Predictors of ischemic stroke severity and long-term functional outcomes in patients with and without atrial fibrillation

BACKGROUND: Ischemic stroke patients with atrial fibrillation (AF) may have different mechanisms and prognostic determinants than those without AF. We investigated predictors of initial stroke severity and 3-month functional outcome in first-ever ischemic stroke, stratified by AF status. METHODS: Consecutive patients with first-ever acute ischemic stroke admitted within 7 days of onset to Taitung MacKay Memorial Hospital from December 31, 2014, to December 31, 2020, were analyzed. Admission National Institutes of Health Stroke Scale (NIHSS) and 3-month modified Rankin Scale (mRS) scores were evaluated using multivariable general linear models stratified by AF status. The 3-month mRS models assessed whether associations persisted after adjustment for admission NIHSS. RESULTS: Overall, 1256 patients were included (non-AF, n = 955; AF, n = 301). Patients with AF were older and had higher admission NIHSS and 3-month mRS scores than those without AF. In the non-AF group, age ≥75 years, betel nut chewing, and sedentary lifestyle were associated with higher admission NIHSS, whereas dyslipidemia was associated with lower admission NIHSS. In the AF group, sedentary lifestyle was associated with higher admission NIHSS, whereas obesity and pre-stroke anticoagulant therapy were associated with lower admission NIHSS. After adjustment for admission NIHSS, type 2 diabetes was independently associated with higher 3-month mRS in both groups. Age ≥75 years and sedentary lifestyle remained associated with higher 3-month mRS only in the non-AF group. CONCLUSION: Predictors of initial stroke severity and 3-month functional outcome differ by AF status. Stratified prognostic assessment may guide individualized secondary prevention and post-stroke management.