Abstract
Background: The role of B-type natriuretic peptide (BNP) is less understood in the risk stratification of patients with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD), especially in patients with normal left ventricular ejection fraction (LVEF). Methods: This retrospective study from 2008 to 2012 evaluated all adult patients with AECOPD having BNP levels and available echocardiographic data demonstrating LVEF ≥40%. The patients were divided into groups 1, 2, and 3 with BNP ≤ 100, 101 to 500, and ≥501 pg/mL, respectively. A subgroup analysis was performed for patients without renal dysfunction. Outcomes included need for and duration of noninvasive ventilation (NIV) and mechanical ventilation (MV), NIV failure, reintubation at 48 hours, intensive care unit (ICU) and total length of stay (LOS), and in-hospital mortality. Two-tailed P <.05 was considered statistically significant. Results: Of the total 1145 patients, 550 (48.0%) met our inclusion criteria (age 65.1 ± 12.2 years; 271 [49.3%] males). Groups 1, 2, and 3 had 214, 216, and 120 patients each, respectively, with higher comorbidities and worse biventricular function in higher categories. Higher BNP values were associated with higher MV use, NIV failure, MV duration, and ICU and total LOS. On multivariate analysis, BNP was an independent predictor of higher NIV and MV use, NIV failure, NIV and MV duration, and total LOS in groups 2 and 3 compared to group 1. B-type natriuretic peptide continued to demonstrate positive correlation with NIV and MV duration and ICU and total LOS independent of renal function in a subgroup analysis. Conclusion: Elevated admission BNP in patients with AECOPD and normal LVEF is associated with worse in-hospital outcomes and can be used to risk-stratify these patients.