Tailoring Antiplatelet Therapy Intensity to Ischemic and Bleeding Risk

Abstract

Background: Balancing ischemic and bleeding risk is an evolving framework.

Methods and results: Our objectives were to simulate changes in risks for adverse events and event-driven costs with use of ticagrelor or prasugrel versus clopidogrel according to varying levels of ischemic and bleeding risk. Using the validated PARIS risk functions, we estimated 1-year ischemic (myocardial infarction or stent thrombosis) and bleeding (Bleeding Academic Research Consortium types 3 or 5) event rates among PARIS study participants who underwent percutaneous coronary intervention with drug-eluting stent implantation for an acute coronary syndrome and were discharged with aspirin and clopidogrel (n=1497). Simulated changes in adverse events with ticagrelor or prasugrel were calculated by applying treatment effects from randomized trials for a 1-year time horizon. Event costs were estimated using National Inpatient Sample data. Net costs were calculated between antiplatelet therapy groups according to level of ischemic and bleeding risk. After weighting events for quality-of-life impact, we calculated event rates and costs for risk-tailored treatment versus clopidogrel under multiple drug pricing assumptions. One-year rates (per 1000 person-years) for ischemic events were 12.6, 24.1, and 66.1, respectively, among those at low (n=630), intermediate (n=536), and high (n=331) ischemic risk. Analogous bleeding rates were 11.0, 23.9, and 66.2, respectively, among low (n=728), intermediate (n=634), and high (n=135) bleeding risk patients. Mean per event costs were $22 174 (ischemic) and $12 203 (bleeding). When risks for ischemia matched or exceeded bleeding, simulated utility-weighted event rates favored ticagrelor/prasugrel, whereas clopidogrel reduced utility-weighted events when bleeding exceeded ischemic risk. One-year costs were sensitive to drug pricing assumptions, and risk-tailored treatment with either agent progressed from cost incurring to cost saving with increasing generic market share.

Conclusions: Tailoring antiplatelet therapy intensity to patient risk may improve health utility and could produce cost savings in the first year after percutaneous coronary intervention.

Clinical trial registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00998127.

Keywords: acute coronary syndrome; clopidogrel; hemorrhage; myocardial infarction; percutaneous coronary intervention.