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.