Renin-angiotensin-aldosterone inhibition improves right ventricular function: a meta-analysis

The benefits of inhibiting the renin-angiotensin-aldosterone system (RAAS) are well established for left ventricular dysfunction, but remain unknown for right ventricular (RV) dysfunction. The aim of the current meta-analysis is to investigate the role of RAAS inhibition on RV function in those with or at risk of RV dysfunction. Medline, PubMed, EMBASE and Cochrane Libraries were systematically searched and 12 studies were included for statistical synthesis, comprising 265 RAAS inhibition treatment patients and 265 placebo control patients. The treatment arm showed a trend towards increased RV ejection fraction (weighted mean difference (WMD)=0.95, 95% CI -0.12 to 2.02, p=0.08) compared with the control arm. Subgroup analysis demonstrated a trend towards improvement in RV ejection fraction in patients receiving angiotensin receptor blockers compared with control (WMD=1.11, 95% CI -0.02 to 2.26, p=0.06), but not in the respective comparison for ACE inhibitors (WMD=0.07, 95% CI -2.74 to 2.87, p>0.05). No differences were shown between the two groups with regard to maximal oxygen consumption, RV end-systolic volume, RV end-diastolic volume, duration of cardiopulmonary exercise testing, and resting and maximal heart rate. Mild adverse drug reactions were common but evenly distributed between the treatment and control groups. The current meta-analysis highlights that there may be a role for RAAS inhibition, particularly treatment with angiotensin receptor blockers, in those with or at risk of RV dysfunction. However, further confirmation will be required by larger prospective trials.