Prestroke antiplatelet agents in first-ever ischemic stroke: clinical effects.

OBJECTIVE: To investigate whether prestroke antiplatelet agent (PA) use was associated with initial stroke severity.

METHODS: This was a retrospective, case-control study based on data from a prospectively collected hospital-based stroke registry (Korea University Stroke Registry). A total of 3,025 patients who were admitted with a diagnosis of first-ever ischemic stroke within 5 days of symptom onset were included. Stroke severity was measured with the NIH Stroke Scale (NIHSS). NIHSS score ≤4 at admission was categorized as mild stroke. Patients from the PA group were matched with those from the non-PA group using estimated propensity scores at a 1:1 ratio. Stepwise multivariable logistic regression analyses were performed on patients in the matched datasets with initial mild stroke.

RESULTS: Patients' mean age was 66.3 ± 13.0 years, and 1,850 were men (61.5%). A total of 748 patients had been taking antiplatelet agents prior to stroke onset; 644 patients (86.1%) were taking a single antiplatelet agent. Among these agents, aspirin (83.7%) was the most common. A total of 102 patients (13.6%) were taking 2 antiplatelet agents. Multivariable analysis after propensity score matching demonstrated that PA use was associated with initial mild stroke (odds ratio 1.344; 95% confidence interval 1.014-1.782).

CONCLUSIONS: PA use was associated with decreased first-ever stroke severity, suggesting that it has a beneficial effect.

CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that prestroke use of antiplatelet agents reduces stroke severity in patients with first-ever acute ischemic stroke.