Abstract 4007: Association between Post-discharge Oral Antiplatelet Use and Clinical Outcomes among US Patients Hospitalized for Transient Ischemic Attack or Stroke
Background: More than 800,000 Americans have a stroke or transient ischemic attack (TIA) each year. Antiplatelets are recommended to reduce the risk of recurrence and other clinical events. Conflicting data exist regarding the relative efficacy of two common oral antiplatelets (OAPs): aspirin plus extended-release dipyridamole (ASA-ERDP) and clopidogrel (CLO).
Objective: To examine clinical outcomes using real-world data among patients hospitalized for TIA or stroke and initially prescribed ASA-ERDP or CLO post-discharge.
Methods: This retrospective claims study from a US commercial and Medicare health plan analyzed adults who had at least one hospitalization for TIA or stroke between 01/2007 and 07/2009 and at least one pharmacy claim for an OAP within 30 days of discharge. Patients were observed for one year before and after the first hospitalization or until death. Post-discharge outcomes included vascular events, clinically relevant bleeds, and all-cause death. The composite and individual outcome measures were modeled using logistic multivariate (MV) regression, adjusting for baseline demographics, comorbidities, costs, and initial OAP use.
Results: In total, 6,377 subjects (2,085 ASA-ERDP; 4,292 CLO) met the inclusion criteria. ASA-ERDP had a lower unadjusted proportion with the composite endpoint than CLO (19.1% vs. 22.0%, respectively; p=0.01). Significant unadjusted outcomes in the composite were: CHF (8.1% vs. 10.8%; p<0.001), MI (2.4% vs. 4.0%; p=0.001), GI bleeds (3.5% vs. 4.7%; p=0.03), and other hemorrhagic events (2.0% vs. 3.0%; p=0.02). Unadjusted stroke/TIA readmission was not significant (9.1% vs. 9.0%; p=0.95). MV modeling indicated age, comorbidities, index stroke/TIA event, and baseline costs as significant risk factors associated with the composite endpoint. Compared to CLO, the initial use of ASA-ERDP post-discharge was associated with 15% lower risk in the composite endpoint (OR = 0.85; p=0.03), but GI bleeding was the only significant individual component (OR=0.56; p=0.003).
Conclusion: This study suggests that in the year following discharge for TIA or stroke, patients who received ASA-ERDP had a lower likelihood of the composite endpoint, due partly to GI bleeding, than patients who received CLO.
- © 2012 by American Heart Association, Inc.