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

BACKGROUND

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

METHODS

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.

RESULTS

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%).

CONCLUSIONS

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.