Oral Anticoagulation and the Risk of Stroke or Death in Patients With Atrial Fibrillation and One Additional Stroke Risk Factor

Abstract

It remains uncertain whether patients with atrial fibrillation (AF) and a single additional stroke risk factor (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke or thromboembolism, vascular disease, age 65-74 years, and sex category [CHA2DS2-VASc] score = 1 in men, 2 in women) should be treated with oral anticoagulation (OAC). We investigated the risk of ischemic stroke, systemic embolism, and death in a community-based cohort of unselected patients with AF with zero to one stroke risk factor based on the CHA2DS2-VASc score. Among 8,962 patients with AF seen between 2000 and 2010, 2,177 (24%) had zero or one additional stroke risk factor, of which 53% were prescribed OAC. Over a follow-up of 979 ± 1,158 days, 151 (7%) had a major adverse event (stroke/systemic thromboembolism/death). Prescription of OAC was not associated with a better prognosis for stroke/systemic thromboembolism/death for patients in the "low-risk" category (ie, CHA2DS2-VASc score = 0 for men or 1 for women; adjusted hazard ratio [HR], 0.68; 95% CI, 0.35-1.31; P = .25). OAC use was independently associated with a better prognosis in patients with AF with a single additional stroke risk factor (ie, CHA2DS2-VASc score = 1 in men, 2 in women; adjusted HR, 0.59; 95% CI, 0.40-0.86; P = .007). Among patients with AF with a single additional stroke risk factor (CHA2DS2-VASc score = 1 in men, 2 in women), OAC use was associated with an improved prognosis for stroke/systemic thromboembolism/death.