Global longitudinal diastolic strain rate as a novel marker for predicting adverse outcomes in hypertrophic cardiomyopathy by cardiac magnetic resonance tissue tracking

AIM: To examine the prognostic value of global peak diastolic strain rate (PDSR) derived from cardiac magnetic resonance (CMR) tissue tracking (CMR-TT) in predicting adverse outcomes in hypertrophic cardiomyopathy (HCM) patients. MATERIALS AND METHODS: A total of 98 patients diagnosed with HCM (44 patients had left ventricle [LV] outflow tract obstruction [LVOTO] and 54 patients did not) were enrolled and followed for the specified endpoint. LV global myocardial mechanics was assessed in all participants using CMR-TT at study entry. RESULTS: Compared with the non-obstructive subgroup, the obstructive subgroup demonstrated deteriorated magnitude of LV global radial, circumferential, and longitudinal PDSR (all p<0.05). After a mean follow-up period of 4.5 years, 24 patients reached an endpoint before the end of the study. Furthermore, when using the specified cut-off value (0.33 1/s) of longitudinal PDSR, the Kaplan-Meier curve demonstrated that patients with lower longitudinal PDSR had a significantly lower freedom from major adverse cardiovascular events (MACE) compared with their counterparts in the non-obstructive, obstructive, and overall cohorts (all log-rank p<0.05). Multivariable analysis showed that longitudinal PDSR remained the strongest predictor of outcome after adjusting for baseline and CMR variables (hazard ratio, 2.65; 95% confidence interval, 2.21-11.44; p<0.05). CONCLUSION: CMR-TT-derived longitudinal PDSR is probably considered a novel and easyto-perform marker for predicting adverse outcomes in HCM patients, which is beneficial to risk stratification. Further confirmatory studies are needed. (C) 2020 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.