Admission NT-proBNP levels, renal insufficiency and age as predictors of mortality in elderly patients hospitalized for acute dyspnea

Abstract

Background Assay of baseline B-type peptide (BNP and NT-proBNP) is useful for heart failure (HF) prognostication. In contrast, the prognostic value of NT-proBNP assay performed on admission of elderly subjects for acute dyspnea is uncertain. The aim of this study was to determine the vital prognostic value of NT-proBNP assay and other relevant variables available on admission in elderly patients hospitalized for acute dyspnea. Methods 254 patients over 70 years of age who were initially hospitalized with acute dyspnea were prospectively studied. The log-rank test and Cox proportional-hazards regression models were used to determine the prognostic value of NT-proBNP and creatinine clearance, measured within 24 h of initial admission, as well as age, gender, vascular risk factors and other clinical variables. Results Mean age was 81 ± 7 years, and 52% of the patients were women. During a median follow-up of 34 months, 134 patients (55%) died and 9 patients (4%) were lost to follow-up. The median survival time was 25 months, and almost half the deaths occurred during the first 6 months. In multivariate analysis the following three variables were independently associated with mortality (shown with their accompanying hazard ratios (HR)): NT-proBNP > 2856 pg/mL (median), HR = 1.6[95%CI:1.3–5.2]; creatinine clearance < 30 mL/min, HR = 1.7[95%CI:1.2–2.5]; and age > 80 years, HR = 1.7[95%CI:1.1–2.6]. The median survival time among patients with an admission NT-proBNP level of > 2856 pg/mL (median) was 14 months, compared to > 36 months in the rest of the population. Conclusion The admission NT-proBNP level, age, and creatinine clearance are predictive of vital outcome in elderly patients hospitalized for acute dyspnea.