ABC | Volume 112, Nº1, January 2019

Elias Nero et al ARVC/D - Diagnosis and treatment Arq Bras Cardiol. 2019; 112(1):91-103 Review Article Figure 3 – Proposed scheme for the prognostic stratification of patients with ARVC/D , according to the clinical presentation. The risk subgroups shown in the figure were defined based on the estimated probability of a major arrhythmic event (sudden cardiac death, cardiac arrest due to ventricular fibrillation, ventricular tachycardia or an event requiring ICD intervention) during follow-up, in relation to arrhythmic events or previous risk factors. An estimated annual risk of more than 10% defines the high-risk group; a risk between 1% and 10% defines the intermediate risk group; and a risk below 1% defines the low-risk group. VEx: ventricular extrasystoles; ARVC/D: cardiomyopathy/right ventricular arrhythmogenic dysplasia. Adapted from Corrado et al., 2017. 5 Major arrythimic events Cardiac arrest due to ventricular fibrilation Sustained ventricular tachycardia Major risk factors Unexplained syncope Non-sustained ventricular tachycardia Severe RV and/or LV dysfunction Minor risk factors Probands, male gender Frequent Vex (≥ 1000/24h) Inductibility in the electrophysiological study T waves negative beyond V3 Amount of fibrous-fatty tissue in the RV Multiple mutaions of desmosomal genes Absence of events or risk factors Healthy genetic mutation carriers for ARVC/D High Risk > 10%/year Intermediate risk 1-10%/year Low risk <1%/year ranges from 0.08% to 3.6% per year. In community studies, which provide real-world data, annual mortality is < 1%. 4,5 Several factors were proposed for stratification of mortality risk and / or ventricular tachyarrhythmias in the ARVC/D. Corrado et al. 34 developed a risk stratification categorized as high, intermediate and low risk. Thus, the authors sought to facilitate the early recognition of individuals who would benefit from ICD implantation (Figure 3). 4,34 The main clinical variables considered as independent predictors of worse evolutionary prognosis are: arrhythmic malignant events (SAD, cardiac arrest due to VF, appropriate intervention of ICD, or therapy of ICD for fast VT/VF); heart transplantation; and in some studies, unexplained syncope. 5 Other criteria, such as the result of genetic mapping and the invasive electrophysiological study, are still controversial in the literature. 5 Treatment The most important goals of treating patients with ARVC/D include: • Reduction in mortality from arrhythmic SAD or death from heart failure. • Prevention of disease progression with consequent RV, LV or biventricular dysfunction and heart failure. • Improvement of symptoms and quality of life by means of reduction/abolition of palpitations, VT relapses, or discharges from ICD (appropriate or inappropriate). • Limitation of symptoms of heart failure and increased functional capacity. Therapeutic options consist of lifestyle changes, pharmacological treatment, catheter ablation, ICD, and cardiac transplantation. 1,6,7 Available evidence indicates that family members with a negative phenotype (carriers of healthy genes or with an unknown genotype) do not require any specific treatment other than sports restriction. 5 Lifestyle change Competitive sports activity increases the risk of SAD by two to five times in adolescents and young adults with ARVC/D. 25 In a recent study, Ruwald et al. have established a link between SAD and intense effort in young individuals with ARVC/D. The authors followed 108 probands and demonstrated that competitive sports practice is associated with a significant increase in the VT/death combined outcome, and early phenotypic manifestation when compared to the inactivity of sedentary patients, or to the practice of recreational sports. 15 Another finding was that the earliest start of competitive sports is associated with the early onset of clinical symptomatology. 15 Early identification, prior to the symptomatic phase, of athletes affected by preparatory screening for the onset of physical activity and their disqualification from competitive sports activity may “save lives” (Italian experience). 34 It is postulated that myocyte intercellular adhesion impairment can lead to tissue and organ vulnerability with 8