Abstract WMP71: Changes In Severity And Outcomes Of Ischemic Stroke Associated With Atrial Fibrillation In A Long-lasting Nationwide Hospital-based Registry: Japan Stroke Data Bank

Background: To determine secular changes in severity and functional outcomes of acute atrial fibrillation (AF)-associated stroke patients using a large population. Methods: Ischemic stroke patients with known AF or AF diagnosed after stroke onset, who were registered within 7 days after symptom onset into a hospital-based prospective registry, Japan Stroke Data Bank, from Jan 2000 to Dec 2020 were compared with those without AF. The co-primary outcomes were the initial neurological severity assessed by NIHSS and favorable outcome assessed by mRS of 0 to 2 at hospital discharge. Secondary outcomes included unfavorable outcome assessed by mRS of 5 to 6 and in-hospital death. Results: Of 142,351 patients studied, 33,870 had AF (women 45.1%, median age 79 years, non-valvular 94.3%). Patients with AF had higher initial NIHSS score (median 9 vs. 3, adjusted coefficient 5.383, 95% CI 5.245 - 5.520) as compared to patients without AF (women 38.2%, median age 79 years). Anticoagulation prior to the index stroke showed a significant interaction with the frequency of the NIHSS score ≥10 in patients with AF relative to those without AF (aOR: 2.047 for anticoagulated patients vs. 4.189 for the others). The NIHSS score decreased over the 21-year period in AF patients (adjusted coefficient -0.104, 95% CI -0.133 - -0.074 per year). Favorable outcome was less common in patients with AF than those without AF in unadjusted analysis (48.4% vs. 70.4%) but was more common after multivariable adjustment including the initial NIHSS score (aOR 1.096, 95% CI 1.040 - 1.156). Unfavorable outcome (aOR 1.108) and in-hospital death (1.506) were also more common in AF patients. The proportion of favorable outcome showed an increase over time (aOR 1.018, 95% CI 1.009 - 1.026 per year) in AF patients but the increase was no longer significant after further adjustment by receiving reperfusion therapy (1.007, 0.998 - 1.016). The proportion of unfavorable outcome and that of in-hospital death showed a yearly decrease over time. Conclusions: AF patients showed favorable clinical outcome after ischemic stroke relative to patients without AF by adjustment using the NIHSS score and others. Initial stroke severity became milder and functional outcomes tended to improve in AF patients during the past 21 years.