François Marcotte

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.

Pulmonary Arterial Hypertension in Patients With Transcatheter Closure of Secundum Atrial Septal Defects A Longitudinal Study

Background—Pulmonary arterial hypertension (PAH) may develop in patients with atrial septal defects (ASD); however, little is known about associated risk factors and its evolution after transcatheter ASD closure. Methods and Results—We conducted a cohort study on 215 adults with attempted transcatheter ASD closure from 1999 to 2006. Patients were classified according to baseline systolic pulmonary artery pressures as having no (I, <40 mm; Hg), mild (II, 40 to 49 mm; Hg), moderate (III, 50 to 59 mm; Hg), or severe (IV, ≥60 mm; Hg) PAH. Independent predictors of moderate or severe PAH were older age (odds ratio [OR], 1.10 per year; P<0.0001), larger ASD (OR, 1.13 per millimeter; P=0.0052), female sex (OR, 3.9; P=0.0313), and at least moderate tricuspid regurgitation (OR, 3.6; P=0.0043). At 15 (interquartile range, 8 to 43) months post–ASD closure, patients with higher baseline pressures were more likely to experience a ≥5-mm; Hg decrease (33.7%, 73.9%, 79.2%, and 100.0% in groups I to IV, P<0.0001), with a larger magnitude of reduction (0, 8, 17, and 22 mm; Hg; P<0.0001). However, normalization of pressures (<40 mm; Hg) occurred less frequently in patients with more advanced PAH (90.2%, 71.7%, 66.7%, and 23.5%, P<0.0001). Among patients with moderate or severe PAH, independent predictors of normalization were lower baseline pressures (OR, 0.91 per mm; Hg; P=0.0418) and no more than mild tricuspid regurgitation (OR, 0.14; P=0.0420). Conclusion—In adults with ASDs, severity of PAH is modulated by age, sex, defect size, and degree of tricuspid regurgitation. Patients with moderate or severe PAH may benefit from substantial reductions in pulmonary artery pressures after transcatheter ASD closure, although the PAH values remain elevated in a sizeable proportion.

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.

Cardiac Magnetic Resonance Assessment of Myocarditis

Symptoms consistent with myocarditis are a frequent cause of medical visits, especially in young and middleaged patients. Moreover, myocarditis was found to be the most frequent disease in patients with acute coronary syndrome yet normal coronary arteries. 1 Although many causes have been identified, acute cases are mostly because of myocardial involvement in systemic viral disease. 2,3 During the first days of viral myocarditis, there is direct cardiomyocyte injury, accompanied by edema, necrosis, and, depending on its spatial extent, regional, or even global contractile dysfunction. The tissue is typically cleared from the virus within 5 days; yet, reactive inflammation (clean-up) may last for several weeks. In uncomplicated disease, there is full tissue and functional recovery within 3 to 4 weeks, whereas more severe disease necrosis results in myocardial scarring. Prolonged autoimmune response or virus persistence may lead to chronic inflammation and is considered a frequent cause of dilated cardiomyopathy. 3 Symptoms are not specific; patients may present with chest pain, fatigue, dyspnea, or arrhythmia. ECG findings may include AV block, ventricular or supraventricular arrhythmia, and ST changes, including severe elevation mimicking acute myocardial infarction. Except for more severe cases, echocardiography typically shows normal systolic wall motion or just mild regional dysfunction. Serological markers for cardiomyocyte injury, such as troponin, may be normal. Because of the nonspecificity of its symptoms, signs and test findings, myocarditis is often diagnosed by exclusion of other cardiac diseases. The specific identification of an active nonischemic inflammatory process, therefore, is a clinical challenge, especially in patients presenting with acute chest pain and heart failure. Invasive endomyocardial biopsy is only recommended in patients with evidence for heart failure in combination with acute disease (<2 weeks, class I) or left ventricular dilatation (<3 months, class I) or specific other cases of heart failure (class IIa). 4 While nuclear imaging methods have not been proven useful, echocardiography and contrast-enhanced cardiovascular magnetic resonance (CMR) are standard imaging tools in patients with suspected myocarditis. Figures 1 to 3 present results of a 31-year-old male patient presenting with acute chest pain and a normal physical examination. Although ECG, coronary angiography, and echocardiography were either normal or nonspecific, CMR provided strong evidence for myocardial edema, hyperemia, and necrosis and thus allowed for establishing the diagnosis of acute myocarditis.

