LAUSR

H ypertrophic cardiomyopathy (HCM) is the most common genetic heart disease, affecting 1 in 500 individuals and is associated with an increased risk of sudden cardiac death (SCD) and heart failure (1). With contemporary management strategies including implantable cardioverter-defibrillators (ICDs) in patients at increased risk of SCD and other therapies, including medications, myectomy, alcohol septal ablation, and heart transplantation in appropriate patients, the prognosis for HCM has improved over the last several decades (2). However, risk stratification remains a significant challenge (1) and selecting patients appropriately for ICD therapy can be problematic. The U.S. and European approaches to SCD risk stratification in HCM have some important differences. Clearly identified risk factors in the most recent U.S. guidelines include: 1) personal history of aborted SCD, ventricular fibrillation, or sustained ventricular tachycardia; 2) family history of SCD; and 3) syncope (3). Markers with less robust evidence behind them include nonsustained ventricular tachycardia on monitoring, extreme increase in left ventricular (LV) wall thickness (>30 mm), and hypotensive response to exercise (3). A European consortium more recently developed a HCM Risk-SCD Calculator that includes variables such as age, extent