Correlation (Pearson) between PCTT and hemodynamic and injection parameters was assessed using 84 Glenn angiograms. Five independent observers calculated PCTT to measure reproducibility (intra-class correlation coefficient). Results: Mean PCTT was 3.3 cardiac cycles in the control population, and 3.5, 2.4, and 3.5 in the pre-Glenn, Glenn, and Fontan stages, respectively. PCTT in the Glenn population did not correlate with injection conditions. Intraclass correlation coefficient was 0.87. Conclusions: Pulmonary angiography can be used to calculate the pulmonary capillary transit time, which is reproducible between observers. PCTT accelerates in the Glenn stage, correlating with absence of direct hepatopulmonary venous flow.

Transcatheter Device Therapy and the Integration of Advanced Imaging in Congenital Heart Disease.

Transcatheter device intervention is now offered as first line therapy for many congenital heart defects (CHD) which were traditionally treated with cardiac surgery. While off-label use of devices is common and appropriate, a growing number of devices are now specifically designed and approved for use in CHD. Advanced imaging is now an integral part of interventional procedures including pre-procedure planning, intra-procedural guidance, and post-procedure monitoring. There is robust societal and industrial support for research and development of CHD-specific devices, and the regulatory framework at the national and international level is patient friendly. It is against this backdrop that we review transcatheter implantable devices for CHD, the role and integration of advanced imaging, and explore the current regulatory framework for device approval.

Role of Cross-Sectional Imaging in Pediatric Interventional Cardiac Catheterization.

Management of congenital heart disease (CHD) has recently increased utilization of cross-sectional imaging to plan percutaneous interventions. Cardiac computed tomography (CT) and cardiac magnetic resonance (CMR) imaging have become indispensable tools for pre-procedural planning prior to intervention in the pediatric cardiac catheterization lab. In this article, we review several common indications for referral and the impact of cross-sectional imaging on procedural planning, success, and patient surveillance.

Stenting of aortic coarctation: acute, intermediate, and long-term results of a prospective multi-institutional registry--Congenital Cardiovascular Interventional Study Consortium (CCISC).

INTRODUCTION: Since the 1980s, stent implantation has evolved as an important therapeutic strategy for coarctation of the aorta. However, available data is frequently flawed by short follow-up, lack of adequate follow-up imaging, and retrospective nature of data collection. METHODS: Data was prospectively collected using a multicenter registry congenital cardiovascular interventional study consortium (CCISC). Between 2000 and 2009, 302 patients from 34 centers with a median weight of 58 kg underwent stent implantation for coarctation. Eligible patients (44%) completed intermediate follow-up (3-18 months) with integrated imaging (cath, CT, MRI), whereas 21% completed long-term follow-up (>18-60 months). Procedural success was defined as UL/LL systolic gradient of less than 20 mm Hg, lack of significant recurrent obstruction, and freedom from unplanned repeat intervention. RESULTS: Acute procedural success was 96%. Cumulative intermediate success was 86%, and cumulative long-term success was 77%. Unplanned repeat interventions were required in 4%, and aortic wall complications were seen in 1% of patients (dissection n = 1 and aneurysm n = 3). Other adverse events (n = 15) occurred mainly acutely and included technical complications such as stent malposition (n = 9). At long-term follow-up, 23% of patients continued to have systolic blood pressure above the 95th centile, 9% had an upper-to-lower limb blood pressure gradient in excess of 20 mm Hg, and 32% were taking antihypertensive medication. CONCLUSIONS: This study documented acute, intermediate, and long-term outcome data comparable or superior with other surgical or interventional series. However, even with successful initial stent therapy, patients continue to require long-term follow-up and have associated long-term morbidity, relating to aortic wall complications, systemic hypertension, recurrent obstruction as well as need for repeat intervention.

Use of institutional criteria for transcatheter device closure of Fontan fenestration - Midterm outcomes.

