Prognostic significance of cardiac magnetic resonance parameters in hypertrophic cardiomyopathy: a multicentre study.

Hypertrophic cardiomyopathy (HCM) patients have an increased risk of heart failure (HF), arrhythmias and sudden cardiac death (SCD). There are a lack of studies comparing the prognostic value of cardiac magnetic resonance (CMR) determined left ventricular (LV) global longitudinal strain (LVGLS), left atrial strain (LAS), and late gadolinium enhancement (LGE). This retrospective study aims to identify the significant independent predictor(s) of MACE in patients with HCM. HCM patients who underwent CMR examinations between 2008 and 2022 at 5 medical sites were recruited. CMR feature-tracking (FT) was used to determine LV strain (LVS) and LAS. LGE was quantified. Primary outcome was a composite outcome of MACE (i.e., HF hospitalisation, cardiac arrest and all-cause mortality). Univariate and multivariate Cox regression analyses included clinical parameters, HCM features, medications, LVS, LAS and LGE. Kaplan-Meier analyses with log-rank tests were performed. 468 patients (308 males, median age of 64) were included. 147 patients experienced MACE with a median follow-up of 7.6 years. Patients with MACE had smaller LVGLS (- 8.03% vs - 10.05%; p < 0.001), as well as smaller left atrial reservoir strain (LASr) (15.13% vs 23.13%; p < 0.001), left atrial conduit strain (LAScd), and left atrial booster strain (LASb) (8.885 vs 12.57%; p < 0.001). However, LGE quantification showed no significant difference (9.76% vs 8.92%; p < 0.535). On Kaplan-Meier analysis, all LVS and LAS parameters were significantly associated with MACE (p < 0.001), while only LVGLS and LAS parameters were significantly associated with all-cause mortality. On multivariable Cox regression analysis, all three LAS parameters were significant independent predictors of the composite outcome (p <0.05). LVS parameters were no longer significant on multivariable Cox regression. LASr, LAScd and LASb are significant independent predictors of MACE in CMR for assessing prognosis in HCM patients. LGE quantification was not a significant independent predictor.