Abstract 3171: Cardiovascular Outcomes with Removal of Clopidogrel Prior Authorization in Patients Receiving Coronary Stents Post-Myocardial Infarction
In Canada, governmental drug policy controls access to certain medications on provincial drug formularies. Drug reimbursement policy may adversely impact patient outcomes if it interferes with timely access to efficacious medications for acute medical conditions. Clopidogrel with aspirin is the recommended standard of care in patients receiving coronary stents to prevent thrombosis. We examined the population-level impact of a change in a government insurance program from a prior authorization (PA) to a limited use (LU) policy on access to clopidogrel in the setting of percutaneous coronary intervention (PCI) with stenting following acute myocardial infarction (AMI) and its association with cardiovascular outcomes. We conducted a population-based, retrospective, time-series analysis from April 1, 2000 to March 31, 2005 of 6,161 AMI patients, 65 years and older, who underwent PCI with stenting in one Canadian province. Data sources included the hospitalization discharge abstract database, the prescription claims database and the vital status database. The primary outcome was the 1-year sex- and age-adjusted composite rate of death, recurrent AMI, PCI and coronary artery bypass graft surgery. The secondary outcome was major bleeding. The rate of clopidogrel use within 30 days of AMI discharge increased from 35% to 88% in the PA and LU periods, while the median time to first clopidogrel prescription post-AMI discharge decreased from 9 to 0 days, respectively. The 1-year composite cardiovascular endpoint significantly decreased by 4% from the PA to the LU period (15% vs. 11%, respectively, p=0.015). Bleeding rates did not change between the PA and LU period. Improving timely access to clopidogrel for coronary stenting through the removal of a PA program was associated with improved cardiovascular outcomes without an increased risk of bleeding.