Zuin and colleagues are to be commended for their rigorous reappraisal of sodium–glucose co-transporter 2 inhibitor (SGLT2i) trials in heart failure with preserved and mildly reduced ejection fraction (HFpEF/HFmrEF) using fragility-based metrics alongside conventional effect estimates [1]. By systematically applying the fragility index, reverse fragility index, and related measures to EMPEROR-Preserved and DELIVER, they provide a nuanced view of endpoint stability, confirming that reductions in heart failure hospitalizations are consistent and statistically robust, whereas mortality benefits in these phenotypes remain uncertain.
