Integrated Use of Late Gadolinium Enhancement and Left Ventricular Global Longitudinal Strain in Hypertrophic Cardiomyopathy.

Background: Late gadolinium enhancement (LGE) and left ventricular global longitudinal strain (LV-GLS) are structural and functional left ventricular remodeling markers in hypertrophic cardiomyopathy (HCM).

Objectives: This study investigated the prognostic value of integrating both markers for risk stratification in HCM.

Methods: Consecutive patients with HCM who underwent CMR between 2008 and 2020 at 2 tertiary hospitals were retrospectively analyzed. LGE% and LV-GLS were measured, with LV-GLS reported as an absolute value. The primary outcome was cardiovascular (CV) events: CV death, sudden cardiac death-related events, and heart failure hospitalization.

Results: Among 652 patients with HCM (median age 56 years; 74% [481 of 652] male), median LGE% and LV-GLS were 4.2% and 14.3%, respectively. During the median 7.4-year follow-up (Q1-Q3: 3.4-10.3 years), 59 patients (9.0%) experienced CV events. Higher LGE% and lower LV-GLS were associated with increased CV events (per 1% LGE% increase, adjusted HR [aHR]: 1.04 [95% CI: 1.01-1.06; P = 0.005]; per 1% LV-GLS decrease, aHR: 1.08 [95% CI 1.00-1.15; P = 0.038]). When analyzing the 4 groups stratified according to LGE% and LV-GLS, patients with both high LGE% (>4.2%) and low LV-GLS (<14.3%) had the highest incidence of CV events (aHR: 2.88; 95% CI: 1.21-6.85; P = 0.017). Mediation analysis showed a significant indirect effect of LGE% on CV events through LV-GLS. Sudden cardiac death-related events were most frequent in patients with both high LGE and low LV-GLS.

Conclusions: LGE and LV-GLS provide complementary prognostic information in HCM. Patients with both increased LGE and decreased LV-GLS are at particularly high risk, highlighting the value of integrating both biomarkers for risk stratification.