Exercise echocardiography and cardiac magnetic resonance imaging to predict outcome in patients with hypertrophic cardiomyopathy

Abstract

Aims: We have observed that wall motion abnormalities (WMAs) during exercise echocardiography (ExE) are associated to events in hypertrophic cardiomyopathy (HCM). Our objective was to evaluate ExE and cardiac magnetic resonance (CMR) to predict outcome in HCM.

Methods and results: ExE and CMR were performed in 148 patients with HCM. During follow-up (7.1 ± 2.7 years), there were 7 hard events (Hard-E) and 26 combined events (Comb-E). Exercise WMAs were observed in 13 patients (8.8%), perfusion defects in 10 (6.8%), and late gadolinium enhancement (LGE) in 48 (32.4%). WMAs were seen in 57% of patients with Hard-E vs. 6% without (P = 0.001) and in 23 and 6% with and without Comb-E (P = 0.005). Perfusion defects were also more frequent in patients with Hard-E than without (43 vs. 5%, P = 0.007) and in patients with Comb-E than without (23 vs. 5%, P = 0.002). LGE (g) was greater in patients with Comb-E than without [median (25th-75th percentile) 0 (0-21.1) vs. 0 (0-9.3) g P = 0.04]. Univariable predictors of Comb-E included NYHA class ≥2, peak double product, ΔWMSI, and CMR data. Peak double product [Hazard ratios (HR) = 0.99, confidence intervals (CI) 95% 0.99-0.99, P = 0.02] and ΔWMSI (HR = 404, CI 95% 12-13681, P = 0.001) remained independent predictors. Peak WMSI correlated with myocardial mass with LGE (r = 0.20, P = 0.02) and with perfusion defect area (r = 0.40, P < 0.001). LGE affecting ≥15% of the left ventricle was observed in 38% of patients with exercise WMAs vs. 12% without (P = 0.009).

Conclusion: CMR data are associated to exercise WMAs in patients with HCM. ExE and CMR may help to predict outcome in them.

Keywords: cardiac magnetic resonance; exercise echocardiography; hypertrophic cardiomyopathy; regional wall motion abnormalities.