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.
Subject(s)
Dyspnea/blood , Dyspnea/mortality , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Renal Insufficiency/blood , Renal Insufficiency/mortality , Acute Disease , Age Distribution , Aged , Aged, 80 and over , Cause of Death , Creatinine/blood , Female , Hospitalization , Humans , Kaplan-Meier Estimate , Male , Multivariate Analysis , Predictive Value of Tests , Proportional Hazards Models , Prospective Studies , Risk FactorsABSTRACT
BACKGROUND: B-type peptide assay (brain natriuretic peptide [BNP] and N-terminal prohormone brain natriuretic peptide [NT-proBNP]) is useful for the diagnosis of heart failure (HF), but few data are available on the use of these markers in elderly subjects. The aim of this study was to evaluate NT-proBNP assay for the diagnosis of acute left HF in patients older than 70 years hospitalized for acute dyspnea. METHODS: We prospectively enrolled 256 elderly patients with acute dyspnea. They were categorized by 2 cardiologists unaware of NT-proBNP values into a cardiac dyspnea subgroup (left HF) and a noncardiac dyspnea subgroup (all other causes). RESULTS: Mean age was 81 +/- 7 years, and 52% of the patients were women. The diagnoses made in the emergency setting were incorrect or uncertain in 45% of cases. The median NT-proBNP value was higher (P < .0001) in patients with cardiac dyspnea (n = 142; 7906 pg/mL) than in patients with noncardiac dyspnea (n = 112; 1066 pg/mL). The area under the receiver operating characteristic curve was 0.86 (95% CI 0.81-0.91). At a cutoff of 2000 pg/mL, NT-proBNP had a sensitivity of 86%, a specificity of 71%, and an overall accuracy of 80% for cardiac dyspnea. The use of 2 cutoffs (< 1200 and > 4500 pg/mL) resulted in an 8% error rate and a gray area englobing 32% of values. CONCLUSION: NT-proBNP appears to be a sensitive and specific means of distinguishing pulmonary from cardiac causes of dyspnea in elderly patients. An optimal diagnostic strategy requires the use of 2 cutoffs and further investigations of patients with values in the gray area.
