Brain natriuretic peptide measurement in patients with COPD and cardiovascular disease.

We read with great interest the recent article by Maclay and MacNee 1 in CHEST (March 2013). The authors discussed different potential mechanisms that link COPD to an increased risk of cardiovascular disease, which will be the focus of novel therapeutic targets in the near future. We feel, however, that the relation among brain natriuretic peptide (BNP), COPD, and cardiovascular disease must be addressed. It is well established that COPD is associated with increased cardiovascular mortality and ventricular dysfunction. 2 In a 2011 prospective cohort study, 2 the prevalence of ventricular dysfunction among patients with COPD was 17%, with an increased risk of mortality during the 2-year follow-up period (hazard ratio, 2.34; P 5 .053). BNP has been proposed as a noninvasive marker to detect previously unknown left ventricular dysfunction in patients with acute exacerbation of COPD. A 2010 prospective study in a cohort of patients with acute exacerbation of COPD found a strong correlation between levels of N-terminal pro-BNP and early mortality. 3 In addition, BNP is an independent predictor of endothelial dysfunction. 4 Therefore, using BNP as a surrogate marker in patients with COPD may help identify patients with underlying cardiovascular disease. The physician has to keep in mind that the natriuretic peptide level elevation in this setting is much more discrete that the one found in overt left ventricular failure. 5