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Background The Long-ter M O U tcomes after the Multisystem Inflammatory S yndrome I n C hildren (MUSIC) study aims to characterize the frequency and time course of acute and long-term cardiac and non-cardiac sequelae in multisystem inflammatory syndrome in children associated with COVID-19 (MIS-C), which are currently poorly understood. Methods This multicenter observational cohort study will enroll at least 600 patients Conclusion The MUSIC study, with the largest cohort of MIS-C patients and the longest follow-up period to date, will make an important contribution to our understanding of the acute cardiac and non-cardiac manifestations of MIS-C and the long-term effects of this public health emergency.

Background Randomized controlled trials (RCTs) in children with heart disease are challenging and therefore infrequently performed. We sought to improve feasibility of perioperative RCTs for this patient cohort using data from a large, multicenter clinical registry. We evaluated potential enrollment and end point frequencies for various inclusion cohorts and developed a novel global rank trial end point. We then performed trial simulations to evaluate power gains with the global rank end point and with use of planned covariate adjustment as an analytic strategy. Methods Data from the Society of Thoracic Surgery-Congenital Heart Surgery Database (STS-CHSD, 2011-2016) were used to support development of a consensus-based global rank end point and for trial simulations. For Monte Carlo trial simulations (n = 50,000/outcome), we varied the odds of outcomes for treatment versus placebo and evaluated power based on the proportion of trial data sets with a significant outcome (P Results The STS-CHSD study cohort included 35,967 infant index cardiopulmonary bypass operations from 103 STS-CHSD centers, including 11,411 (32%) neonatal cases and 12,243 (34%) high-complexity (Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery mortality category ≥4) cases. In trial simulations, study power was 21% for a mortality-only end point, 47% for a morbidity and mortality composite, and 78% for the global rank end point. With covariate adjustment, power increased to 94%. Planned covariate adjustment was preferable to restricting to higher-risk cohorts despite higher event rates in these cohorts. Conclusions Trial simulations can inform trial design. Our findings, including the newly developed global rank end point, may be informative for future perioperative trials in children with heart disease.

Background The Fontan procedure is the final step of the 3-stage palliative procedure commonly performed in children with single ventricle physiology. Thrombosis remains an important complication in children after this procedure. To date, guideline recommendations for the type and duration of thromboprophylaxis after Fontan surgery are mainly based on extrapolation of knowledge gained from adults at risk for thrombosis in other clinical settings. Warfarin is being used off-label, and because of its multiple interactions with other drugs and food, a new alternative is highly desirable. Rivaroxaban, a direct Factor Xa inhibitor with a predictable pharmacokinetic profile, is a candidate to address this medical need. Study design The UNIVERSE study is a prospective, open-label, active-controlled, multicenter study in children 2 to 8 years of age who have single ventricle physiology and had the Fontan procedure within the 4 months preceding enrollment. This study consists of 2 parts. In Part A, rivaroxaban pharmacokinetics, pharmacodynamics, safety, and tolerability are assessed to validate the pediatric dosing selected. In Part B, safety and efficacy of rivaroxaban versus acetylsalicylic acid are evaluated for thromboprophylaxis in children post–Fontan procedure. Children in each part will receive study drug for 12 months. Part A has been completed with 12 children enrolled. Enrollment into Part B is currently ongoing. Conclusions The UNIVERSE study aims to provide dosing, pharmacokinetics/pharmacodynamics, safety, and efficacy information on the use of rivaroxaban, an oral anticoagulant, versus acetylsalicylic acid, an antiplatelet agent, in children with single ventricle physiology after the Fontan procedure.

For decades, physicians have administered corticosteroids in the perioperative period to infants undergoing heart surgery with cardiopulmonary bypass (CPB) to reduce the post-operative systemic inflammatory response to CPB. Some question this practice because steroid efficacy has not been conclusively demonstrated and because some studies indicate that steroids could have harmful effects. STRESS is a randomized, placebo-controlled, double blind, multi-center trial designed to evaluate safety and efficacy of perioperative steroids in infants (age < 1 year) undergoing heart surgery with CPB. Participants (planned enrollment = 1200) are randomized 1:1 to methylprednisolone (30mg/kg) administered into the CPB pump prime versus placebo. The trial is nested within the existing infrastructure of the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD). The primary outcome is a global rank score of mortality, major morbidities and hospital length of stay with components ranked commensurate with their clinical severity. Secondary outcomes include several measures of major post-operative morbidity, post-operative hospital length of stay and steroid-related safety outcomes including prevalence of hyperglycemia and post-operative infectious complications. STRESS will be one of the largest trials ever conducted in children with heart disease and will answer a decades old question related to safety and efficacy of perioperative steroids in infants undergoing heart surgery with CPB. The pragmatic “trial within a registry” design may provide a mechanism for conducting low cost, high efficiency trials in a heretofore-understudied patient population. Trial Registration Number

