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

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%).