Usefulness of NT-proBNP serum level in the diagnosis of dyspnea in COPD patients

Introduction. Cardiovascular diseases often coexist with chronic obstructive pulmonary disease (COPD), and in some cases it is difficult to differentiate between cardiac and pulmonary cause of dyspnoea. It is well known that the serum concentration of NT-proBNP in patients with cardiovascular diseases, especially with congestive heart failure, is elevated. The aim of this study was to estimate the usefulness of NT-proBNP serum level measurement in patients with COPD complaining of chronic dyspnoea. Material and methods. The study group consisted of 81 stable COPD patients in middle age, 65 ± 7 years, (57 of them with concomitant cardiovascular disease). Serum concentration of NT-proBNP was measured using VITROS laboratory test. Results. There were no statistical differences in serum NT-proBNP between patients stratified according to the GOLD staging system for COPD severity or BODE index and mMRC breathlessness scale. The concentration of NT-proBNP was statistically significantly higher in the patients with coexisting cardiovascular diseases (220.8 ± 258.1 vs. 95.4±56.1 pg/ml). The group of patients with NT-proBNP concentration > 125 pg/ml (n = 36) was statistically significantly older (67.5 ± 6 years old vs. 63.2 ± 7.1 years old; p = 0.009) and had statistically significantly lower PaO2 (67.4 ± 11.8 mm Hg vs. 73.0 ± 11.6 mm Hg; p = 0.04). Conclusions. 1. In the group of stable COPD patients there were no differences between NT-proBNP serum concentration according to GOLD staging, BODE index, and mMRC breathlessness scale. 2. The NT-proBNP serum concentration was statistically significantly higher in the group of COPD patients with the concomitant cardiovascular disease. 3. In patients with chronic dyspnoea testing of serum NT-proBNP may be useful in the detection of patients with cardiovascular problems, who require more intensive therapy.