Background and purpose: Stroke and systemic embolic events are known to occur as complications of hypertrophic cardiomyopathy (HCM), and these complications are more common in patients with accompanying atrial fibrillation (AF). The diagnosis of AF is sometimes difficult, however, and it is possible that subclinical asymptomatic paroxysmal episodes or a first episode of AF in patients without previously documented AF may lead to embolic events. We investigated the prevalence of embolic events in patients with HCM and evaluated risk factors for these events in patients without documented AF.
Methods: This study enrolled 593 patients with clinically diagnosed HCM (age at diagnosis, 51.0±15.6 years) from 1980 to 2010.
Results: During a mean follow-up of 10.7±7.5 years, 68 (11.5%) experienced stroke and embolic events. AF had been documented before the event in 29 (42.6%) of them. AF was documented for the first time at the time of the event in 5 (7.4%) and after the event in 10 (14.7%). Among the 431 patients without previously documented AF (39 with events and 392 without events), older age at diagnosis and left atrial dimension ≥48 mm were identified as the independent determinants of the embolic event after adjusting for sex and classic prognostic markers related to HCM.
Conclusions: The incidence of stroke and embolic events was about 1.0% per year in the HCM cohort. AF had not been previously documented before the event in more than half of patients with events. Older age and enlarged left atrial dimension are possible risk factors for embolic events in patients with HCM without documented AF.
Keywords: atrial fibrillation; cardiomyopathies; heart atria; risk factors; stroke.
© 2016 American Heart Association, Inc.