Development of pediatric medications and devices is complicated by differences in pediatric physiology and pathophysiology (both compared with adults and within the pediatric age range), small patient populations, and practical and ethical challenges to designing clinical trials. This article summarizes the discussions that occurred at a Cardiac Safety Research Consortium-sponsored Think Tank convened on December 10, 2010, where members from academia, industry, and regulatory agencies discussed important issues regarding pediatric cardiovascular safety of medications and cardiovascular devices. Pediatric drug and device development may use adult data but often requires additional preclinical and clinical testing to characterize effects on cardiac function and development. Challenges in preclinical trials include identifying appropriate animal models, clinically relevant efficacy end points, and methods to monitor cardiovascular safety. Pediatric clinical trials have different ethical concerns from adult trials, including consideration of the subjects' families. Clinical trial design in pediatrics should assess risks and benefits as well as incorporate input from families. Postmarketing surveillance, mandated by federal law, plays an important role in both drug and device safety assessment and becomes crucial in the pediatric population because of the limitations of premarketing pediatric studies. Solutions for this wide array of issues will require collaboration between academia, industry, and government as well as creativity in pediatric study design. Formation of various epidemiologic tools including registries to describe outcomes of pediatric cardiac disease and its treatment as well as cardiac effects of noncardiovascular medications, should inform preclinical and clinical development and improve benefit-risk assessments for the patients. The discussions in this article summarize areas of emerging consensus and other areas in which consensus remains elusive and provide suggestions for additional research to further our knowledge and understanding of this topic.

Background Mitral regurgitation is the most common indication for reoperation in children following repair of atrioventricular septal defect (AVSD). We hypothesized that angiotensin-converting enzyme inhibitor therapy would decrease the severity of mitral regurgitation and limit left ventricular volume overload in children following AVSD repair. Methods The Pediatric Heart Network designed a placebo-controlled randomized trial of enalapril in this population. The primary aim was to test the effect of enalapril on the change in left ventricular end-diastolic dimension body surface area–adjusted z score. Before the launch of the trial, a feasibility study was performed to estimate the number of patients with at least moderate mitral regurgitation following AVSD repair. Trial experience Seventeen months after the start of the study, 349 patients were screened, 8 were trial eligible, and only 5 were enrolled. The study was subsequently terminated because of low patient accrual. Several factors led to the problems with patient accrual, including (1) the use of criteria to assess disease severity in the feasibility study that were not identical to those used in the trial, (2) failure to achieve equipoise for the study among clinicians and referring physicians, (3) reliance on methodology developed in adult populations with different disease mechanisms, and (4) absence of adequate data to define the natural history of the disease process under study. Progress in the treatment of children with cardiovascular disease will depend on the future of multicenter collaborative clinical trials. The lessons learned from this study may contribute to improvements in this research.

Background Wyman W. Lai, MD, MPH, and Victoria L. Vetter, MD, MPH. The Pediatric Heart Network (PHN), funded under the U.S. National Institutes of Health–National Heart, Lung, and Blood Institute (NIH–NHLBI), includes two Clinical Research Skills Development (CRSD) Cores, which were awarded to The Children's Hospital of Philadelphia and to the Morgan Stanley Children's Hospital of New York–Presbyterian. To provide information on how to develop a clinical research career to a larger number of potential young investigators in pediatric cardiology, the directors of these two CRSD Cores jointly organized a one-day seminar for fellows and junior faculty from all of the PHN Core sites. The participants included faculty members from the PHN and the NHLBI. The day-long seminar was held on April 29, 2009, at the NHLBI site, immediately preceding the PHN Steering Committee meeting in Bethesda, MD. Methods The goals of the seminar were 1) to provide fellows and early investigators with basic skills in clinical research 2) to provide a forum for discussion of important research career choices 3) to introduce attendees to each other and to established clinical researchers in pediatric cardiology, and 4) to publish a commentary on the future of clinical research in pediatric cardiology. Results The following chapters are compilations of the talks given at the 2009 PHN Clinical Research Skills Development Seminar, published to share the information provided with a broader audience of those interested in learning how to develop a clinical research career in pediatric cardiology. The discussions of types of clinical research, research skills, career development strategies, funding, and career management are applicable to research careers in other areas of clinical medicine as well. Conclusions The aim of this compilation is to stimulate those who might be interested in the research career options available to investigators.

