François-Pierre Mongeon

Prevalence of Left Ventricular Systolic Dysfunction in Adults With Repaired Tetralogy of Fallot

Left ventricular (LV) systolic dysfunction has been observed in patients with repaired tetralogy of Fallot (TOF), although its clinical associations are unknown. Adults with repaired TOF were identified from 11 adult congenital heart disease centers. Clinical history was reviewed. Patients with pulmonary atresia were excluded. Echocardiograms were reanalyzed to estimate LV ejection fraction. LV function was defined as normal (LV ejection fraction ≥ 55%) or mildly (45% to 54%), moderately (35% to 44%), or severely (< 35%) decreased. Right ventricular (RV) and LV dimensions and Doppler parameters were remeasured. Function of all valves was qualitatively scored. Of 511 patients studied, LV systolic dysfunction was present in 107 (20.9%, 95% confidence interval 17.4 to 24.5). Specifically, 74 (14.4%) had mildly decreased and 33 (6.3%) had moderately to severely decreased systolic function. Presence of moderate to severe LV dysfunction was associated with male gender, LV enlargement, duration of shunt before repair, history of arrhythmia, QRS duration, implanted cardioverter-defibrillator, and moderate to severe RV dysfunction. Severity or duration of pulmonary regurgitation was not different. In conclusion, LV systolic dysfunction was found in 21% of adult patients with TOF and was associated with shunt duration, RV dysfunction, and arrhythmia.

Risk stratification in surgically repaired tetralogy of Fallot.

Tetralogy of Fallot is the most common form of congenital heart disease in implantable cardioverter–defibrillator (ICD) recipients. Indeed, sudden death of presumed arrhythmic etiology is the most frequent mode of demise in patients with surgically repaired tetralogy of Fallot, often in early-to-mid adulthood. Nevertheless, the overall annual incidence of sudden death is actually low. Therein lies the major challenge of risk stratification. This review highlights some of the complexities involved in risk stratifying patients with tetralogy of Fallot, underscoring the importance of avoiding oversimplification by means of a rigid algorithm that dictates therapy. To complement sound clinical judgment, a quantitative probabilistic approach is presented, which considers the body of literature from primary prevention ICD trials, risk factors identified by observational studies, the value of programmed ventricular stimulation and insights gleaned from studying ICD recipients with tetralogy of Fallot.

Fontan Circulation: Success or Failure?

Fontan surgery represents a milestone in the evolution of congenital heart disease management. It achieved the seemingly improbable (ie, restoration of a noncyanotic state by entirely bypassing the subpulmonary ventricle). In so doing, it has allowed a generation of children who may have otherwise succumbed to their severe congenital heart defect to survive to adulthood. Perfect univentricular physiology is, however, an elusive goal. The Fontan circulation inherently represents a hemodynamic compromise that results in a catalog of potential multiorgan complications. In this review, we explore current knowledge regarding pathophysiology of the failing Fontan, its varied clinical manifestations, and potential therapeutic options. Failure of the Fontan circulation is broadly divided into 3 overlapping categories: ventricular dysfunction, systemic complications of Fontan physiology, and chronic Fontan failure. As long as the Fontan operation continues to serve as the paradigm of care for patients with univentricular hearts, efforts must be directed toward supporting this dynamic circulation that progressively declines in efficiency with age. Continued research in therapies is needed for univentricular dysfunction and systemic complications of Fontan palliation, including potential uses of mechanical support as a bridge to transplantation or as a neosubpulmonary ventricle. Fontan patients remain a major challenge to the medical and surgical community as a whole. Multicentre and multidisciplinary efforts to improve the density and depth of experiences might lead to a better appreciation for, and management of, Fontan failure and its ramifications.

Adult congenital heart disease: a growing epidemic.

Medical and surgical breakthroughs in the care of children born with heart defects have generated a growing population of adult survivors and spawned a new subspecialty of cardiology: adult congenital heart disease. The prevalence of adult congenital heart disease is escalating at a rampant rate, outpacing the relatively static prevalence of pediatric congenital heart disease, because adults now surpass children in numbers by a ratio of 2:1. As such, congenital heart disease can no longer be considered primarily a pediatric specialty. Most congenital heart defects are not curable and require lifelong specialized care. Health care systems worldwide are challenged to meet the unique needs of this increasingly complex patient population, including the development of supraregional centres of excellence to provide comprehensive and multidisciplinary specialized care. In this review, we explore the incidence and prevalence of congenital heart disease and their changing patterns, address organization and delivery of care, highlight the importance of appropriate training and dedicated research, summarize the high burden of health care resource utilization, and provide an overview of common issues encountered in adults with congenital heart disease.

