The impact of heart failure therapy in patients with mildly reduced ejection fraction: a network meta-analysis

Recent heart failure (HF) guidelines have re-classified HF patients with left ventricular ejection fraction (LVEF) between 41% and 49% as HF with mildly reduced ejection fraction (HFmrEF). HFmrEF treatment is often considered a grey zone as no randomized controlled trials (RCTs) were conducted exclusively on these patients.

A network meta-analysis (NMA) was performed to compare treatment effect of mineralocorticoid receptor antagonists (MRA), angiotensin receptor neprilysin inhibitor (ARNi), angiotensin receptor blockers (ARB), angiotensin-converting-enzyme inhibitors (ACEi), sodium-glucose cotransporter-2 inhibitors (SGLT2i), and beta-blockers (BB) in HFmrEF cardiovascular (CV) outcomes.

RCTs sub-analyses evaluating the efficacy of pharmacological treatment in HFmrEF patients were searched. Hazard ratios (HRs) and their variance were extracted from each RCT for (i) composite of CV death or HF hospitalizations, (ii) CV death, and (iii) HF hospitalizations. A random-effects NMA was performed to compare and assess the treatment efficiency. Six RCTs with subgroup analysis according to participants' ejection fraction, a patient-level pooled meta-analysis of two RCTs, and an individual patient-level analysis of eleven BB RCTs were included, totalling 7966 patients. To our primary endpoint, SGLT2i vs. placebo was the only comparison with significant results, with a 19% risk reduction in the composite of CV death or HF hospitalizations [HR 0.81, 95% confidence interval (CI) 0.67-0.98]. In HF hospitalizations, the impact of the pharmacological therapies was more notorious, and ARNi reduced in 40% the risk of HF hospitalizations (HR 0.60, 95% CI 0.39-0.92), SGLT2i in 26% (HR 0.74, 95% CI 0.59-0.93) and renin-angiotensin system inhibition (RASi) with ARB and ACEi in 28% (HR 0.72, 95% CI 0.53-0.98). Although BBs were globally less beneficial, they were the only class that supported a reduced risk of CV death (HR vs. placebo: 0.48, 95% CI 0.24-0.95). We did not observe a statistically significant difference in any comparison between active treatments. There was a sound reduction with ARNi on the primary endpoint (HR vs. BB: 0.81, 95% CI 0.47-1.41; HR vs. MRA 0.94, 95% CI 0.53-1.66) and on HF hospitalizations (HR vs. RASi 0.83, 95% CI 0.62-1.11; HR vs. SGLT2i 0.80, 95% CI 0.50-1.30).

In addition to SGLT2i, pharmacological treatment recommended for HF with reduced LVEF, namely, ARNi, MRA, and BB, can also be effective in HFmrEF. This NMA did not show significant superiority over any pharmacological class.