NPPB and chronic kidney disease: By univariate Cox hazard analysis, thirteen variables were identified as significant predictors (previous hospitalization for HF, ischemic heart disease, atrial fibrillation, hypertension, chronic kidney disease, LVEF, left atrium diameter, E/e’, LV mass index, serum sodium, hemoglobin, Ln-BNP, and sMg < 2.0 mg/dl).