We read with great interest the article by Zuin et al., which provides a rigorous evaluation of the robustness of randomized controlled trial (RCT) evidence for sodium-glucose co-transporter 2 inhibitors (SGLT2i) in heart failure with preserved (HFpEF) and mildly reduced ejection fraction (HFmrEF) [1]. By applying Fragility Index (FI) and Reverse Fragility Index (RFI) metrics to the pivotal EMPEROR-Preserved and DELIVER trials, the authors convincingly demonstrate that while the reduction in heart failure hospitalization (HFH) is statistically robust, the benefits regarding cardiovascular and all-cause mortality remain fragile.
