Assessing Potential Benefit of Stroke Prophylaxis Therapy in Atrial Fibrillation and Atrial Flutter Using a Novel...

The competing risk of nonstroke mortality may limit the potential benefit of stroke prophylaxis therapy in patients with atrial fibrillation or atrial flutter AF.

Using a Medicare 20% sample, we identified a cohort of beneficiaries diagnosed with atrial fibrillation or atrial flutter from 2006 to 2019 using International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) codes. Fine and Gray regression analysis determined the hazard of stroke with a competing risk of nonstroke mortality, and Cox proportional hazard analysis determined risk of nonstroke mortality. A scoring tool stratified patients into low or high potential benefit for thromboembolic prophylaxis.

Among a total of 1 883 759 Medicare beneficiaries, 330 136 patients were included with median age of 79.7 years. 54% of patients had prior bleeding episodes. The median CHA₂DS₂-VASc score was 5. Of these patients, 211 791 (64%) died and 77 717 (24%) experienced an embolic stroke over median follow-up of 7.3 years. In the high potential benefit group (26.1%), the risk of stroke was much higher than the risk of nonstroke mortality at 1 year (12.2% versus 7.1%); 3 years (22.7% versus 16.9%); 5 years (31.9% versus 26.1%). In the low potential benefit group (73.9%), the risk of stroke was much lower than the risk of nonstroke mortality at 1 year (11.5% versus 39.2%); 3 years (23.2 versus 57.2%); and 5 years (34.3% versus 69.4%).

We propose a scoring tool to identify the potential benefit of thromboembolic prophylaxis therapy in older patients diagnosed with atrial fibrillation or atrial flutter. This tool can be used in shared decision-making settings. Further studies to improve and validate this scoring tool are warranted.