BACKGROUND: There are no established criteria to decide suitability for Fontan fenestration closure. Our institution has the following criteria: an unobstructed Fontan pathway with no significant decompressing venovenous collaterals, baseline Fontan pressure ≤15 mmHg, baseline cardiac index ≥2 L/min/m2, and a decrease in cardiac index ≤20% with test occlusion of the fenestration. OBJECTIVE: The objective of the study was to review midterm outcomes following device closure of Fontan fenestration using institutional criteria. MATERIALS AND METHODS: A retrospective review was performed of patients who underwent catheterization with prior fenestrated Fontan procedure between May 2005 and January 2015. Patients were classified as those who underwent successful closure (A), had closure deferred due to failure to meet criteria (B), or were not referred for closure (C). RESULTS: There were 42 patients in Group A, 10 in Group B, and 150 in Group C. The mean Fontan pressure increased from 13.1 ± 2.1 to 14.5 ± 2.1mmHg in Group A and 14.6 ± 1.5 to 15.7 ± 2.2 mmHg in Group B (P = not significant). With test occlusion, cardiac index fell by 18.12% ± 15.68% in Group A and 33.75% ± 14.98% in Group B (P = 0.019). At a median of 46 month follow-up, oxygen saturation increased significantly from 85.15% ± 6.29% at baseline to 94.6% ± 4.43% (P < 0.001) in Group A but with no statistically significant difference in the rates of plastic bronchitis, protein-losing enteropathy, stroke, or heart transplantation between the three groups. CONCLUSIONS: Using institutional criteria, transcatheter device closure of Fontan fenestration was followed by significant increase in oxygen saturations and no statistically significant difference in morbidity or mortality between closure and nonclosure groups.

Simultaneous stent implantation to treat bifurcation stenoses in the pulmonary arteries: Initial results and long-term follow up.

BACKGROUND: Balloon angioplasty of bifurcating pulmonary artery (PA) stenoses is often inadequate, and stent treatment often requires simultaneous implantation of two stents. This study evaluates initial results and long-term follow up of transcatheter stent placement in bifurcating PAs. METHODS: This is a retrospective review of patients (pts) who had bifurcating PA stents placed in main and lobar branches from 1993 to 2007. RESULTS: Forty-nine pts had bifurcating PA stents placed at a median age of 10.9 years (range 1-43 years). The mean minimum vessel diameter increased from 5.7 +/- 2.5 mm to 11.0 +/- 3.6 mm (P < 0.001), the mean gradient across the stenoses decreased from 37.0 +/- 26.9 to 9.2 +/- 13 mm Hg (P < 0.001), whereas the mean RV:FA ratio decreased from 0.76 +/- 0.29 to 0.53 +/- 0.24 (P < 0.001). There was one death due to severe pulmonary hemorrhage. F/U data were available in 38 pts (mean duration 6.3 +/- 4.1 years, range 1.2-13.1 years). Thirty pts underwent repeat catheterizations (mean 2.3 +/- 2.2 years poststent), with 26 requiring further interventions: Fifteen had balloon angioplasty alone and 11 had additional stents placed. There were no complications at f/u catheterization. Six pts underwent further palliative surgeries, although none for repair of branch PA stenoses. CONCLUSIONS: Simultaneous transcatheter placement of bifurcating PA stents provides immediate gradient relief of bifurcating stenoses in the proximal or lobar branch PAs and reduces RV systolic pressure. Further interventions can be safely performed in future procedures, and the presence of stents does not complicate future surgeries.

Invasive Hemodynamics of Adult Congenital Heart Disease: From Shunts to Coarctation.

Adults with congenital heart disease are a growing population with increasingly more complex disease, in large part due to improvements in delivery of care to the pediatric population. Cardiac catheterization is an integral component of diagnosis and management in these patients. Careful attention to detail and a thorough understanding of intracardiac hemodynamics are critical to performing complete diagnostic evaluations. This article outlines the most commonly encountered lesions with guidelines for invasive assessment to help guide further therapy.

