Impact of Pre-Stroke Antiplatelet Use on 3-Month Outcome After Ischemic Stroke

Background: Pre-stroke anti-platelet (PAP) therapy can potentially influence the severity and outcome after ischemic stroke. Methods: We analyzed data from the prospective multicenter IndouUS collaborative stroke project for the impact of PAP therapy. Outcome measures included the admission National Institute of Health Stroke Scale (NIHSS) score, 3-month modified Rankin scale (mRS) score, and rates of in-hospital mortality and post-ischemic intracerebral hemorrhage. Results: Among 2048 of 2066 patients (M:F = 2:1) with known pre-stroke medication status, 336 (16.3%) were on PAP therapy. As compared to the non-PAP group, the PAP group had significantly higher mean age (62.2 vs 57.4 years, P < 0.001) and significantly more men, vascular risk factors, cerebral microbleeds (12.8% vs 6.2%, P = 0.001) and intravenous thrombolysis treatment (17% vs. 10.6%, P = 0.001). Cardioembolic strokes were significantly more in the PAP group (P < 0.001), but not large artery atherosclerosis. No significant differences were observed in the median NIHSS score (9 vs. 10, P = 0.274), 3-month mRS (score 0-2,51.4% vs. 49.0%, P = 0.428), in-hospital mortality (8.6% vs. 7.8%, P = 0.592), or symptomatic post ischemic intracerebral haemorrhage (12.2% vs. 10.6%, P = 0.382). The PAP group had more stroke recurrence (6.6% vs. 2.9%, P = 0.002) which was not significant (P = 0.065) after multivariate regression analysis adjusting for age, sex and vascular risk factors. PAP therapy was not an independent predictor of initial stroke severity or stroke outcome. Conclusion: PAP therapy has no significant effect on initial stroke severity, rates of post-ischemic hemorrhage with or without thrombolysis, in-hospital mortality, stroke recurrence, and 3-month outcome after ischemic stroke.