Prevalence of Stroke/Transient Ischemic Attack Among Patients with Acute Coronary Syndromes in a Real-World Setting

BACKGROUND: Atherothrombosis is a systemic disease that may manifest as acute ischemic events in multiple vascular beds. Patients who have experienced an atherothrombosis-related ischemic event in 1 vascular bed are at risk for developing ischemic events in other vascular beds. Antiplatelet therapy demands an understanding of the balance between arterial thrombosis benefit and adverse event risk. Clinical trials indicate that dual antiplatelet therapy with aspirin and the newer thienopyridines increases the risk of bleeding in patients with acute coronary syndromes (ACS) with prior cerebrovascular events. Informed clinical decision making requires a better understanding of the real-world prevalence of cerebrovascular events. OBJECTIVE AND PURPOSE: To estimate the prevalence of stroke and/or transient ischemic attack (TIA) among patients with ACS within US health plan populations. METHODS: A retrospective, observational cohort study was conducted of patients with ACS in 5 health care claims databases. The index event was defined as the first documented inpatient health care claim for myocardial infarction or unstable angina. Patients with ≥12 months of pre-index medical care encounter information were included. Stroke/TIA was identified by the first health care claim for these conditions any time prior to or within 90 days following the index ACS event. RESULTS: Across all databases, between 3.8% and 15.7% of patients with ACS had prior stroke/TIA and between 3.4% and 11.7% of patients with ACS with no history of cerebrovascular events had documented stroke/TIA following the index ACS hospitalization. CONCLUSION: Despite important differences between the various database populations, there is a high prevalence of documented stroke/TIA in patients with ACS both prior to and following the ACS event. These real-world findings, set within the context of the increased bleeding risk observed with the newer thienopyridines, are important considerations when selecting antiplatelet therapy for patients with ACS.