Original Research
Tuesday, October 15, 2024
08:30 AM–10:00 AM
Abstract
Introduction: Patients who undergo coronary artery bypass graft (CABG) surgery remain at high risk for major adverse cardiovascular events (MACE). The effect of P2Y12 inhibitors in this patient population is equivocal.
Research Question or Hypothesis: In patients who undergo CABG surgery, does exposure to a P2Y12 inhibitor, as compared to no exposure, reduce MACE?
Study Design: Population-based, propensity-weighted, retrospective cohort study using data from linked administrative databases in the province of British Columbia (BC), Canada. These databases include all cardiac revascularization procedures, hospital admissions, and prescription data for the entire population of BC (~5 million people).
Methods: Included were all adults who underwent CABG surgery in BC between 2002-2020. Patients who underwent CABG surgery <10 years or filled a prescription for a P2Y12 inhibitor <12 months before surgery were excluded. Primary exposure was prescription for a P2Y12 inhibitor <30 days post-surgery. Primary outcome was time to MACE (composite of all-cause death, nonfatal myocardial infarction, and nonfatal ischemic stroke). Adherence was assessed using proportion of days covered (PDC). Data were analyzed using Cox proportional hazards models with propensity weighting.
Results: In total, 15,439 patients were included. Mean age was 66 years, 83% were male, and 57% had a previous myocardial infarction. Sixteen percent were prescribed a P2Y12 inhibitor (83% clopidogrel) with median exposure time of 23 months. Ninety-seven percent were on a statin and 95% were on a beta-blocker. After propensity weighting and adjustment for relevant covariates, exposure to a P2Y12 inhibitor significantly lowered MACE at 1 year (hazard ratio 0.39, 95% confidence interval 0.27-0.55) and 5 years of follow-up (hazard ratio 0.65, 95% confidence interval 0.54-0.79). A PDC of =80% versus <80% did not impact these results.
Conclusion: Exposure to a P2Y12 inhibitor (primarily clopidogrel) reduced the hazard of MACE in patients after CABG surgery. These results support use of P2Y12 inhibitors as routine preventive therapy in post-CABG surgery patients.
Presenting Author
Arden Barry BSc, BSc(Pharm), PharmD, ACPRUniversity of British Columbia
Authors
Hamed Helisaz PhD
The University of British Columbia
Peter Loewen BSc(Pharm), PharmD, ACPR, FCSHP
University of British Columbia
Abdollah Safari PhD
GranTAZ Consulting