Risk factors for stroke and thromboembolism in relation to age amongst patients with atrial fibrillation: The Loire Valley Atrial Fibrillation Project.
Chest. 2011 Jun 16;
Authors: Olesen JB, Fauchier L, Lane DA, Taillandier S, Lip GY
Abstract BACKGROUND: According to the latest European guidelines on the management of non-valvular atrial fibrillation (NVAF), all patients aged ?65 years should be treated with oral anticoagulation (if not contraindicated). Therefore, stroke risk factors should be investigated exclusively in NVAF patients aged <65 years. METHODS: Patients diagnosed with NVAF in a four-hospital-institution between 2000-2010 were indentified. Event rates of stroke/thromboembolism were calculated according to age category, i.e. age <65, 65-74, and ?75 years. Independent risk factors of stroke and thromboembolism were investigated in univariate and multivariate Cox regression models including NVAF patients aged <65 years only. The effect of adding vascular disease to the CHADS(2) score was examined by Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) models. RESULTS: Among 6,438 patients with NVAF, 2,002 (31.1%) were aged <65 years. In non-anticoagulated patients with no CHADS(2) risk factors (n=1,035), the stroke/thromboembolic event rate per 100 person-years was 0.23 (95% confidence interval 0.08-0.72), 2.05 (1.07-3.93), and 3.99 (2.63-6.06) in those aged <65, 65-74, and ?75 years, respectively. Heart failure, previous stroke, and vascular disease were significantly associated with increased risk of stroke/thromboembolism in both univariate and multivariate analyses, and vascular disease significantly improved the predictive ability of the CHADS(2) score (NRI 0.40, IDI 0.031). CONCLUSIONS: NVAF patients aged ?65 years have event rates that merit oral anticoagulation. In NVAF patients aged <65 years, the risk of stroke/thromboembolism is independently increased by the presence of heart failure, previous stroke, or vascular disease. As proposed in the new CHA(2)DS(2)-VASc score, stroke risk stratification by the CHADS(2) score can be improved by the addition of age 65-74 years and vascular disease.
PMID: 21680645 [PubMed - as supplied by publisher]