Left ventricular deformation and tissue characteristics in hypertrophic cardiomyopathy patients with HFpEF: a CMR study.

PURPOSE: This study aimed to evaluate left ventricular (LV) deformation and tissue characteristics using cardiac magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM) and heart failure with preserved ejection fraction (HFpEF), to examine their associations with heart failure status, and to explore the correlations between CMR parameters and the H2FPEF score. METHODS: This retrospective study included 105 patients with HCM who underwent 3.0-T CMR. Participants were classified into HFpEF (n = 46) and non-HF (n = 59) groups according to the 2019 ESC HFA-PEFF algorithm. Global radial strain (GRS), global circumferential strain (GCS), global longitudinal strain (GLS), and corresponding systolic and early-diastolic strain rates were derived using CMR feature tracking. Myocardial tissue characterization included native T1 and T2 mapping, extracellular volume fraction (ECV), and late gadolinium enhancement (LGE). Group differences were assessed with t-tests or chi-square tests. Associations between strain, tissue parameters, and the H2FPEF score were evaluated using Spearman correlations. Multivariable logistic regression was performed to identify independent CMR predictors of HFpEF. RESULTS: Compared with non-HF patients, those with HCM-HFpEF showed significantly reduced LV systolic and early-diastolic strain rates, including sGRSr (P = 0.010), sGCSr (P = 0.044), sGLSr (P = 0.018), and eGLSr (P = 0.006). They also demonstrated a higher prevalence and greater extent of LGE, as well as elevated native T1 and ECV values (all P < 0.05). Strain parameters correlated significantly with tissue characteristics (native T1 and mean ECV), except for GCS and ECV. In multivariable analysis, drinking, atrial fibrillation, lower LV-eGLSr, and higher ECV in segments with maximal wall thickness were independently associated with HCM-HFpEF. The H₂FPEF score showed weak but significantly correlations with native T1, ECV, and T2 values in both global and hypertrophied myocardial segments (r = 0.199-0.252, all P < 0.05). CONCLUSIONS: HCM patients with HFpEF exhibit both systolic and diastolic dysfunction, accompanied by increased diffuse and focal fibrosis. Independent predictors of HFpEF include lower LV-eGLSr, higher segmental ECV, atrial fibrillation, and drinking. The H2FPEF score shows significant associations with tissue-level abnormalities, highlighting the complementary role of CMR-derived strain and tissue characterization in the early detection and risk stratification of HFpEF in HCM.