In-hospital prognosis of first-ever noncardiogenic ischemic stroke in patients with and without indication for prestroke antiplatelet therapy: Chinese Stroke Center Alliance

BACKGROUND: It is unknown about the influence of prestroke antiplatelet use on early outcomes in patients with and without the indication. We aimed to evaluate the in-hospital prognosis of first-ever noncardiogenic ischemic stroke patients with and without indications of antiplatelet use for primary prevention. METHODS: This was a retrospective, observational study based on a prospective hospital-based registry (Chinese Stroke Center Alliance). Using the data with 436,660 first-ever noncardiogenic acute ischemic strokes recorded from Aug 1, 2015, to July 31, 2019, from 1,453 hospitals in China, we examined the associations between the indication for prestroke antiplatelet use and in-hospital clinical outcomes. RESULTS: Among 436,660 first-ever noncardiogenic ischemic stroke patients, 42,409 patients (9.7%) had a documented previous vascular indication and 394,251 (90.3%) did not. Compared to those without, patients with the indication were associated with increased prevalence of in-hospital morbid conditions, including stroke severity (OR 2.71; 95% CI: 2.62-2.81; P<0.0001), length of stay >14 days (OR 1.16; 95% CI: 1.13-1.19; P<0.0001), mortality (OR 2.20; 95% CI: 1.96-2.46, P<0.0001), and recurrence of ischemic stroke and transient ischemic attack (TIA) (OR 1.5; 95% CI: 1.43-1.59, P<0.0001). Among patients without indication, prestroke antiplatelet use was associated with lower mortality (OR 0.73, 95% CI: 0.56-0.96; P=0.0221); while among patients with indication, those receiving prestroke antiplatelet had lower odds ratios in stroke severity (P<0.0001) and disability (P=0.0003) than those who not. CONCLUSIONS: Patients with indications of prestroke antiplatelet use were more likely to have unfavorable outcomes than those without. Prestroke antiplatelet might be associated with lower mortality, less disability, and less stroke severity in certain population groups. Future studies to improve risk prediction rules are needed to guide effective primary prevention for ischemic stroke.