Renin-angiotensin blockade in heart failure with preserved ejection fraction: a systematic review and meta-analysis.

Studies with angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin receptor blockers (ARBs) in patients with heart failure with preserved ejection fraction (HFpEF) have yielded inconsistent results. To conduct a systematic review and meta-analysis of all evidence for ACE-I and ARBs in patients with HFpEF, we searched PubMed, Ovid SP, Embase, and Cochrane database to identify randomized trials and observational studies that compared ACE-I or ARBs against placebo or standard therapy in HFpEF patients. Random-effect models were used to pool the data, and I testing was performed to assess the heterogeneity of the included studies. A total of 13 studies (treatment arm = 8676 and control arm = 8608) were analysed. Pooled analysis of randomized trials for ACE-I and ARBs (n = 6) did not show any effect on all-cause mortality [relative risk (RR) = 1.02, 95% confidence interval (CI) = 0.93-1.11, P = 0.68, I  = 0%], while results from observational studies showed a significant improvement (RR = 0.91, 95% CI = 0.87-0.95, P = 0.005, I  = 81.5%). In pooled analyses of all studies, ACE-I showed a reduction of all-cause mortality (RR = 0.91, 95% CI = 0.87-0.95, P = 0.01). There was no reduction in cardiovascular mortality seen, but in pooled analysis of randomized trials, there was a trend towards reduced HF hospitalization risk (RR = 0.91, 95% CI = 0.83-1.01, I  = 0%, P = 0.074). These data suggest that ACE-I and ARBs may have a role in improving outcomes of patients with HFpEF, underscoring the need for future research with careful patient selection, and trial design and conduct.