Abstract 12835: Atrial Fibrillation is a Strong Predictor of Stroke in Young Taiwanese Adults
Background: Atrial fibrillation (AF) is an independent risk factor for stroke. However, little is known about the magnitude of AF-associated stroke risk across different categorical age strata compared with their age-matched counterparts without AF. We investigated the incidence of first stroke and stroke subtypes among individuals with and without AF based on the insurance reimbursement claims in Taiwan.
Methods: Using universal insurance claim data in a sample population of 982,232 patients, we identified 1,297 patients with newly diagnosed AF from 2002 to 2004 among the insured ≥30 years of age as the AF group and randomly selected 10,376 age-matched persons without AF as the non-AF group. Both groups were followed up until 2007 to estimate stroke incidences and risks.
Results: Compared with the non-AF group, the stroke incidence rate was 2.6-fold higher in the AF group (50.5 vs. 19.4 per 1000 person-years) with greater trend to be ischemic stroke or transient ischemic attack (90.3% vs. 85.4%, p = 0.04). The overall incidence of stroke among AF patients ≥65 years was much higher than among those aged 30-49 years (63.1 vs. 25.4 per 1000 person-years). However, the age-specific AF to non-AF incidence of stroke showed a decrement trend with age with adjusted hazard ratio (HR) of 5.4, 2.5 and 2.0 for patients aged 30−49, 50−64 and ≥65 years. The risk of stroke increased further for AF patients with co-morbidities of hypertension, hyperlipidemia, diabetes, ischemic heart disease, and heart failure, with the highest for those with diabetes (HR = 4.10, 95% confidence interval [CI] 3.18−5.30). Furthermore, compared with AF patients receiving no therapy, the HRs reduced to 0.57 (95% CI 0.43−0.76) and 0.41 (95% CI 0.27−0.61) respectively for those underwent antiplatelet or anticoagulation treatment.
Conclusions: This study shows that AF is an independent risk factor for stroke in the Taiwan population and the weight of AF as a stroke predictor is even stronger in younger patients. Ischemic stroke remains the predominant type of first stroke in AF patients, attesting the theory of cardioembolism as the principal mechanism of AF-associated stroke.
- © 2011 by American Heart Association, Inc.