Acute and Midterm Outcomes of Transcatheter Pulmonary Valve Replacement for Treatment of Dysfunctional Left Ventricular Outflow Tract Conduits in Patients With Aortopulmonary Transposition and a Systemic Right Ventricle.

BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) is an established therapy for dysfunctional right ventricular (RV) outflow tract conduits. TPVR in patients with congenitally corrected transposition of the great arteries, subpulmonary left ventricle, and left ventricular outflow tract (LVOT) conduit dysfunction has not been studied. Unique anatomic and physiological aspects of this population may contribute to distinct risks and outcomes. METHODS AND RESULTS: Across 10 US centers, 27 patients with a dysfunctional LVOT conduit were evaluated in the catheterization laboratory between December 2008 and August 2015 with the intent to perform TPVR. TPVR was successful in 23 patients (85%). Five serious adverse events occurred in 4 cases (15%), including pulmonary hemorrhage, hypotension requiring vasoactive support, conduit disruption requiring covered stent (n=2), and acute RV dysfunction with flash pulmonary edema. After TPVR, the LVOT peak systolic ejection gradient decreased from median of 35 to 17 mm Hg (P<0.001); pulmonary insufficiency was trivial/none in all but 1 patient, where it was mild. Worsening of systemic RV dysfunction or tricuspid regurgitation was seen in 12 patients (57%) and was associated with a significantly lower post-TPVR LVOT peak systolic ejection gradient (median 17 versus 21 mm Hg; P=0.02) and higher post-TPVR RV sphericity index (median 0.88 versus 0.52; P=0.004). Post-TPVR, there were 2 late deaths because of RV failure and 1 cardiac transplantation because of progressive RV dysfunction and tricuspid regurgitation. CONCLUSIONS: TPVR in dysfunctional LVOT conduits is feasible but associated with an important rate of TPV nonimplantation and procedural serious adverse events. Worsening systemic RV function and tricuspid regurgitation may develop after LVOT TPVR.

Comprehensive assessment of patent ductus arteriosus by echocardiography before transcatheter closure.

BACKGROUND: Anatomic type and angiographic measurements of patent ductus arteriosus (PDA) are used to determine the suitability of transcatheter closure (TCC). The purpose of this study is to evaluate whether these PDA features can be obtained by 2-dimensional echocardiography (2DE). METHODS: We retrospectively compared PDA measurements and type from 36 patients submitted to TCC between November 1995 and October 2000. RESULTS: The patient age ranged between 2 months to 10.5 years (median = 1.2 years). A significant correlation was found between measurements of PDA minimal diameter (R(2) = 0.88) and diameter at aortic ostium (R(2) = 0.72); whereas a poor correlation existed between measurements of the ampulla length. The 2DE and angiographic PDA classification were concordant in 31 of 36 (86%) patients. CONCLUSION: Our data support the use of 2DE measurements of PDA minimal diameter and PDA diameter at the aortic end to assess suitability for TCC. In the majority of cases, PDA type can be diagnosed by 2DE.

Utility of Exercise Testing to Assess Aortic Recoarctation.

Because it is not known how often and how uniformly exercise testing is used to "unmask" recurrent or persistent coarctation of the aorta, this study was designed to determine (a) the frequency with which exercise testing is used by the clinician to evaluate patients after coarctation repair, and (b) the hemodynamic measures obtained with exercise that are considered to be indicative of significant persistent or recurrent coarctation. Questionnaires were sent to 80 randomly selected pediatric cardiologists; 49 were returned completed. About half of the respondents performed exercise testing (ET) on all of their patients after coarctation repair and 75 % tested at least half. Those who supervised an exercise laboratory used ET for a significantly greater number of their patients. In descending order, rest arm-leg gradient (ALG), maximal exercise systolic blood pressure (MXBP), and postexercise ALG were considered the most important indicators of significant recoarctation. The majority of respondents made decisions based on data from the ET that were consistent with published guidelines.