Risks and Benefits of Exercise Training in Adults With Congenital Heart Disease

Exercise capacity in adults with various forms of congenital heart disease is substantially lower than that of the general population. Although the underlying congenital heart defect, and its sequelae, certainly contribute to observed exercise limitations, there is evidence suggesting that deconditioning and a sedentary lifestyle are important implicated factors. The prevalence of acquired cardiovascular comorbidities is on the increase in the aging population with congenital heart disease, such that obesity and a sedentary lifestyle confer increased risk. Health fears and misconceptions are common barriers to regular physical activity in adults with congenital heart disease, despite evidence linking lower functional capacity to poor outcomes, and data supporting the safety and efficacy of exercise in bestowing numerous physical and psychosocial rewards. With few exceptions, adults with congenital heart disease should be counselled to exercise regularly. In this contemporary review, we provide a practical approach to assessing adults with congenital heart disease before exercise training. We examine available evidence supporting the safety and benefits of exercise training. Risks associated with exercise training in adults with congenital heart disease are discussed, particularly with regard to sudden cardiac death. Finally, recommendations for exercise training are provided, with consideration for the type of congenital heart disease, the nature (ie, static vs dynamic) and intensity (ie, low, medium, high) of the physical activity, and associated factors such as systemic ventricular dysfunction and residual defects. Further research is required to determine optimal exercise regimens and to identify effective strategies to implement exercise training as a key determinant of healthy living.

Exercise Testing and Stress Imaging in Valvular Heart Disease

The role of exercise testing and stress imaging in the management of patients with valvular heart disease (VHD) is reviewed in this article. The American College of Cardiology/American Heart Association and the European Society of Cardiology/European Association of Cardiothoracic Surgery have recently put emphasis on the role of exercise testing to clarify symptom status and the use of stress imaging to assess the dynamic component of valvular abnormalities and unmask subclinical myocardial dysfunction that could be missed at rest. Recent studies have demonstrated the incremental prognostic value of exercise echocardiography for asymptomatic patients with severe aortic stenosis, moderate-severe mitral stenosis, and severe primary mitral regurgitation. In patients with low-flow, low-gradient aortic stenosis, dobutamine stress echocardiography is recommended to differentiate true severe from pseudosevere aortic stenosis. Data on the prognostic value of stress echocardiography in aortic regurgitation and functional mitral regurgitation are less robust. Data are sparse on the use of stress imaging in right-sided VHD, however recent studies using stress cardiovascular magnetic resonance imaging offer some prognostic information. Although the strongest recommendations for surgical treatment continue to be based on symptom status and resting left ventricular repercussions, stress imaging can be useful to optimize risk stratification and timing of surgery in VHD. Randomized clinical trials are required to confirm that clinical decision-making based on stress imaging can lead to improved outcomes.

Pregnancy in women with Fontan physiology

Advances in the care of patients with a univentricular heart have enabled the majority to survive well into adulthood. Consequently, an increasing number of women with Fontan palliation are contemplating pregnancy. This review summarizes physiologic modifications related to pregnancy in the setting of single-ventricle physiology, discusses potential maternal cardiovascular concerns and describes commonly encountered obstetrical and neonatal complications. Management issues are addressed, including counseling, anesthetic considerations and the need for multidisciplinary specialized care.

Early results of extra-aortic annuloplasty ring implantation on aortic annular dimensions.

