[Serum NT-proBNP levels are a prognostic predictor in patients with advanced heart failure]

Abstract

Objective: To verify if the determination of NT-proBNP values would help predict the prognosis in advanced heart failure (HF) patients.

Methods: One hundred and five subjects with average age of 52.4 years were evaluated, 66.6% of them males. Thirty-three (32.0%) subjects were outpatients and 70 (67.9%) were inpatients (functional class III/IV) admitted to the hospital for cardiac compensation. All patients had left ventricular systolic dysfunction and a mean ejection fraction of 0.29. The NT-proBNP levels were measured in all patients and they were followed-up over a period from 2 to 90 days (average 77 days). A ROC curve was drawn to determine the best cut-off point, as well as the corresponding Kaplan-Meyer survival curves.

Results: During the follow-up period, 22 patients died. The average NT-proBNP value of the patients who remained alive was 6,443.67+/-6,071.62 pg/ml, whereas that of those who died was 14,609.66+/-12,165.15 pg/ml (p=0.001). The ROC curve identified a cut-off point at 6,000 pg/ml with 77.3% sensitivity (area under the curve: 0.74). The survival curve for values below and above 6,000 pg/ml was significantly different (p=0.002): patients with values below 6,000 pg/ml had a 90.2% 90-day survival, and those patients with values above, a 66% survival.

Conclusion: Patients with advanced HF, especially those admitted to the hospital for cardiac compensation, had much higher NT-proBNP values, with a two-fold increase among those who died during the follow-up period. Values above 6,000 pg/ml identify the patients most likely to die within 90 days after hospital discharge.