Sudden cardiac death (SCD) is a major clinical concern in HCM, demanding improved tools for early risk assessment. A large study in JACC: Cardiovascular Imaging assessed the incremental value of cardiac magnetic resonance (CMR)–derived lLV-GLS in 2,009 patients with HCM.

Over a median follow-up of 88 months, 85 patients (4.2%) experienced SCD or aborted SCD. Lower LV-GLS values were strongly associated with higher SCD risk (9.0% ± 3.6% vs 11.1% ± 3.6%; P < 0.001). LV-GLS remained an independent predictor after adjustment for ESC and ACC/AHA risk factors, increasing 5-year AUCs from 0.72 to 0.77 and from 0.71 to 0.76, respectively. Mediation analysis showed LV-GLS partially accounted for the impact of wall thickness and fibrosis on SCD.

These findings establish LV-GLS as a powerful imaging biomarker that complements current guideline-based models and may improve individualized SCD prevention in HCM.