Benefit of Anticoagulation Therapy in Hyperthyroidism-Related Atrial Fibrillation

Pak-Hei Chan, Jojo Hai, Chun-Yip Yeung, Gregory Y.H. Lip, Karen Siu-Ling Lam, Hung-Fat Tse, Chung-Wah Siu
2015 Clinical Cardiology  
Existing data on the risk of ischemic stroke in hyperthyroidism-related atrial fibrillation (AF) and the impact of long-term anticoagulation in these patients, particularly those with self-limiting AF, remain inconclusive. Hypothesis: Risk of stroke in hyperthyroidism-related AF is the same as nonhyperthyroid counterparts. Methods: This was a single-center observational study of 9727 Chinese patients with nonvalvular AF from July 1997 to December 2011. Patients with AF diagnosed concomitantly
more » ... sed concomitantly with hyperthyroidism were identified. Primary and secondary endpoints were defined as hospitalization with ischemic stroke and intracranial hemorrhage in the first 2 years. Patient characteristics, duration of AF, and choice of antithrombotic therapy were recorded. Self-limiting AF was defined as <7 days' duration. Results: Out of 9727 patients, 642 (6.6%) had concomitant hyperthyroidism and AF at diagnosis. For stroke prevention, 136 and 243 patients (21.1% and 37.9%) were prescribed warfarin and aspirin, respectively, whereas the remaining patients (41.0%) received no therapy. Ischemic stroke occurred in 50 patients (7.8%), and no patient developed hemorrhagic stroke. Patients with CHA 2 DS 2 -VASc of 0 did not develop stroke. Warfarin effectively reduced the incidence of stroke compared with aspirin or no therapy in patients with CHA 2 DS 2 -VASc ≥1 and non-self-limiting AF, but not in those with self-limiting AF or CHA 2 DS 2 -VASc of 0. Presence of hyperthyroidism did not confer additional risk of ischemic stroke compared with nonhyperthyroid AF. Conclusions: Patients with hyperthyroidism-related AF are at high risk of stroke (3.9% per year). Warfarin confers stroke prevention in patients with CHA 2 DS 2 -VASc ≥1 and non-self-limiting AF. Overall stroke risk was lower in hyperthyroid non-self-limiting AF patients compared with nonhyperthyroid counterparts. 476
doi:10.1002/clc.22427 pmid:26248681 fatcat:wa5ts3wkjzeebnqgkm2zxof3lm