Plasma activity of B-type natriuretic peptide in patients with biventricular heart failure versus those with right heart failure due to chronic obstructive pulmonary disease

Cardiovascular Comorbidities in Chronic Obstructive Pulmonary Disease (COPD)-Current Considerations for Clinical Practice

In patients with chronic obstructive pulmonary disease (COPD), cardiovascular comorbidities are highly prevalent and associated with considerable morbidity and mortality. This coincidence is increasingly seen in context of a “cardiopulmonary continuum” rather than being simply attributed to shared risk factors such as cigarette smoking. Overlapping symptoms such as dyspnea or chest pain lead to a worse prognosis due to missed concomitant diagnoses. Moreover, medication is often withheld as a result of unfounded concerns about side effects. Despite the frequent coincidence, current guidelines are still mostly restricted to the management of the individual disease. Future diagnostic and therapeutic strategies should therefore be guided by an integrative perspective as well as a refined phenotyping of disease entities.

Role of B-Type Natriuretic Peptide in Predicting In-Hospital Outcomes in Acute Exacerbation of Chronic Obstructive Pulmonary Disease With Preserved Left Ventricular Function: A 5-Year Retrospective Analysis

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.

Brain natriuretic peptide: Much more than a biomarker

Brain natriuretic peptide (BNP) modulates several biological processes by activating the natriuretic peptide receptor A (NPR-A). Atria and ventricles secrete BNP. BNP increases natriuresis, diuresis and vasodilatation, thus resulting in a decreased cardiac workload. BNP and NT-proBNP, which is the biologically inactive N-terminal portion of its pro-hormone, are fast and sensitive biomarkers for diagnosing heart failure. The plasma concentrations of both BNP and NT-proBNP also correlate with left ventricular function in patients with acute exacerbation of COPD, even without history of heart failure. Several studies have been conducted in vitro and in vivo, both in animals and in humans, in order to assess the potential role of the NPR-A activation as a novel therapeutic approach for treating obstructive pulmonary disorders. Unfortunately, these studies have yielded conflicting results. Nevertheless, further recent specific studies, performed in ex vivo models of asthma and COPD, have confirmed the bronchorelaxant effect of BNP and its protective role against bronchial hyperresponsiveness in human airways. These studies have also clarified the intimate mechanism of action of BNP, represented by an autocrine loop elicited by the activation of NPR-A, localized on bronchial epithelium, and the relaxant response of the surrounding ASM, which does not expresses NPR-A. This review explores the teleological activities and paradoxical effects of BNP with regard to chronic obstructive respiratory disorders, and provides an excursus on the main scientific findings that explain why BNP should be considered much more than a biomarker.