John J V McMurray

Background and aims Randomized controlled trials (RCTs) have assessed the effects of renin–angiotensin system (RAS) blockers in adults with coronavirus disease 2019 (COVID-19). This meta-analysis provides estimates of the safety and efficacy of treatment with (vs. without) RAS blockers from these trials. Methods PubMed, Web of Science, and ClinicalTrials.gov were searched (1 March–12 April 2023). Event/patient numbers were extracted, comparing angiotensin-converting enzyme (ACE) inhibitor/angiotensin-receptor blocker (ARB) treatment with no treatment, for the outcomes: intensive care unit (ICU) admission, mechanical ventilation, vasopressor use, acute kidney injury (AKI), renal replacement therapy (RRT), acute myocardial infarction, stroke/transient ischaemic attack, heart failure, thromboembolic events, and all-cause death. Fixed-effects meta-analysis estimates were pooled. Results Sixteen RCTs including 3492 patients were analysed. Compared with discontinuation of RAS blockers, continuation was not associated with increased risk of ICU [risk ratio (RR) 0.96, 0.66–1.41], ventilation (RR 0.77, 0.55–1.09), vasopressors (RR 0.92, 0.58–1.44), AKI (RR 1.01, 0.40–2.56), RRT (RR 1.01, 0.46–2.21), or thromboembolic events (RR 1.07, 0.36–3.19). RAS blocker initiation was not associated with increased risk of ICU (RR 0.71, 0.47–1.08), ventilation (RR 1.12, 0.91–1.38), AKI (RR 1.28, 0.89–1.86), RRT (RR 1.66, 0.89–3.12), or thromboembolic events (RR 1.20, 0.06–23.70), although vasopressor use increased (RR 1.27, 1.02–1.57). The RR for all-cause death in the continuation/discontinuation trials was 1.24 (0.80–1.92), and 1.22 (0.96–1.55) in the initiation trials. In patients with severe/critical COVID-19, RAS blocker initiation increased the risk of all-cause death (RR 1.31, 1.01–1.72). Conclusion ACE inhibitors and ARBs may be continued in non-severe COVID-19 infection, where indicated. Conversely, initiation of RAS blockers may be harmful in critically ill patients. PROSPERO registration number: CRD42023408926.