Prediction of complications in pregnant women with cardiac diseases referred to a tertiary center

BACKGROUND Prediction of adverse maternal and neonatal events in women with heart disease is not well established. We aimed to assess cardiac, obstetrical and neonatal complications in pregnant women with heart disease referred to our tertiary care center and validate a previously proposed risk index. METHODS We included 227 women with cardiac disease followed for 312 pregnancies at our tertiary center from 1992 to 2007. Cardiac risk was assessed using the previously proposed Cardiac Disease in Pregnancy (CARPREG) score and its association with maternal and neonatal outcomes was determined. RESULTS Maternal cardiac lesions were predominantly congenital (81.4%). CARPREG risk was low (score=0) in 66.3% and intermediate (score=1) in 33.7% pregnancies. Maternal cardiac events complicated 7.4% pregnancies, with pulmonary edema occurring most frequently (3.8%). An intermediate score was associated with a higher rate of cardiac events (19.0% vs. 1.4%, odds ratio [OR] 15.6, 95% confidence interval (95%CI) 4.5-54.4, p<0.0001). Adverse events occurred in 27.5% neonates. Preterm deliveries occurred in 16.7% pregnancies, more commonly in patients with intermediate scores (OR 2.4, 95%CI 1.2-4.6, p=0.01). The sensitivity and negative predictive values of a low score were respectively 87% and 99% for total cardiac events and both 100% for primary cardiac events including pulmonary edema and sustained arrhythmia. CONCLUSION The CARPREG risk index has a high sensitivity and negative predictive value with regards to cardiac complications in pregnant women with heart disease. It may, therefore, be routinely used to improve the assessment of cardiac risk before and during pregnancy.

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.

Evaluation of Adult Congenital Heart Disease by Cardiac Magnetic Resonance Imaging

Cardiovascular magnetic resonance (CMR) imaging plays an essential role in the evaluation and follow-up of adult congenital heart disease (ACHD), providing safe, high-resolution imaging of some of the most complex anatomies encountered. Unlimited by acoustic windows and capable of tissue characterization, CMR is devoid of ionizing radiation and provides superior three-dimensional spatial resolution to transthoracic echocardiography and superior temporal resolution to computed tomography, making it the gold standard for various cardiac and great vessel imaging indications in ACHD. In this state-of-the art review, we provide an overview of CMR examination methods and detail the various approaches and classical findings in the more common forms of ACHD. Although this review touches upon technical aspects of CMR imaging in ACHD, it is primarily geared toward the adult congenital caregiver (i.e., clinical, interventional, or surgical), highlighting relevant practical considerations. To enhance the clinical utility of this review, numerous examples with intraoperative correlates are provided to highlight our imaging approaches for various defects. As CMR image acquisition may be time consuming and requires patient collaboration (e.g., intermittent breath holding), a systemic approach is required to maximize efficiency. A thorough knowledge of ACHD anatomy and natural history is essential in maximizing image interpretation. Proficient scanning is further enabled by clearly outlined study objectives with prior documentation of interventional and surgical procedures, where applicable.

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.

Thromboprophylaxis for atrial arrhythmias in congenital heart disease: A multicenter study

BACKGROUND There is a paucity of data to guide decisions regarding thromboprophylaxis for atrial arrhythmias in congenital heart disease. METHODS A retrospective multicenter cohort study enrolled patients with documented sustained atrial arrhythmias and congenital heart disease from 12 North American centers to quantify thromboembolic and bleeding rates associated with antiplatelet and anticoagulation therapy, and explore associated factors. A blinded committee adjudicated all qualifying arrhythmias and outcomes. RESULTS A total of 482 patients, 45.2% female, age 32.0±18.0years, were followed for 11.3±9.4years since the qualifying arrhythmia. Antiplatelet therapy was administered to 37.8%, anticoagulation to 54.4%, and neither to 7.9%. Congenital heart disease complexity was simple, moderate, and severe in 18.5%, 34.4%, and 47.1%, respectively. Freedom from thromboembolic events was 84.7±2.7% at 15years, with no difference between anticoagulation versus antiplatelet therapy (P=0.97). Congenital heart disease complexity was independently associated with thromboembolic events, with rates of 0.00%, 0.93%, and 1.95%/year in those with simple, moderate, and severe forms (P<0.001). CHADS2 and CHA2DS2-VASc scores were not predictive of thromboembolic risk. Annualized bleeding rates with antiplatelet and anticoagulation therapy were 0.66% and 1.82% (P=0.039). In multivariable analyses, anticoagulation [hazard ratio (HR) 4.76, 95% CI (1.05-21.58), P=0.043] and HAS-BLED score [HR 3.15, 95% CI (1.02, 9.78), P=0.047] were independently associated with major bleeds. CONCLUSION Current management of atrial arrhythmias in congenital heart disease is associated with a modest rate of thromboembolic events, which is predicted by disease complexity but not CHADS2/CHA2DS2-VASc scores. HAS-BLED score is applicable to the congenital population in predicting major bleeds.

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.