Background The use of clinical registries and administrative data sets in pediatric cardiovascular research has become increasingly common. However, this approach is limited by relatively few existing datasets, each of which contain limited data, and do not communicate with one another. We describe the implementation and validation of methodology using indirect patient identifiers to link The Society of Thoracic Surgeons Congenital Heart Surgery (STS-CHS) Database to The Pediatric Health Information Systems (PHIS) Database (a pediatric administrative database). Methods Centers submitting data to STS-CHS and PHIS during 2004 to 2008 were included (n = 30). Both data sets were limited to patients 0 to 18 years old undergoing cardiac surgery. An exact match was defined as an exact match on each of the following: date of birth, date of admission, date of discharge, sex, and center. Likely matches were defined as an exact match for all variables except ±1 day for one of the date variables. Results Of 45,830 STS-CHS records, 87.4% matched to PHIS using the exact match criteria and 90.3% using the exact or likely match criteria. Validation in a subset of patients revealed that 100% of exact and likely matches were true matches. Conclusions This analysis demonstrates that indirect identifiers can be used to create high-quality link between a clinical registry and administrative data set in the congenital heart surgery population. This methodology, which can also be applied to other data sets, allows researchers to capitalize on the strengths of both types of data and expands the pool of data available to answer important clinical questions.

Background Congress has authorized the United States Food and Drug Administration (FDA) to provide industry sponsors with a 6-month extension of drug marketing rights under the Pediatric Exclusivity Provision if FDA-requested pediatric drug trials are conducted. The cost and economic return of pediatric exclusivity to industry sponsors has been shown to be highly variable. We sought to determine the cost of performing pediatric exclusivity trials within a single therapeutic area and the subsequent economic return to industry sponsors. Methods We evaluated 9 orally administered antihypertensive drugs submitted to the FDA under the Pediatric Exclusivity Provision from 1997 to 2004 and obtained key elements of the clinical trial designs and operations. Estimates of the costs of performing the studies were generated and converted into after-tax cash outflow. Market sales were obtained and converted into after-tax inflows based on 6 months of additional patent protection. Net economic return and net return-to-cost ratios were determined for each drug. Results Of the 9 antihypertensive agents studied, an average of 2 studies per drug was performed, including at least 1 pharmacokinetic study and a safety and efficacy study. The median cost of completing a pharmacokinetic trial was $862,000 (range $556,000 to 1.8 million). The median cost of performing safety and efficacy trials for these agents was $4.3 million (range $2.1-12.9 million). The ratio of net economic return to cost was 17 (range 4-64.7). Conclusion We found that, within a cohort of antihypertensive drugs, the Pediatric Exclusivity Provision has generated highly variable, yet lucrative returns to industry sponsors.

Background Cardiovascular disease, including aortic root dilation, dissection, and rupture, is the leading cause of mortality in patients with Marfan syndrome (MFS). The maximal aortic root diameter at the sinuses of Valsalva is considered the best predictor of adverse cardiovascular outcome. Although advances in therapy have improved life expectancy, affected individuals continue to suffer cardiovascular morbidity and mortality. Recent studies in an FBN1 -targeted mouse model of MFS with aortic disease similar to that seen in humans showed that treatment with losartan normalized aortic root growth and aortic wall architecture. Methods The Pediatric Heart Network designed a randomized clinical trial to compare aortic root growth and other short-term cardiovascular outcomes in subjects with MFS receiving atenolol or losartan. Individuals 6 months to 25 years of age with a body surface area–adjusted aortic root z score >3.0 will be eligible for inclusion. The primary aim is to compare the effect of atenolol therapy with that of losartan therapy on the rate of aortic root growth over 3 years. Secondary end points include progression of aortic regurgitation; incidence of aortic dissection, aortic root surgery, and death; progression of mitral regurgitation; left ventricular size and function; echocardiographically derived measures of central aortic stiffness; skeletal and somatic growth; and incidence of adverse drug reactions. Conclusion This randomized trial should make a substantial contribution to the management of individuals with MFS and expand our understanding of the mechanisms responsible for the aortic manifestations of this disorder.

