Prognostic role of stress echocardiography in hypertrophic cardiomyopathy: The International Stress Echo Registry

BackgroundStress echo (SE) may have a role in the outcome in patients with hypertrophic cardiomyopathy (HCM).ObjectivesThe aim was to assess the prognostic value of SE in a retrospective multicenter study in HCM.MethodsWe enrolled 706 HCM patients. The employed stress was exercise (n = 608) and/or vasodilator (n = 146, dipyridamole in 98 and adenosine in 48). We defined SE positivity according to clinical/hemodynamic criteria including: symptoms (all stress modalities), exercise-induced hypotension (failure to increase or fall > 20 mm Hg, exercise) and exercise-induced left ventricular outflow tract obstruction (left ventricular outflow tract obstruction > 50 mm Hg); and ischemic criteria, such as new wall motion abnormalities (new wall motion abnormality) and/or reduction of coronary flow reserve velocity (CFVR ≤ 2.0) on left anterior descending coronary artery with vasodilator stress assessed in 116 patients. All patients completed the clinical follow-up.ResultsPositive SE showed more frequently CFVR reduction, exercise-induced hypotension, left ventricular outflow tract obstruction, and symptoms (38, 23, 20 and 15% respectively), but new wall motion abnormality only in 6%. During a median follow-up of 49 months 180 events were observed, including 40 deaths. Clinical/hemodynamic criteria did not predict outcome (X2 0.599, p = 0.598), whereas ischemia-related SE criteria (X2: 111.120, p < 0.0001) was significantly related to outcome. Similarly, mortality was predicted with SE ischemic-criteria (X2 16.645, p < 0.0001).ConclusionsSE has an important prognostic significance in HCM patients, with ischemia-related end-points showing greater predictive accuracy than hemodynamic endpoints. New wall motion abnormalities and impairment of CFVR should be specifically included in SE protocols for HCM.