Comprehensive stress echocardiography in hypertrophic cardiomyopathy

Funding Acknowledgements Type of funding sources: None. OnBehalf Stress Echo 2020 study group of the Italian Society of Echocardiography and Cardiovascular Imaging Background Stress echocardiography (SE) in hypertrophic cardiomyopathy (HCM) has more to offer beyond dynamic left ventricular outflow obstruction (LVOTO) to capture the functional heterogeneity of the disease. Objectives To determine the feasibility of comprehensive SE in HCM. Methods We prospectively enrolled 235 HCM patients (age = 48 ± 15 years, 113 men) assessed with exercise stress echocardiography (ESE) in 4 centers. ESE modality was semi-supine bicycle in 29 patients in one center, and treadmill in 206 (followed by same-day, same session, adenosine for step D) in another centers. During SE, we assessed stress-induced new regional wall motion abnormalities (RWMA, step A), coronary flow velocity reserve (CFVR) in left anterior descending coronary artery with Doppler (step D) by semi-supine exercise or adenosine, heart rate reserve (peak/rest heart rate) for EKG-based step E, mitral regurgitation (MR) flow for step F, and LVOTO (step G for gradient). A comprehensive SE score was generated from 0 (all parameters normal) to 5 (all abnormal). Results Technical success rate was 100% for all steps, except step D (80% with semi-supine, 100% with adenosine after treadmill) and F (232/235, 99%). Extra-analysis time was < 3 minutes for steps A + D + E + F + G. Rate of abnormal results ranged from 73% for step E (peak/rest heart rate reserve < 1.80) to 1% for step A (inducible RWMA), with intermediate values for step D (CFVR < 2.0, 44%), step F (at least moderate MR, 32%) and step G (LVOTG > 50 mm Hg, 26%): see figure. SE score was 0 in 14 pts (6%), 1 or 2 in 202 patients (86%) and ≥ 3 in 19 patients (8%). Conclusions Comprehensive SE is feasible in HCM with single stress (semi-supine exercise) or hybrid treadmill exercise followed by adenosine for step D. Phenotyping of the multiform manifestations of HCM with a personalized functional blueprint is now possible. Abstract Figure.