Sodium‐glucose cotransporter 2 inhibitor effects on heart failure hospitalization and cardiac function: systematic review

AIMS: To systematically review randomized controlled trials assessing effects of sodium–glucose cotransporter 2 inhibitors (SGLT2is) on hospitalization for heart failure (HHF) and cardiac structure/function and explore randomized controlled trial (RCT)‐derived evidence for SGLT2i efficacy mechanisms in heart failure (HF). METHODS AND RESULTS: Systematic searches of Medline and Embase were performed. In seven trials [3730–17 160 patients; low risk of bias (RoB)], SGLT2is significantly reduced the relative risk of HHF by 27–39% vs. placebo, including in two studies in patients with HF with reduced ejection fraction with or without type‐2 diabetes mellitus (T2DM). Improvements in conventional cardiovascular risk factors, including glycaemic levels, cannot account for these effects. Five trials (56–105 patients; low RoB) assessed the effects of 6–12 months of SGLT2i treatment on left ventricular structure/function; four reported significant improvements vs. placebo, and one did not. Five trials (low RoB) assessed SGLT2i treatment effects on serum N‐terminal pro B‐type natriuretic peptide levels; significant reductions vs. placebo were reported after 8–12 months (two studies; 3730–4744 patients) but not ≤12 weeks (three studies; 80–263 patients). Limited available RCT‐derived evidence suggests various possible cardioprotective SGLT2i mechanisms, including improved haemodynamics (natriuresis and reduced interstitial fluid without blood volume contraction/neurohormonal activation) and vascular function, enhanced erythropoiesis, reduced tissue sodium and epicardial fat/inflammation, decreased sympathetic tone, and beneficial changes in cellular energetics. CONCLUSIONS: Sodium–glucose cotransporter 2 inhibitors reduce HHF regardless of T2DM status, and reversal of adverse left ventricular remodelling likely contributes to this efficacy. Hypothesis‐driven mechanistic trials remain sparse, although numerous trials are planned or ongoing.