There are various schemas designed to stratify the risk of thromboembolism (TE) in patients with atrial fibrillation (AF), of which the CHADS2 (congestive heart failure, hypertension, age ≥ 75 y, diabetes, stroke [doubled]) score is the most widely studied. We evaluated whether the CHADS2 score was adequate for TE risk stratification while assessing cardiac risk in patients with AF revascularized with coronary artery stents.
We reviewed 604 consecutive patients with AF treated with at least one stent between 2001 and 2008 in relation to TE risk using CHADS2 score. We stratified our patients with a CHADS2 score ≤ 1 as low-moderate thromboembolic risk (group 1: n = 193, 32%) and > 1 as high risk (and, hence, requiring anticoagulation; group 2: n = 411, 68%). We determined the benefits and/or risks of oral anticoagulation (OAC) therapy in both cohorts.
Completed follow-up was achieved in 90.4% (mean 642.2 days). Group 1 event-free survival was better than group 2 (major adverse cardiovascular events [MACEs], log-rank test P = .03; and death, log-rank test P = .03). In group 1, event-free survival was better on OAC vs non-OAC use (death 5% vs 15%, P = .04; MACE 10% vs 26%, P < .01) with a trend for more major hemorrhages (12% vs 4%, P = .08). Stroke rate was 4.1% per 100 patient-years in patients without OAC therapy and 1.38% in patients on OAC therapy. Group 2 had a lower incidence of death (20% vs 34%, P < .01) and MACE (26% vs 43%, P < .01) among those on OAC therapy on discharge, with a higher incidence of major hemorrhages (18% vs 8%, P < .01).
In a population of patients with AF revascularized with stents, even those with CHADS2 ≤ 1 should be regarded as being at high risk. OAC should be considered as thromboprophylaxis in patients with AF revascularized with coronary stents.