Original article Prognostic utility of NT-proBNP in acute exacerbations of chronic pulmonary diseases Araceli Molina Medina a,1 , Marta Sanchez Marteles b,1 , Elisa Bermejo Sáiz a , Sandra Serrano Martínez c , Fernando Ruiz Laiglesia b , José A. Nieto Rodríguez a, ⁎, Juan I. Pérez-Calvo b a Internal Medicine Service, Hospital Virgen de la Luz, Cuenca, Spain b Internal Medicine Service, Hospital Clínico Universitario Lozano Blesa, Zaragoza, Spain c Clinical Laboratory, Hospital Virgen de la Luz, Cuenca, Spain abstract article info Article history: Received 1 October 2009 Received in revised form 13 June 2010 Accepted 2 December 2010 Available online 5 January 2011 Keywords: NT-proBNP Natriuretic peptides Cor pulmonale Chronic pulmonary diseases Prognosis Background: The prognostic value of NT-proBNP levels in patients admitted to hospital due to acute exacerbations of chronic pulmonary diseases (CPDs) is unknown. Setting: Internal Medicine units at two general hospitals. Methods: NT-proBNP levels were obtained within 72 h after admission in 192 consecutive patients with acute exacerbations of CPDs and no history of heart failure or diuretic treatment. Clinical characteristics and main outcomes were assessed over a 12-month follow-up. NT-proBNP cut-points for outcomes were obtained by ROC (receiver operating characteristics) curve analysis. Results: Chronic obstructive lung disease (69.3%) and chronic asthma (22.4%) were the most prevalent CPDs, and non-pneumonic acute respiratory infection (72.4%) and pneumonia (22.9%) were the most frequent causes of exacerbation. Atrial flutter or fibrillation rate was 11%. During the one-year follow-up period, 22 patients died, 42 were re-admitted, 46 received new long-term oxygen therapy, and 39 received new diuretic treatment. NT-proBNP values correlated with hospitalisation days. NT-proBNP values over 587.9 pg/ml were associated with significantly raised one-year mortality (OR=3.90; 95% IC 1.46–10.47; p=0.006) and over 782.2 pg/ml with cardio-pulmonary deaths (OR=6.38; 95% IC 1.91–21.3; p=0.002). That association persisted after adjustment for age, gender, creatinine levels and cardiac rhythm. NT-proBNP values over 628.7 pg/ml were associated with significantly higher probability of new diuretic treatment (OR=4.38; IC 95% 2.07–9.25; p b 0.001). The negative predictive values for these cut-points ranged from 89% to 97%. Conclusion: NT-proBNP levels below 587.9 pg/ml in patients with acute exacerbations of CPD were associated with favourable one-year outcomes. © 2010 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. 1. Introduction B-type natriuretic peptides (BNP and NT-proBNP) are released by the heart to the bloodstream in response to increased ventricular volume or pressure [1,2]. B-type natriuretic peptides concentration correlates clearly with pulmonary capillary pressure [3], telediastolic intraventricular pressure and left ventricular ejection fraction [4,5]. There is also a weak-positive correlation between BNP concentration and main pulmonary arterial pressure, as assessed by echocardiogra- phy [6]. B-type natriuretic peptides have been used in clinical practice in the screening of patients with dyspnoea [7–9], asymptomatic ventricular dysfunction, and in the management of patients particu- larly those with cardiac diseases [10]. Moreover, B-type natriuretic peptides possess prognostic value for general and cardiovascular morbidity, even in patients without heart failure [11,12]. NT-proBNP levels have been less extensively studied in pulmonary diseases. Raised NT-proBNP levels have been found in patients with chronic pulmonary diseases (CPD) [13], cor pulmonare [6,14], and pulmonary embolism [15] as a consequence of pulmonary hyperten- sion [13]. As well as this, B-type natriuretic peptide is a short-term independent predictor of mortality in patients with CPD [13] and primary pulmonary hypertension [16]. We hypothesize that elevated NT-proBNP levels could help to stratify patients with acute exacerbations of CPD before they develop symptomatic right heart failure. The aim of the study was to determine the prognostic utility of NT-proBNP in that scenario. 2. Methods 2.1. Patients and setting Consecutive patients admitted to the hospital due to acute exacerbation of chronic pulmonary diseases and interviewed within European Journal of Internal Medicine 22 (2011) 167–171 ⁎ Corresponding author. Servicio de Medicina Interna, Donantes de Sangre 1., Hospital Virgen de la Luz, 16002 Cuenca, Spain. Tel.: +34 969 179900x58267; fax: +34 969 230407. E-mail address: joseanietor@terra.es (J.A.N. Rodríguez). 1 Both authors have made equal contributions to all the parts of the study. 0953-6205/$ – see front matter © 2010 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ejim.2010.12.002 Contents lists available at ScienceDirect European Journal of Internal Medicine journal homepage: www.elsevier.com/locate/ejim