Background The Best Pharmaceuticals for Children Act provides a 6-year extension to the economic incentives offered to drug manufacturers under the Pediatric Exclusivity Provision, for providing requested information on drugs used in children, which includes >50 oral antihypertensive medications. Guidelines were published outlining specific requirements for the design and analysis of trials to provide the requested information. Methods We review the design and analysis requirements, along with recruitment and eligibility guidelines, for dose-ranging studies of oral antihypertensives in children in light of ethical and methodologic issues unique to pediatric research. We also discuss examples of trials conducted to date and the implications and limitations of legislative efforts. Results Four possible trial types are outlined in the guidelines. Trial C, which uses a randomized withdrawal phase after treatment, has been used most often. Avoidance of a true placebo arm may enhance patient recruitment and minimize ethical concerns at the expense of a more complicated design and analysis. In addition, this trial involves little risk for manufacturers because patent extension does not depend on the outcome of the trial. Conclusions Studies being conducted under the Pediatric Exclusivity Provision will provide valuable information concerning dosing and efficacy for several antihypertensive medications used in children. New legislation may stimulate study of drugs without remaining patent life, but data on safety, long-term outcomes, and the youngest pediatric age groups are also needed for a full understanding of all issues pertinent to pediatric use. (Am Heart J 2002;144:608-14.)

In 2007, the American Heart Association recommended cessation of antibiotic prophylaxis for infective endocarditis (IE) before dental procedures for all but those at highest risk for adverse outcomes from IE. The impact of these guidelines is unclear. We evaluated IE hospitalizations at US children's hospitals during this period.Children18 years old hospitalized from 2003 to 2010 with IE at 37 centers in the Pediatric Health Information Systems Database were included. Using Poisson regression, we evaluated the number IE hospitalizations over time (raw and indexed to total hospital admissions).A total of 1157 IE cases were identified; 68% had congenital heart disease (CHD). The raw number of IE cases did not change significantly over time (+1.6% difference post vs pre guidelines, 95% CI -6.4% to +10.3%, P = .7). When the number of IE cases was indexed per 1,000 hospital admissions, there was a significant decline during the time period before the guidelines (annual change: -5.9%, 95% CI -9.9 to -1.8, P = .005) and a similar decline in the post guidelines period such that the difference between the 2 periods was not significant (P = .15). In subgroup analysis, no significant change over time in IE cases (raw or indexed) was found in the CHD subset, those 5 to 18 years old (subgroup most likely receiving dental care), or in cases coded as oral streptococci.We found no evidence that release of new antibiotic prophylaxis guidelines was associated with a significant change in IE admissions across 37 US children's hospitals.

Background Angiotensin converting enzyme (ACE) inhibitors are known to improve clinical outcome and ventricular function in adults with heart failure. Infants with single-ventricle physiology show abnormalities in ventricular function as well as poor growth. The ability of an ACE inhibitor to preserve ventricular function and improve growth in these infants is unknown. Methods The Pediatric Heart Network designed a randomized, double-blind trial to compare outcomes in infants with single-ventricle physiology receiving enalapril or placebo. Neonates ≤45 days old were eligible. The primary outcome is weight-for-age Z -score at 14 months of age. Secondary outcomes include other measures of somatic growth, laboratory and functional measures of heart failure, developmental indices, measures of ventricular size and function, and the relationship of the renin-angiotensin-aldosterone system genotype to the response to enalapril. The incidence and spectrum of adverse events will also be compared between treatment groups. Results A total of 1,245 neonates were screened and 533 (43%) were eligible. The consent rate was 43%; 230 subjects were enrolled. Parental reluctance to participate was the primary reason for non-consent in 79% of the eligible nonconsenting patients. Randomized patients were older, more likely to be male, and more likely to have hypoplastic left heart syndrome than the eligible patients who did not enroll. Conclusions The results of this randomized trial will make an important contribution to the management of infants with single-ventricle physiology by determining whether initiation of ACE inhibition therapy in the neonatal period improves growth, clinical outcome, and ventricular function.

