NPPB and diabetes mellitus: HFrEF (LVEF ≤ 40%, NYHA class ≥ II, elevated NT-proBNP); mean age 66; 23% women; 42% with known diabetes, 3% undiagnosed; 94% on ACEI/ARB/ARNI, 96% on β-blockers, 71% on MRAs