Aims: Atrial fibrillation (AF) is associated with a high incidence of strokes/thromboembolism. The CHADS2 score assigns points for several clinical variables to identify stroke risk. The CHA2DS2-VASC score uses the same variables but also incorporates age 65 to 74, female gender, and vascular disease in an effort to provide a more refined risk of stroke/thromboembolism. We aimed to examine oral anticoagulation (OAC) recommendations for a cohort of patients undergoing AF ablation depending upon whether thrombo-embolic risk was determined by the CHADS2 or CHA2DS2-VASC score.
Methods and results: For 1411 patients we compared OAC recommendations for each of these risk stratification schemes to one of the three OAC strategies: (i) NO-OAC, (ii) CONSIDER-OAC, and (iii) DEFINITE-OAC. Compared with the CHADS2 score, the CHA2DS2-VASC score reduced NO-OAC from 40.3 to 21.8% and CONSIDER-OAC from 36.6 to 27.9% while increasing DEFINITE-OAC from 23.0 to 50.2% of patients. Age 65 to 74 and female gender accounted for 95.2% and vascular disease for only 4.8% of recommendations for more aggressive OAC using CHA2DS2-VASC. Most vascular disease occurred in patients with higher CHADS2 scores already recommended for DEFINITE-OAC (P < 0.0001). Reclassifying 30 females of age <65 with a CHA2DS2-VASC score of 1 to the NO-OAC group had minimal effect on the overall recommendations.
Conclusion: Compared with the CHADS2 score, in our AF ablation population, the CHA2DS2-VASC score markedly increases the number of AF patients for whom OAC is recommended. It will be important to determine by randomized trials if this major paradigm shift to greater use of OAC using the CHA2DS2-VASC scoring improves patient outcomes.
Keywords: Anticoagulation; Atrial fibrillation; CHA2DS2-VASC score; CHADS2 score.