The Impact of Renin–Angiotensin System Inhibitors on Postoperative Outcomes Following Coronary Artery Bypass Grafting

Patients undergoing coronary artery bypass grafting (CABG) remain at high risk of major adverse cardiovascular events and death despite successful revascularization, and the role of renin-angiotensin system inhibitors (RASi), comprising angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, in this setting is not clearly defined. We systematically reviewed the effect of RASi initiated within 30 days after CABG on postoperative outcomes. PubMed, Web of Science, Scopus, and the Cochrane Library were searched through May 2025 for randomized controlled trials and observational studies comparing patients who received RASi after CABG, alone or with other cardiovascular medications, with those who did not. Five studies (3 RCTs and 2 retrospective cohorts) comprising 47,821 patients (28,917 RASi recipients and 18,904 controls) were included. RASi use after CABG was generally associated with a lower rate of major adverse cardiovascular events, with the largest reductions observed in patients with heart failure. The effect on all-cause mortality was inconsistent: 2 studies reported a reduced risk, whereas 2 reported no significant difference. Cardiovascular mortality findings were similarly variable, with 1 study showing a marked reduction, 1 an early increase in the composite endpoint that attenuated over longer follow-up, and 1 no significant change.