0372: Impact of exercise mitral regurgitation on hypertrophic cardiomyopathy outcomes

International audience; Background Rest echocardiography plays a role in the diagnosis and risk stratification of hypertrophic cardiomyopathy (HCM). Indeed, left atrial enlargement, severe left ventricle (LV) hypertrophy and rest LV outflow tract (LVOT) gradients ≥50mmHg are sudden cardiac death risk factors as highlighted in recent guidelines. Conversely, exercise echocardiography findings play only a limited role in prognosis evaluations. Therefore, we sought to determine whether exercise induced changes in myocardial and valvular functions could improve HCM risk stratification. Methods and results Consecutive HCM patients with a preserved LV ejection fraction underwent standardized exercise echocardiography (including the assessment of myocardial function, dynamic left intra-ventricular gradient and valvular regurgitations) at baseline and were clinically followed for a median of 29.3 months. The primary endpoint was a composite criterion that included death from any cause, cardiorespiratory arrest, and hospitalization for a cardiovascular event. A total of 126 patients were included. Eighteen patients reached the primary endpoint. According to univariate Cox regression analysis, exercise LVOT gradient ≥50mmHg (HR=3.31, p=0.01) and significant (≥2/4) exercise mitral regurgitation (HR=3.64, p