M ore than 50 years after its contemporary description, hypertrophic cardiomyopathy (HCM) remains the most common cause of sudden death in the young. [1][2][3][4][5][6] Although several clinical markers have proved to be useful guides for risk stratification, 3-5,7 current strategies do not identify all HCM patients at risk for sudden death. 3,5,8,9 Over the last Background-Hypertrophic cardiomyopathy (HCM) is the most common cause of sudden death in the young, although not all patients eligible for sudden death prevention with an implantable cardioverter-defibrillator are identified. Contrast-enhanced cardiovascular magnetic resonance with late gadolinium enhancement (LGE) has emerged as an in vivo marker of myocardial fibrosis, although its role in stratifying sudden death risk in subgroups of HCM patients remains incompletely understood. Methods and Results-We assessed the relation between LGE and cardiovascular outcomes in 1293 HCM patients referred for cardiovascular magnetic resonance and followed up for a median of 3.3 years. Sudden cardiac death (SCD) events (including appropriate defibrillator interventions) occurred in 37 patients (3%

Background— Genotyping in hypertrophic cardiomyopathy has gained increasing attention in the past decade. Its major role is for family screening and rarely influences decision-making processes in any individual patient. It is associated with substantial costs, and cost-effectiveness can only be achieved in the presence of high-detection rates for disease-causing sarcomere protein gene mutations. Therefore, our aim was to develop a score based on clinical and echocardiographic variables that allows prediction of the probability of a positive genotype. Methods and Results— Clinical and echocardiographic variables were collected in 471 consecutive patients undergoing genetic testing at a tertiary referral center between July 2005 and November 2010. Logistic regression for a positive genotype was used to construct integer risk weights for each independent predictor variable. These were summed for each patient to create the Toronto hypertrophic cardiomyopathy genotype score. A positive genotype was found in 163 of 471 patients (35%). Independent predictors with associated-risk weights in parentheses were as follows: age at diagnosis 20 to 29 (−1), 30 to 39 (−2), 40 to 49 (−3), 50 to 59 (−4), 60 to 69 (−5), 70 to 79 (−6), ≥80 (−7); female sex (4); arterial hypertension (−4); positive family history for hypertrophic cardiomyopathy (6); morphology category (5); ratio of maximal wall thickness:posterior wall thickness <1.46 (0), 1.47 to 1.70 (1), 1.71 to 1.92 (2), 1.93 to 2.26 (3), ≥2.27 (4). The model had a receiver operator curve of 0.80 and Hosmer–Lemeshow goodness-of-fit P =0.22. Conclusions— The Toronto genotype score is an accurate tool to predict a positive genotype in a hypertrophic cardiomyopathy cohort at a tertiary referral center.