NPPB and type 2 diabetes mellitus: In a prospective observational study [92], propensity score-matched, including 847 stable patients with advanced HFrEF (67.7% New York Heart Association [NYHA] III/IV, left ventricular ejection fraction [LVEF] 23.6 ± 5.8%) followed for a median of 3.1 years, the subgroup of patients treated with metformin (22.9% of patients with T2D in the study) had better event-free survival even after adjustment for brain natriuretic peptide (BNP), BMI, and eGFR (HR 0.70, 95% CI 0.50 to 0.98, P = 0.035).