Myocardial contraction fraction predicts mortality for patients with hypertrophic cardiomyopathy.

The myocardial contraction fraction (MCF: stroke volume to myocardial volume) is a novel volumetric measure of left ventricular myocardial shortening. The purpose of the present study was to assess whether MCF could predict adverse outcomes for HCM patients. A retrospective cohort study of 438 HCM patients was conducted. The primary and secondary endpoints were all-cause mortality and HCM-related mortality. The association between MCF and endpoints was analysed. During a follow-up period of 1738.2 person-year, 76 patients (17.2%) reached primary endpoint and 50 patients (65.8%) reached secondary endpoint. Both all-cause mortality rate and HCM-related mortality rate decreased across MCF tertiles (24.7% vs. 17.9% vs. 9.5%, P trend = 0.003 for all-cause mortality; 16.4% vs. 9.7% vs. 6.1%, P trend = 0.021 for HCM-related mortality). Patients in the third tertile had a significantly lower risk of developing adverse outcomes than patients in the first tertile: all-cause mortality (adjusted HR: 0.26, 95% CI: 0.12-0.56, P = 0.001), HCM-related mortality (adjusted HR: 0.17, 95% CI: 0.07-0.42, P < 0.001). At 1-, 3-, and 5-year of follow-up, areas under curve were 0.699, 0.643, 0.618 for all-cause mortality and 0.749, 0.661, 0.613 for HCM-related mortality (all P value < 0.001), respectively. In HCM patients, MCF could independently predict all-cause mortality and HCM-related mortality, which should be considered for overall risk assessment in clinical practice.