Pre-Stroke Antiplatelet use and Clinical Outcome in Patients with Ischemic Stroke in a Tertiary Care Hospital

Background: Stroke remains a significant cause of death and disability globally. The use of pre-stroke antiplatelet (PAP) therapy has been shown to influence stroke severity and outcomes, though findings from various studies have been mixed. This study aims to investigate the effect of pre-stroke antiplatelet use on stroke severity, early neurological deterioration (END), and long-term functional outcomes in acute ischemic stroke (IS) patients, focusing on differences across stroke subtypes. Methods: A prospective observational study was conducted from September 2022 to August 2024, involving 600 patients with their first-ever ischemic stroke admitted within 24 hours of symptom onset. Patients were classified based on prior use of antiplatelet agents, and stroke subtypes were identified using the TOAST classification large artery atherosclerosis [AT], small artery disease [SAD], and cardio-embolic [CE] stroke). Stroke severity was measured using the NIH Stroke Scale (NIHSS) at admission, and functional recovery was evaluated using the modified Rankin Scale (mRS) at three months. Clinical outcomes including END, recurrent ischemic stroke (RIS), hemorrhagic transformation (HT), and mortality were also assessed. Results: Out of the 600 participants, 137 (22.83%) had taken antiplatelet agents prior to their stroke. PAP users had significantly lower NIHSS scores upon admission, particularly in patients with AT stroke (P < 0.001). Antiplatelet use was linked to a reduced risk of END (HR: 0.78; 95% CI: 0.56–0.91; P = 0.03) and better functional outcomes at three months (mRS ≤2; 48.9% vs. 21.6%, P < 0.001), despite an elevated risk of asymptomatic HT (HR: 1.35; 95% CI: 1.08–3.07; P = 0.001). The positive impact of PAP use on functional outcomes was observed across all stroke subtypes. Conclusion: Pre-stroke antiplatelet therapy is associated with reduced stroke severity, particularly in large artery atherosclerosis, and leads to better functional outcomes at three months, irrespective of stroke subtype. Despite an increased risk of asymptomatic hemorrhagic transformation, the overall clinical benefit of antiplatelet use in acute ischemic stroke is evident.