Background Few antihypertensive therapies have been systematically studied in children and dosages for many agents are either extrapolated from adult studies or obtained from small homogenous pediatric populations. It is well established that adult patients of different races show disparate response to angiotensin-converting enzyme (ACE) inhibitors, however no such studies have been performed in children. Methods Two hundred fifty three children ages 6-16 with hypertension or with high normal blood pressure with an associated medical condition requiring antihypertensive therapy were enrolled at 78 clinical sites in the US, Russia, and Israel in a double blind study to evaluate the efficacy of fosinopril compared to placebo. Results The racial composition of the cohort included 60.1% white (152/253), 20.6% black (52/253), 13.8% Hispanic (35/253), 2.0% Asian (5/253), 0.4% Native American (1/253), and 3.2% (8/253) children classified as other or of mixed race. After adjusting for baseline blood pressure and body surface area (BSA) there was no significant dose response seen in non-black patients. Non-blacks randomized to the low, medium, and high dosages of fosinopril all had a mean decrease of 12 mm Hg in their sequential systolic BP (SBP). Blacks, however, demonstrated a significant dose response to fosinopril; those who received the low dosage had a 5 mm Hg decrease in SBP, and those who received the high dosage had a mean 13 mm Hg decrease in SBP. Conclusions Fosinopril was effective in treating hypertension, but black children required a higher dose per body weight in order to achieve adequate control. This suggests that black children treated with fosinopril for hypertension on average require higher doses to achieve adequate systolic blood pressure control that non-black children.

Increase in vascular permeability and multiorgan dysfunction after cardiopulmonary bypass (CPB) are barriers to successful cardiac surgery in infants. Complement inhibition with TP10, a C3/C5 convertase inhibitor (AVANT Immunotherapeutics, Needham, Mass), blunts post-CPB organ dysfunction in the neonatal pig. Methods and results The pharmacokinetics and safety of TP10 in infants (age1 year, n = 15) undergoing CPB were examined in a phase I/II open-label prospective trial. TP10 (10 mg/kg) was given intravenously before CPB and also added (10 mg/100 mL prime volume) to the CPB circuit. TP10 plasma levels correlated with C3a levels and measures of clinical course. All infants survived. No adverse events were attributed to TP10. TP10 plasma concentration fell toor =60 microg/mL 12 hours after CPB. A 2-compartment model was fit to the TP10 blood levels as a function of time. Based on this model, an initial dose of 10 mg/kg over 0.5 hours followed by 10 mg/kg over 23.5 hours is the most appropriate for maintaining TP10 concentration between 100 microg/mL and 160 microg/mL for 24 hours after CPB. C3a was lower 12 hours after CPB than before CPB and still lower 24 hours after CPB. TP10 concentration was inversely correlated with the 12-hour post-CPB to pre-CPB ratio of C3a (Spearman rho -0.76, P = -.016), and with total (rho -0.56, P =.047) and net (rho -0.85, P =.0016) fluid and blood product administration/kg24 hours after CPB.TP10 administration to infants appears safe. Pharmacokinetic analysis generated an optimal dosing strategy to achieve effective TP10 levels for 24 hours after CPB. In the infant, TP10 appears to decrease CPB-induced complement activation and protect vascular function. These results support a phase III trial of TP10 in infants requiring CPB.

