Vascular disease and stroke risk in atrial fibrillation: a nationwide cohort study
American Journal of Medicine, 08/08/2012
Olesen JB et al. – Vascular disease is an independent predictor of stroke/thromboembolism in atrial fibrillation and improves the predictive ability of the CHADS2 score.Methods
- By using nationwide Danish registers, authors identified all patients discharged with atrial fibrillation and not treated with vitamin K antagonist or heparin between 1997 and 2008.
- The rate of stroke/thromboembolism in patients with atrial fibrillation with and without vascular disease was determined, and the risk associated with vascular disease was estimated in Cox regression analyses.
- The value of adding vascular disease to the CHADS2 score was evaluated by Net Reclassification Improvement and Integrated Discrimination Improvement.
- Authors included 87,202 patients with non–valvular atrial fibrillation; of these, 15,212 (17.4%) had vascular disease, 11,750 (77.2%) had myocardial infarction, 2503 (16.5%) had peripheral artery disease, and 959 (6.3%) had both.
- In patients with a CHADS2 score=0, the rate of stroke/thromboembolism at 1–year follow–up was 2.31 (1.63–3.26) and 1.52 (1.34–1.73) per 100 person–years in patients with and without vascular disease, respectively.
- Vascular disease increased the risk of stroke/thromboembolism in both univariate (hazard ratio [HR] 1.26; confidence interval [CI], 1.18–1.35) and multivariate (HR, 1.12; CI, 1.05–1.21) analyses.
- The risk of stroke/thromboembolism associated with peripheral artery disease alone (HR, 1.93; CI, 1.70–2.19) was greater than the risk with myocardial infarction alone (HR, 1.12; CI, 1.04–1.21), and vascular disease significantly improved the predictive ability of the CHADS2 score (Net Reclassification Improvement 0.032, P<.001).