Predictive Value of NT-proBNP in Vascular Surgery Patients with COPD and Normal Left Ventricular Systolic Function

ABSTRACT N-terminal pro-B-type natriuretic peptide (NT-proBNP) is commonly used to identify a cardiac cause of dyspnoea. However, patients with chronic obstructive pulmonary disease (COPD) may also have increased plasma NT-proBNP levels because of right-sided myocardial stress caused by pulmonary hypertension. We investigated the relationship between COPD and elevated NT-proBNP levels as well as the impact of elevated NT-proBNP levels on mortality in vascular surgery patients with normal left ventricular systolic function. Prior to vascular surgery, NT-proBNP levels, pulmonary function and left ventricular ejection fraction (LVEF) were assessed in 376 patients. Only patients with a LVEF > 40%% were included; n == 261. Elevated NT-proBNP levels were defined as ≥500 pg/ml. Firstly, we assessed the relationship between COPD and NT-proBNP levels. Secondly, we investigated the association between elevated NT-proBNP levels and one-year mortality. COPD was independently associated with elevated NT-proBNP levels (OR 3.36, 95%%CI 1.30-8.65) with significant associations found for mild and severe COPD. Elevated NT-proBNP levels were associated with increased one-year mortality in patients with (HR 7.73, 95%%CI 1.60-37.43) and without COPD (HR 3.44, 95%%CI 1.10-10.73). COPD was associated with elevated NT-proBNP levels in patients with a normal LVEF undergoing vascular surgery. Elevated NT-proBNP levels independent of other well-established risk factors were associated with increased one-year mortality. NT-proBNP may be useful biomarker to risk stratify patients with COPD.