Importance of Paroxysmal Atrial Fibrillation and Sex Differences in the Prevention of Embolic Stroke in Hypertrophic Cardiomyopathy

Background: Although atrial fibrillation (AF) is a well-known risk factor for embolic stroke in hypertrophic cardiomyopathy (HCM), there is a paucity of information derived from HCM patients who have experienced embolic stroke. Methods and Results: From 141 consecutive HCM patients who had been hospitalized between 2000 and 2018, the clinical characteristics and management of 86 patients with AF were analyzed retrospectively. The incidence of embolic stroke was 36% (n=31 patients). The median (interquartile range) age of embolic stroke was younger in male than female HCM patients (71 [64–80] vs. 83 [77–87] years, respectively; P=0.009). The prevalence of paroxysmal AF (74%) was significantly higher than that of chronic AF (26%) in 31 patients with embolic stroke (P=0.007). The CHADS(2) score in patients with embolic stroke was not particularly useful in predicting the occurrence of embolic stroke. Conclusions: One-third of HCM patients with AF developed embolic stroke, and male HCM patients were younger at the time of the embolic stroke than female HCM patients. The prevalence of paroxysmal AF was significantly higher than that of chronic AF in patients with AF and embolic stroke. Early introduction of anticoagulation therapy is recommended at the first documentation of paroxysmal AF.