Prediction of Thromboembolism in Patients With Hypertrophic Cardiomyopathy

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 CHADS₂ 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.

Thromboembolism in Patients with Hypertrophic Cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disease, which has a marked heterogeneity in clinical expression, natural history, and prognosis. HCM is associated with a high prevalence of thromboembolic events (stroke and systemic embolic events), even if taking no account of atrial fibrillation (AF), leading to unexpected disability and death in patients of all ages. Several risk factors of thromboembolism such as AF, greater age, left atrial diameter, heart failure and others have been confirmed in patients with HCM. Conventional thromboembolic predictive models were estimated by several trials in HCM population but it turned out to be unsatisfactory. Based on those previous explorations, researchers tried to modify or develop novel models suitable for HCM population in thromboembolism prediction. In consideration of catastrophic advent events of thromboembolism, current guidelines have recommended life-long anticoagulant therapy after a single short AF. Therefore, early identification of risk factors for thromboembolism, accurate risk stratification, timely preventive measures and aggressive management may help to avoid serious adverse thromboembolic events in HCM population.