Meta-analysis of RAAS inhibition in patients with a systemic right ventricle.

INTRODUCTION: Pharmacological therapy has transformed the management of heart failure, yet pivotal trials have primarily focused on acquired left ventricular disease. Evidence for renin-angiotensin-aldosterone system (RAAS) inhibition in systemic right ventricle (sRV) remains scarce, and current practice is largely based on extrapolation from left ventricular studies and expert consensus. This meta-analysis evaluates the efficacy and safety of RAAS blockade in patients with a failing sRV. METHODS: A PubMed search identified studies investigating RAAS inhibition in sRV failure. Reported outcomes included changes in NT-pro-BNP, right ventricular ejection fraction (RVEF), and peak oxygen uptake (VO2-max). Data were analyzed using conventional statistics and visualized with forest plots. RESULTS: Ten eligible studies were included, comprising a pooled cohort of 325 patients, of which 261 received active treatment. The population was predominantly male (67.1%), with mean cohort ages ranging from 25.2 to 48.5 years. Mean treatment durations spanned 3.5 to 37.2 months. RAAS inhibition was associated with a reduction in NT-pro-BNP (Cohen's d = -0.28, 95% CI -0.49 to -0.07, p = 0.01). However, no improvements in RVEF or VO2-max were observed. The therapy was generally well-tolerated. The overall mortality incidence was 5.6 deaths per 1000 person-years in the active treatment groups. CONCLUSION: The evidence for RAAS inhibition in patients with sRV is limited but suggests a beneficial reduction in NT-pro-BNP, indicating a hemodynamic effect but without improvements in RVEF or VO2-max. When combined with extrapolated data from large left ventricular heart failure trials, these findings support that RAAS inhibition is safe and may be considered in patients with sRV failure.