Effect of P2Y12 Inhibitors on Major Adverse Cardiovascular Events After Coronary Artery Bypass Graft Surgery A Population Based Cohort Study summary

This PACUPod episode summarizes Barry et al.'s population-based cohort study on the impact of post-CABG P2Y12 inhibitors (primarily clopidogrel) on major adverse cardiovascular events. Using data from British Columbia (2002–2020) involving over 15,000 adults undergoing isolated CABG, exposure was defined as filling a P2Y12 inhibitor prescription within 30 days after surgery, compared with aspirin alone or no antiplatelet therapy. The primary outcome was time to first MACE (all-cause death, nonfatal MI, or nonfatal ischemic stroke) with up to five years of follow-up, and secondary outcomes included individual MACE components and an extended MACE definition. Inverse probability treatment weighting was employed to adjust for confounders. Results showed a 61% relative reduction in MACE risk at one year (hazard ratio 0.39; 95% CI 0.27–0.55) and a sustained ~35% reduction at five years, along with lower hazards for all-cause and cardiovascular death and the extended MACE outcome. Adherence, as measured by proportion of days covered, did not significantly modify outcomes, suggesting early initiation post-CABG is key. The episode discusses clinical implications for routine early initiation of P2Y12 inhibitors (mainly clopidogrel) in combination with aspirin, the need for multidisciplinary coordination to balance ischemic protection with bleeding risk, and remaining knowledge gaps about optimal duration and comparisons with other P2Y12 inhibitors. Limitations include the observational design, residual confounding, and exposure based on prescription fills rather than confirmed ingestion.