The ability of NT-proBNP to detect chronic heart failure and predict all-cause mortality is higher in elderly Chinese coronary artery disease patients with chronic kidney disease

OBJECTIVE To analyze the relationship between N-terminal pro-brain natriuretic peptide (NT-proBNP) and renal function, and compare the ability and cut-off thresholds of NT-proBNP to detect chronic heart failure (CHF) and predict mortality in elderly Chinese coronary artery disease (CAD) patients with and without chronic kidney disease (CKD). METHODS The study included 999 CAD patients older than 60 years. The endpoint was all-cause mortality over a mean follow-up period of 417 days. RESULTS The median age was 86 years (range: 60-104 years), and the median NT-proBNP level was 409.8 pg/mL. CKD was present in 358 patients. Three hundred and six patients were positive for CHF. One hundred and ten CKD patients and 105 non-CKD patients died. Not only CKD, but also estimated glomerular filtration rate independently affected NT-proBNP. NT-proBNP detected CHF with a cut-off value of 298.4 pg/mL in non-CKD patients and a cut-off value of 435.7 pg/mL in CKD patients. NT-proBNP predicted death with a cut-off value of 369.5 pg/mL in non-CKD patients and a cut-off value of 2584.1 pg/mL in CKD patients. The NT-proBNP level was significantly related to the prevalence of CHF and all-cause mortality in CAD patients with and without CKD; this effect persisted after adjustment. The crude and multiple adjusted hazard ratios of NT-proBNP to detect CHF and predict mortality were significantly higher in patients with CKD compared with the remainder of the population. The addition of NT-proBNP to the three-variable and six-variable models generated a significant increase in the C-statistic. CONCLUSION Amongst elderly Chinese CAD patients, there was an independently inverse association between NT-proBNP and renal function. With the higher cutoff points, NT-proBNP better detected CHF and better predicted mortality in CKD patients than in non-CKD patients.