Effect of early antiplatelet therapy on 30-day mortality after coronary artery bypass grafting: a retrospective target trial emulation using the MIMIC-IV database

Clinical Snapshot

Key Findings

• P Value: Not explicitly stated for primary outcome, CI excludes null

• Effect Size: Absolute risk difference: 0.90% (95% CI 0.09% to 1.72%)

• Primary Outcome: 30-day mortality: 2.35% (control) vs 1.44% (treatment)

• Nnt Or Sensitivity: Number needed to treat: approximately 111 patients to prevent one death

• Confidence Interval: 95% CI 0.09% to 1.72% for mortality difference

Clinical Application

Highly feasible - antiplatelet therapy is standard post-CABG care with established protocols Relevant to Australian cardiac surgery practice; antiplatelet agents are PBS-subsidised; aligns with CSANZ guidelines for post-CABG care Adult patients undergoing CABG in tertiary cardiac centres

Abstract

OBJECTIVES: The effect of early antiplatelet therapy on 30-day mortality after coronary artery bypass grafting (CABG) remains uncertain. This study aimed to evaluate the association between early antiplatelet therapy initiation and clinical outcomes in post-CABG patients. DESIGN: A retrospective target trial emulation. SETTING: Single academic medical centre in Boston, Massachusetts, USA. PARTICIPANTS: We included adult patients who underwent CABG and were admitted to the intensive care unit at Beth Israel Deaconess Medical Center between 2008 and 2022. METHODS: Patients were classified into the treatment group if they initiated antiplatelet therapy within 24 hours postoperatively; otherwise, they were assigned to the control group. To address immortal-time bias for the primary outcome of 30-day mortality, we used clone-censor-weighting. For the exploratory outcome of 30-day acute kidney injury (AKI) incidence, we employed inverse probability of treatment weighting to balance baseline covariates. RESULTS: The analysis for 30-day mortality included 6887 patients. The mortality was 2.35% in the control group versus 1.44% in the treatment group, yielding an absolute risk difference of 0.90% (control group minus treatment group, 95% CI 0.09% to 1.72%). The difference in restricted mean time lost was 0.19 days (control group minus treatment group, 95% CI 0.03 to 0.36). For AKI incidence, 5543 patients were analysed. The incidence was 78.61% in the control group and 69.13% in the treatment group, with an absolute difference of 9.48% (control group minus treatment group, 95% CI 6.40% to 12.50%; p<0.001). CONCLUSIONS: In this target trial emulation, early antiplatelet therapy initiated within 24 hours after CABG was associated with lower 30-day mortality and a reduced incidence of postoperative AKI. These findings warrant confirmation in prospective randomised controlled trials.

References

1. 1.Jiang, Y., Ding, H., Su, J., & Li, X. (2026). Effect of early antiplatelet therapy on 30-day mortality after coronary artery bypass grafting: a retrospective target trial emulation using the MIMIC-IV database. BMJ Open. https://doi.org/10.1136/bmjopen-2025-113901