(HealthDay)—For atrial fibrillation (AF) ablation patients undergoing their index ablation, long-term aspirin therapy is associated with increased rates of bleeding and may not lower risk of stroke, according to a study published online Aug. 28 in the Journal of Cardiovascular Electrophysiology.

Victoria Jacobs, Ph.D., from the Intermountain Medical Center Heart Institute in Murray, Utah, and colleagues included 4,124 AF ablation patients undergoing index ablation in a retrospective observational study. The authors compared one- and three-year outcomes for patients receiving aspirin or warfarin as long-term therapies versus no therapy.

The researchers found that patients with higher CHADS2VASc scores were more likely to be female and have hypertension, diabetes mellitus, heart failure, or vascular disease (P < 0.0001 for all). Overall, 5.9, 18.6, and 75.5 percent of patients were on warfarin, aspirin, and no therapy at three years, respectively; with advancing CHA2DS2VASc score, the occurrences of cerebrovascular accident/transient ischemic attack (CVA/TIA) were 1.4, 3.0, and 3.9 percent, respectively (P < 0.0001); was 0.8, 1.9, and 1.1 percent, respectively (P = 0.06); and genitourinary bleeding was 1.7, 2.8, and 2.1 percent, respectively (P = 0.008). Compared with no therapy or , aspirin therapy was associated with increased risk for both CVA/TIA and across all CHA2DS2VASc scores.

"After , low risk patients do not benefit from long-term aspirin therapy, but are at risk for higher rates of bleeding when compared to no therapy or warfarin," the authors write.