Indobufen Versus Aspirin After CABG for Unstable Angina in Patients Aged 70 Years and Older

Postoperative antiplatelet selection after coronary artery bypass grafting (CABG) in adults aged ≥70 years requires balancing ischemic protection against bleeding risk.

We conducted a single-center retrospective cohort study of adults aged ≥70 years who underwent isolated CABG for unstable angina between 2017 and 2021. The exposure was the initial discharge antiplatelet pathway: aspirin 100 mg once daily or indobufen 100 mg twice daily as the cyclooxygenase-inhibitor component, combined with a P2Y12 inhibitor during the first postoperative year and followed by the same cyclooxygenase inhibitor during the second year. Propensity scores were estimated using multivariable logistic regression with 16 prespecified baseline covariates, and stabilized inverse probability of treatment weighting (IPTW) was applied. The primary analyses used IPTW-weighted Cox models.

Among 336 screened patients, 79 were included in the final analytic cohort (aspirin-based pathway, n = 49; indobufen-based pathway, n = 30). After weighting, measured covariate balance improved, although residual imbalance remained for prior myocardial infarction and prior percutaneous coronary intervention. At 24 months, no statistically significant association was observed between pathway and MACCE (HR 0.858, 95% CI 0.257-2.866; p = 0.803), BARC grade ≥2 bleeding (HR 0.359, 95% CI 0.093-1.385; p = 0.137), or NACE (HR 0.526, 95% CI 0.204-1.360; p = 0.185). Graft surveillance was evaluable in 77/79 patients at 1 year and 71/79 at 2 years and was analyzed descriptively.

In this real-world cohort of older patients undergoing CABG for unstable angina, an initial indobufen-based discharge pathway was not statistically significantly associated with 24-month MACCE, BARC grade ≥2 bleeding, or NACE compared with an aspirin-based pathway after stabilized IPTW. These findings add exploratory CABG-specific data on indobufen in older patients and should be confirmed in larger prospective studies.