High pre-stroke CHADS₂ score predicts unfavorable functional outcome in acute cardioembolic stroke patients prescribed oral anticoagulant therapy: A sub-analysis of the PASTA registry study

Background and purpose: The impact of CHADS(2) score on outcome in patients with stroke taking an oral anticoagulant (OAC) has not yet been fully elucidated. We investigated the association between pre-stroke CHADS(2) score and outcome at discharge in patients with acute cardioembolic (CE) stroke due to atrial fibrillation (AF) who were prescribed OAC.Methods: The data of 548 OAC-treated patients with AF and CE stroke who were registered in the multicenter Prospective Analysis of Stroke patients Taking oral Anticoagulants (PASTA) study were analyzed. High CHADS(2) score was defined as a pre-stroke CHADS(2) score >= 2. Unfavorable outcome was defined as a modified Rankin scale (mRS) of 3-6. The impacts of pre-stroke CHADS(2) score on outcome at discharge were evaluated using multiple logistic regression analysis.Result: A high CHADS(2) score was found in 472/548 patients and unfavorable outcome was found in 330/548 patients. In patients with unfavorable outcome, age, male sex, pre-stroke CHADS2 score, initial National Institute Health Stroke Scale (NIHSS) score, and glucose level on admission were significantly higher, whereas creatinine clearance and body weight were significantly lower, than those with favorable outcome (each p < 0.001). Multivariate logistic regression analysis indicated that high CHADS(2) score (OR 2.18, 95 %CI 1.08-4.42, p = 0.031), pre-stroke mRS (OR 2.21, 95 %CI 1.69-2.67, p < 0.001), and initial NIHSS score (OR 1.19, 95 %CI 1.17-1.24, p < 0.001) were independently associated with unfavorable outcome.Conclusion: Pre-stroke CHADS(2) score was associated with poor outcome in patients with cardioembolic stroke due to AF, even in those taking OAC.