NPPB and chronic kidney disease: In the multivariable Cox proportional hazards model for the primary outcome, the mildly reduced EF group consistently had a better prognosis than the reduced EF group, after adjusting for age, sex, clinical risk factors (DM and CKD), admission status (STEMI, HR, NT-proBNP, and hemoglobin), and discharge medications (beta-blockers, RAS inhibitors, and statins).