ClinicalTrials.gov is an National Institutes of Health-sponsored registry of federally and privately funded trials. We sought to determine fundamental characteristics of registered pediatric cardiovascular trials (PCVTs).A data set including 68,134 interventional clinical trials was downloaded from ClinicalTrials.gov and entered into a relational database. Aggregate data from PCVTs were compared with other trial specialties. Multivariable logistic regression was used to evaluate factors associated with improved trial quality metrics including blinding and randomization.Between July 1, 2005, and September 27, 2010, 5035 (7%) registered trials targeted pediatric populations, including 213 PCVTs (4.2%), 1,176 pediatric infectious disease trials (23%), 664 pediatric mental health trials (13%), and 346 pediatric hematology/oncology trials (7%). Median (interquartile range) PCVT enrollment was 65 subjects (36-186) and median study duration was 2.3 years (1.3-3.7). The most common PCVTs targeted acquired diseases including hypertension (n = 41, 14%), obesity (n = 26, 9%), pulmonary hypertension (n = 25, 9%), and dyslipidemia (n = 19, 7%). Important factors associated with improved quality metrics included National Institutes of Health as opposed to industry funding (OR, 1.9; P.0001); trial location (trials with both US and foreign enrollment vs trials with US only or foreign only enrollment, P = .02) and trials restricted to younger children as opposed to trials including adolescents (OR, 1.4; P.0001).PCVTs represent a small proportion of clinical trials relative to other pediatric subspecialties. Most PCVTs tend to parallel adult morbidities while there is a relative paucity of trials focused on congenital heart disease. These data may be useful to stakeholders in informing decisions regarding the conduct of PCVTs, and to provide insight into mechanisms to advance PCVT infrastructure.

Background Although transesophageal echocardiography (TEE) is more sensitive than transthoracic echocardiography (TTE) in detecting echocardiographic evidence of infective endocarditis (IE), the impact of TEE on the clinical diagnosis of IE has not been clearly delineated. Methods and Results We studied 112 patients with 114 suspected episodes of IE over a 6-year period who underwent both TTE and TEE during their diagnostic evaluation. Using the results of these studies along with clinical and microbiologic data, we attempted to determine the incremental value of TEE to the Duke Endocarditis Diagnostic Criteria. Patients were initially classified into a diagnostic category of the Duke criteria with TTE data, and then the diagnostic classification was reconsidered with TEE data. A diagnostic category reassignment occurred in 25 of 114 episodes of IE evaluated when TEE results were incorporated into the evaluation with the Duke criteria (22 patients were reclassified from possible IE to definite IE whereas 3 patients were reclassified from rejected to possible IE). Diagnostic reclassification occurred in 9 (11%) of the 80 episodes of suspected IE with native cardiac valves and 13 (34%) of 34 episodes with prosthetic cardiac valves. Most patients reclassified from possible IE to definite IE with TEE data (19 of 22) had an intermediate clinical likelihood of IE, whereas 92% of patients had negative TTE results. Pathologic examination of valvular tissue in 22 of the 114 episodes of suspected IE revealed that the positive predictive value of the Duke criteria with TEE data for diagnosis of IE was 85% in patients with native valves and 89% in patients with prosthetic valves. Conclusions When clinical evidence of IE is present, TEE improves the sensitivity of the Duke criteria to diagnose definite IE. TEE data appears to be especially useful for the diagnostic evaluation of patients with suspected IE who have prosthetic valves. (Am Heart J 2000;139:945-51.)

Abnormal height and adiposity are observed after the Fontan operation. These abnormalities may be associated with worse functional outcome.We analyzed data from the National Heart, Lung, and Blood Institute Pediatric Heart Network cross-sectional study of Fontan patients. Groups were defined by height (z-score-1.5 or≥-1.5) and body mass index (body mass index [BMI] z-score-1.5 or -1.5 to 1.5 or≥1.5). Associations of anthropometric measures with measurements from clinical testing (exercise, echocardiography, magnetic resonance imaging) were determined adjusting for demographics, anatomy, and pre-Fontan status. Relationships between anthropometric measures and functional health status (FHS) were assessed using the Child Health Questionnaire.Mean age of the cohort (n=544) was 11.9±3.4 years. Lower height-z patients (n=124, 23%) were more likely to have pre-Fontan atrioventricular valve regurgitation (P=.029), as well as orthopedic and developmental problems (both P.001). Lower height-z patients also had lower physical and psychosocial FHS summary scores (both P.01). Higher BMI-z patients (n=45, 8%) and lower BMI-z patients (n=53, 10%) did not have worse FHS compared to midrange BMI-z patients (n=446, 82%). However, higher BMI-z patients had higher ventricular mass-to-volume ratio (P=.03) and lower % predicted maximum work (P=.004) compared to midrange and lower BMI-z patients.Abnormal anthropometry is common in Fontan patients. Shorter stature is associated with poorer FHS and non-cardiac problems. Increased adiposity is associated with more ventricular hypertrophy and poorer exercise performance, which may have significant long-term implications in this at-risk population.