Risk of ischemic stroke in patients with hypertrophic cardiomyopathy in the absence of atrial fibrillation - a nationwide cohort study

Ischemic stroke (IS) is a catastrophic complication of hypertrophic cardiomyopathy (HCM) with aging. We investigated the incidence of IS in HCM patients without atrial fibrillation (AF) and compared the relative risk of IS with matched general population with AF. This study identified 17,371 HCM patients without AF and utilized propensity-score-matching to identify one-to-one matched control of general population with AF receiving oral anti-coagulants (OACs). During a median follow-up of 7.3 years, 847 (4.9%) subjects experienced IS with the incidence of 0.589/100 person-years. The corresponding matched controls experienced 788 (4.5%) events with the incidence of 0.494/100 person-years. Compared with control, HCM patients had similar risk of IS (Hazard ratios [HRs] 0.965, 95% confidence interval [CI] 0.854-1.091). HCM patients with age above 65 years had a significantly increased risk of IS (age 65-74 years, HR 1.278, 95% CI 1.070-1.335; age >= 75 years, HR 1.757, 95% CI 1.435-2.152). Stratified by CHA(2)DS(2)-VASc score, HCM subjects with score 0, 1 and 2 had significantly increased risk of IS than control while those with score >= 2 had similar risk as control. Compared with general population with AF, HCM patients without AF had similar risk of IS, suggesting OACs might be necessary in HCM patient without AF.