Sarcoidosis as a Risk Factor for Atrial Fibrillation

Objective: To test the hypothesis that sarcoidosis would be associated with the risk of atrial fibrillation (AF). Background: Most studies investigating cardiac manifestations of sarcoidosis have described the risks of heart failure, conduction system disease, and ventricular arrhythmias. The relationship between AF and sarcoidosis has been scarcely investigated. Methods: We analyzed a population-based cohort study of California residents aged ≥ 21 years in the Office of Statewide Health Planning and Development ambulatory surgery, emergency, or inpatient databases from 2005-2015 investigating risk and predictors of incident AF diagnoses in those with and without sarcoidosis. Those with prevalent AF were excluded. Linkage to the social security death index was utilized to ascertain mortality. Results: Among 21,969,699 California residents, 19,225 (0.09%) patients with sarcoidosis were identified. AF developed in 2,283 (11.6%) of those with sarcoidosis. Sarcoidosis was the strongest predictor of incident AF (HR 10.5, 95% CI 9.9-11.1) identified among all risk factors, including conventional AF predictors. The presence of evidence of cardiac involvement, namely heart failure and ventricular tachycardia, best predicted incident AF among those with sarcoidosis, while traditional risk factors better predicted incident AF in those without sarcoidosis. Approximately 44% (95 CI 31%-57%) of the increased mortality associated with sarcoidosis was statistically explained by the presence of AF. Conclusions: Sarcoidosis is a more potent predictor of incident AF than other well-established risk factors, underscoring the need for surveillance for AF among this population. These data suggest that AF in the absence of an identifiable cause should arouse suspicion for the disease.