Survival after stroke — The impact of CHADS2 score and atrial fibrillation

ObjectiveThis study examined all-cause mortality in stroke patients with and without documented atrial fibrillation (AF), and the impact of CHADS2 score.DesignA cohort of 105,074 patients, 31,821 (30.3%) with and 73,253 (69.7%) without documented AF, was studied. These patients were registered in the Swedish Stroke Registry during the years 2001–2005. Mortality data were retrieved from the Swedish Cause of Death Register. CHADS2 score prior to stroke were assessed using the Swedish National Discharge Register.ResultsThe age and sex adjusted relative risk (RR) of death was 1.46 (1.43–1.49) for AF vs non-AF patients. High age (≥ 75 years) tripled the risk of death and was the single most important predictor, followed by congestive heart failure, previous stroke and diabetes. Less than half of the AF patients with a CHADS2 score of 1–6 survived more than 5 years, whereas AF patients with a CHADS2 score of 0 had a 73% chance of survival. In patients with AF, the relative risk of death was 6.05 (CI: 2.26–6.95); in subjects with the highest vs the lowest CHADS2 score; the corresponding RR for non-AF patients was 7.93 (CI: 7.01–8.97).ConclusionsThe CHADS2 score seems to have an impact on all-cause mortality after stroke. The CHADS2 score can give valuable insight for other outcome variables apart from having had an ischemic stroke and can be applied to patients with different risk factor profiles, e.g. with a previous known cardiovascular disease but without known AF.