Apixaban vs Aspirin According to CHA2DS2-VASc Score in Subclinical Atrial Fibrillation

ARTESiA (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation) demonstrated that apixaban, compared with aspirin , significantly reduced stroke and systemic embolism (SE) but increased major bleeding in patients with subclinical atrial fibrillation. To help inform decision making, the authors evaluated the efficacy and safety of apixaban according to baseline CHA 2 DS 2 -VASc score. We performed a subgroup analysis according to baseline CHA 2 DS 2 -VASc score and assessed both the relative and absolute differences in stroke/SE and major bleeding. Baseline CHA 2 DS 2 -VASc scores were 4 in 1,085 (27.0%). For patients with CHA 2 DS 2 -VASc >4, the rate of stroke was 0.98%/year with apixaban and 2.25%/year with aspirin ; compared with aspirin, apixaban prevented 1.28 (95% CI: 0.43-2.12) strokes/SE per 100 patient-years and caused 0.68 (95% CI: −0.23 to 1.57) major bleeds . For CHA 2 DS 2 -VASc 4 and a stroke/SE risk of 2.2% per year. For these patients, the benefits of treatment with apixaban in preventing stroke/SE are greater than the risks. The opposite is true for patients with CHA 2 DS 2 -VASc score <4. A substantial intermediate group (CHA 2 DS 2 -VASc =4) exists in which patient preferences will inform treatment decisions. (Apixaban for the Reduction of Thrombo-Embolism in Patients With Device-Detected Sub-Clinical Atrial Fibrillation ; NCT01938248 )