Severity, Outcomes, and their Secular Changes in 33,870 Ischemic Stroke Patients with Atrial Fibrillation in a Hospital-Based Registry: Japan Stroke Data Bank.

Aim: Severity, functional outcomes, and their secular changes in acute atrial fibrillation (AF)-associated stroke patients were determined.

Methods: Acute ischemic stroke patients with AF in a hospital-based, multicenter, prospective registry from January-2000 through December-2020, were compared with those without AF. The co-primary outcomes were the initial severity assessed by the NIH Stroke Scale (NIHSS) score and favorable outcome assessed by the modified Rankin Scale scores 0-2 at hospital discharge.

Results: Of the 142,351 patients studied, 33,870 had AF. AF patients had higher NIHSS scores (median 9 vs. 3, adjusted coefficient 5.468, 95% CI 5.354-5.582) than non-AF patients. Favorable outcome was less common in AF patients than in non-AF patients in the unadjusted analysis (48.4% vs. 70.4%), but it was more common with adjustment for the NIHSS score and other factors (adjusted OR 1.110, 95% CI 1.061-1.161). In AF patients, the NIHSS score decreased throughout the 21-year period (adjusted coefficient -0.088, 95% CI -0.115 - -0.061 per year), and the reduction was steeper than in non-AF patients (P＜0.001). In AF patients, favorable outcome became more common over the period (adjusted OR 1.018, 95% CI 1.010-1.026), and the increase was steeper than in non-AF patients (P＜0.001); the increase was no longer significant after further adjustment by reperfusion therapy.

Conclusions: Initial stroke severity became milder and functional outcomes improved in AF patients over the 21-year period. These secular changes were steeper than in non-AF patients, suggesting that AF-associated stroke seemed to reap more benefit of recent development of stroke care than stroke without AF.