OBJECTIVES Dilatation of the aortic annulus is a cause of recurrent aortic regurgitation following the Ross or Yacoub procedures. Use of an extra-aortic annuloplasty ring is a potentially useful adjunct procedure. The aim of this study was to analyze the early effectiveness and mid-term stability of this surgical approach. METHODS From 2011 to 2015, 50 patients (mean age, 43 ± 14 years) underwent adjunct extra-aortic annuloplasty ring implantation (n = 39 Dacron rings and n = 11 ExAo rings [CORONEO Inc, Montreal, Canada]). Median ring size was 28 mm (range, 27-32 mm). All patients had aortic regurgitation or a dilated aortic annulus. Concomitant surgical procedure was a valve-sparing remodeling procedure (n = 32) or a Ross procedure (n = 18). Baseline and follow-up echocardiographic systolic and diastolic aortic annular dimensions were prospectively collected. Longitudinal analyses were performed using mixed-effect models. Median follow-up was 12 months (98% complete). RESULTS Use of an extra-aortic annuloplasty ring resulted in a significant decrease in both systolic (27.9 ± 0.5 mm preoperatively vs 23.6 ± 0.3 mm at discharge, P < .001) and diastolic (24.8 ± 0.4 mm preoperatively vs 20.3 ± 0.3 mm at discharge, P < .001) dimensions. Mean systolic and diastolic dimensions remained statistically unchanged up to 2 years postoperatively, compared with their predischarge values. Systolic expansion of the annulus was conserved early after surgery (16% systolic expansion) and preserved up to 2 years after ring implantation. CONCLUSIONS Use of an extra-aortic annuloplasty ring is effective at reducing annular diameters. This remains stable at mid-term follow-up, with preservation of aortic annular dynamics. Longer-term studies are required to determine the continued stability and impact on long-term clinical outcomes.

Multimodality Noninvasive Imaging of Thoracic Aortic Aneurysms: Time to Standardize?

Aortic imaging is an essential part of a surveillance program for patients with a confirmed or suspected aortopathy because aortic size is crucial for predicting the risk of death, aortic rupture, or aortic dissection. Noninvasive aortic imaging relies on transthoracic and transesophageal echocardiography, cardiovascular magnetic resonance and computed tomography (CT) imaging. Echocardiography and cardiovascular magnetic resonance offer comprehensive anatomical and functional evaluation of the heart, aortic valve, and aorta, and CT is more limited to anatomical data. However, CT is fast, available, and less operator-dependent. There is general consensus that the aorta should be measured at reproducible anatomical landmarks on electrocardiogram-gated images, perpendicular to the blood flow and using multiplanar reconstruction if possible. The method of measurement must be included in the clinical report. Normal aortic size depends on age, sex, and body size. Serial measurements should use identical methods. There is controversy about the inclusion of the aortic wall in the vessel diameter and the trigger time in the cardiac cycle for measurement, although diastole is more reproducible. The best method to measure the diameter of the sinuses of Valsalva remains unclear. Imagers and clinicians should pay close attention to the aorta measurement techniques and weigh the clinical implications of modification of their institutional protocols.

The impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot

BACKGROUND Sudden death of presumed arrhythmic etiology is the leading cause of mortality in adults with tetralogy of Fallot. OBJECTIVES To assess the impact of exercise on ventricular arrhythmias in adults with tetralogy of Fallot. METHODS Adults with repaired tetralogy of Fallot were randomized in a 2:1 ratio to an open-label trial of standard care versus 12weeks of supervised combined aerobic/resistance training with continuous Holter monitoring. Proportion of premature ventricular complexes (PVC) and runs of non-sustained ventricular tachycardia (NSVT) were assessed by mixed and Poisson regression models with generalized estimating equations for repeated measures. RESULTS A total of 152 Holters were performed in 17 patients, median age 35 (interquartile range [IQR] 28, 42) years, 65% male, 13 of whom were randomized to exercise training. Baseline characteristics were similar between groups. Exercise training resulted in significant increases in peak oxygen uptake (11±19%, p=0.028), metabolic equivalents (11±18%, p=0.027), and exercise duration (8±10%, p=0.009) compared to no changes in controls. Frequent (≥30 per hour) PVCs were present in 46% of patients, couplets in 62%, and 3 to 7 beat runs of NSVT in 31%. The median proportion of PVCs was 1.93‰ (IQR 0.41, 5.89) at baseline and 1.45‰ (IQR 0.08, 2.76) during the initial exercise session (p=0.722), and remained stable over time (ß coefficient=-0.031, p=0.408). Runs of NSVT decreased significantly over time (ß coefficient=-0.032, p=0.018). CONCLUSION In adults with repaired tetralogy of Fallot, exercise training is safe, improves exercise capacity, and appears to confer a beneficial effect on ventricular arrhythmias.