Antiplatelet treatment patterns and outcomes of secondary stroke prevention in the United States.

Objective: Patients who have an ischemic stroke (IS) or transient ischemic attack (TIA) are at risk of having a secondary stroke. Single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT) may be recommended for secondary stroke prevention (SSP), depending on severity and etiology. This study evaluated outpatient antiplatelet treatment patterns for SSP and outcomes after first hospitalization for IS/TIA among adults without atrial fibrillation in the United States. Materials and methods: This retrospective observational study utilized data from an adjudicated administrative health claims database. Eligible patients had an imputed National Institutes of Health Stroke Scale index event score ≤7. Over-the-counter medication use (eg, aspirin) was not captured. Results: Of 154,273 patients, 41,622 (27%) were prescribed antiplatelet therapy within 90 days of the event; 93.8% received SAPT, 6.1% received DAPT. The first line of antiplatelet therapy after discharge was started a mean of 17.0 days after the event; mean treatment duration was 61.9 days. The incidence rate for secondary IS was 5.53, 2.03, and 1.17 per person-year 90-days, 1-year, and 3-years following treatment initiation, respectively. Among patients matched for demographic and clinical characteristics, the risk of secondary IS was increased with DAPT versus SAPT (hazard ratio [95% CI]: 1.27 [1.20-1.34]; p < 0.0001). Conclusions: Many patients were not prescribed or discontinued antiplatelet therapy within 90 days of hospitalization for IS/TIA and, in most cases, prescriptions were not compliant with SSP consensus guidelines. Patients remained at risk for IS, which was highest within 90 days. More effective strategies for SSP are needed to improve outcomes in this patient population.