Atrial and ventricular mechanical dysfunction and myocardial injury predict long-term outcomes in hypertrophic cardiomyopathy: a retrospective cohort study.

Background: Left ventricular (LV) diastolic dysfunction is a hallmark of hypertrophic cardiomyopathy (HCM) and imposes chronic pressure overload on the left atrium, leading to progressive atrial remodeling and functional impairment. Conventional left atrial (LA) volumetric indices reflect comparatively advanced structural alterations and are incapable of identifying early functional deterioration. The present research sought to investigate the prognostic significance of LA and LV myocardial deformation parameters obtained from cardiovascular magnetic resonance (CMR) in patients with HCM. Methods: This single-center retrospective study included 126 HCM patients and 40 healthy volunteers who underwent comprehensive CMR examinations. LA longitudinal strain (reservoir, conduit, and booster components) was assessed using the fast long-axis method; LV global strain and torsion were derived using feature-tracking analysis. Late gadolinium enhancement (LGE) was quantified to assess myocardial fibrosis. Patients with HCM were followed longitudinally for the occurrence of major adverse cardiovascular events (MACEs). Cox regression analyses were performed to identify independent predictors of MACEs. Results: Compared with healthy volunteers, patients with HCM exhibited significantly impaired LA reservoir, conduit, and booster strain, as well as reduced LV global strain parameters (all P<0.05). Following a median observational period of 1,055 days, 41 patients (32.5%) experienced MACEs. Patients with MACEs demonstrated markedly reduced LA strain and LV torsion compared with those without events. In multivariable Cox regression analysis, LA booster strain [hazard ratio (HR): 0.854, 95% confidence interval (CI): 0.799-0.914], LV torsion (HR: 0.517, 95% CI: 0.298-0.895), and serum creatine kinase myocardial band (CKMB) (HR: 1.032, 95% CI: 1.018-1.047) emerged as independent predictors of MACEs. LA booster strain yielded the optimal prognostic efficacy for predicting MACEs [area under the curve (AUC): 0.827]. Conclusions: LA booster strain, LV torsion, and CKMB represent complementary markers reflecting atrial function, ventricular mechanics, and myocardial injury, respectively. Their independent associations with adverse outcomes highlight the multifactorial nature of disease progression in HCM and support a more integrative approach to risk stratification beyond single-domain assessment. Incorporating these parameters into routine CMR and clinical evaluation may facilitate earlier identification of patients at increased risk for MACEs and support individualized surveillance strategies.