CMR assessment and clinical outcomes of hypertrophic cardiomyopathy with or without ventricular remodeling in the end-stage phase

Abstract

End-stage phase of hypertrophic cardiomyopathy (ES-HCM) is a recognized part of HCM disease spectrum. Information on cardiac magnetic resonance (CMR) studies for ES-HCM especially for those without ventricular remodeling has been limited. We aimed to evaluate the morpho-functional and tissue features of ES-HCM with or without ventricular remodeling and to explore CMR prognostic value in these patients. We analysed CMR scans of sixty-three ES-HCM patients and divided them into those with ventricular dilatation (D-ES, n = 41) and those with normal ventricular size (N-ES, n = 22). Cox proportional hazards models were used to assess the association between CMR parameters and outcomes. Patients in D-ES showed hypokinetic-dilated HCM phenotype, while patients in N-ES showed hypokinetic-restrictive HCM phenotype. LGE extent was significantly larger in D-ES (34.7% ± 15.4% vs. 22.8% ± 7.7%; P < 0.01). Atrial fibrillation and edema of lower extremity were more common in N-ES (72.7 vs. 29.3% and 54.5 vs. 24.4%, respectively; P < 0.05). Log-rank test found no significant difference between 2 groups in combined end point of cardiovascular events (χ² = 0.66, P = 0.418). In multivariate analysis, LGE (HR 1.57-1.83 per 10% LGE increase, P < 0.01) and indexed left atrial volume (LAVI) (HR 1.14-1.21 per 20 mL/m² increase, P < 0.05) remained independently associated with combined end point when adjusted by other risk factors. The CMR features of HCM in end-stage span between two extremes. LGE is more extensive in those with ventricular remodeling and LAVI is larger in those with normal ventricular size. Both LGE and LAVI are significant predictors of poor outcomes.

Keywords: CMR; HCM; Heat failure; Late gadolinium enhancement.