Clinical Impact of N-Terminal Prohormone of Brain Natriuretic Peptide on Patients Hospitalized with Community-Acquired Pneumonia

The prognostic value of NT-proBNP in 28-day mortality and post-discharge survival in pneumonia: a retrospective cohort study from Taiwan

BACKGROUND

NT-proBNP, traditionally used to assess heart failure, is increasingly recognized for its prognostic value in other diseases. This study evaluates its value in pneumonia.

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study of adult patients hospitalized for pneumonia at Wan Fang Hospital (2017-2021) to investigate whether elevated NT-proBNP levels predicted poorer outcomes. Logistic regression identified risk factors for 28-day mortality, while the Cox regression model identified predictors of post-discharge survival.

RESULTS

Among 2,805 patients (79.6 ± 13.4 years, female 45%), the 28-day mortality rate was 18.2%, and the median post-discharge follow-up time was 359 days. Moderately (increased but < 10000 pg/mL) and severely (>10000 pg/mL) elevated NT-proBNP levels had higher 28-day mortality compared to normal NT-proBNP; adjusted odds ratios: 2.24 (1.34-3.75, p = 0.002) and 3.57 (2.03-6.27, p < 0.001). Moderately and severely elevated NT-proBNP levels related to shorter survival time than normal NT-proBNP levels; adjusted hazard ratios 1.60 (1.28-2.00, p < 0.001) and 2.03 (1.56-2.63, p < 0.001). All ratios were adjusted with comorbidities, sex, age, and clinical and laboratory tests.

CONCLUSIONS

Elevated NT-proBNP levels predict higher 28-day mortality and shorter survival time in patients with pneumonia across most subpopulations. This marker holds potential as a prognostic biomarker for pneumonia, especially in high-risk patients.

N-terminal Pro-B-Type Natriuretic Peptide is a Myocardial Biomarker in Pulmonary Sepsis and Septic Shock

The objective: to study changes and prognostic significance of the blood NT-proBNP in the patients with pulmonary sepsis.

Subjects and Methods. The study included 34 patients aged 54.5 ± 2.9 years with pulmonary sepsis or septic shock. Lethality in the intensive care unit (ICU) was 47.1%. NT-proBNP, procalcitonin (PCT) levels, blood lactate and hemodynamic parameters were registered on the 1st day (stage 1) and on the 4th-5th day of the ICU stay (stage 2). Hemodynamics was assessed through transpulmonary thermodilution. The differences were considered statistically significant at p < 0.05.

Results: At stage 1, NT-proBNP level was 5,220 [1,380‒17,850] pg/ml, did not decrease (p = 0.726) at stage 2 and amounted to 1,760 [631‒847] pg/ml. At stage 1, NT-proBNP correlated with extravascular lung water index (rho = 0.445; p = 0.038) and systolic pulmonary artery pressure (rho = 0.414; p = 0.023). At stage 2, NT-proBNP correlated with PCT (rho = 0.569; p = 0.003), blood lactate (rho = 0.525; p = 0.001), and mean arterial pressure to norepinephrine dosage ratio (rho = -0.422; p = 0.035). At stage 1, NT-proBNP was no predictor of lethality in the ICU: OR 1.0000; 95% CI 1.0000-1.0001. At stage 2, NT-proBNP > 4,260 pg/ml (sensitivity 87.5%, specificity 94.4%) was a predictor of lethality: OR 1.0004, 95% CI 1.0000-1.0008, p = 0.046 (AUC 0.893, 95% CI 0.732-0.974). Any increase of NT-proBNP level (> 0 pg/ml) between stages 2 and 1 was a predictor of lethality (sensitivity 87.5%, specificity 94.4%): OR 119.0, 95% CI 9.7432‒1,453.4241, p = 0.0002 (AUC 0.903, 95% CI 0.751-0.977).

Conclusion: Patients with pulmonary sepsis are characterized by a significant increase of blood NT-proBNP. At stage 1, the biomarker correlated with pulmonary hypertension and moderate pulmonary edema and was no predictor of lethality. At stage 2, NT-proBNP correlated with the indices of infection and sepsis severity (procalcitonin, blood lactate, and mean arterial blood pressure/norepinephrine dosage ratio). At this stage, NT-proBNP levels greater than 4,000 pg/mL and/or any degree of increase in blood levels of the biomarker were both sensitive and specific predictors of a lethal outcome. Specific features of etiopathogenesis of BNP hyperproduction in pulmonary sepsis make it difficult to interpret the elevation of NT-proBNP as an indicator of septic cardiomyopathy but does not reduce its value as a sensitive and specific predictor of lethality.

Prognostic factors in patients hospitalized with community-acquired aspiration pneumonia

INTRODUCTION

Patients with aspiration pneumonia (AP) exhibit higher mortality than those with non-AP. However, data regarding predictors of short-term prognosis in patients with community-acquired AP are limited.

METHODS

Patients hospitalized with community-acquired pneumonia (CAP) were retrospectively classified into aspiration pneumonia (AP) and non-AP groups. The AP patients were further divided into nonsurvivors and survivors by 30-day mortality, and various clinical variables were compared between the groups.

RESULTS

Of 1249 CAP patients, 254 (20.3%) were classified into the AP group, of whom 76 patients (29.9%) died within 30 days. CURB-65, pneumonia severity index (PSI), and Infectious Diseases Society of America/American Thoracic Society criteria for severe CAP (SCAP) showed only modest prognostic performance for the prediction of 30-day mortality (c-statistics, 0.635, 0.647, and 0.681, respectively). Along with the PSI and SCAP, Eastern Cooperative Oncology Group performance status (ECOG-PS) and blood biomarkers, including, N-terminal of prohormone brain natriuretic peptide (NT-proBNP) and albumin, were independent predictors of 30-day mortality. In models based on clinical prediction rules, including CURB-65, PSI, and SCAP, the addition of ECOG-PS further improved their c-statistics compared to the clinical prediction rules alone. In the four combinations based on SCAP, ECOG-PS, and two blood biomarkers (NT-proBNP and albumin), the c-statistics further increased to reach approximately 0.8.

CONCLUSIONS

CURB-65, PSI, and SCAP exhibited only modest discriminatory power in predicting the 30-day mortality of patients with community-acquired AP. The addition of performance status and blood biomarkers, including NT-proBNP and albumin, further increased prognostic performance, showing good predictive accuracy in the SCAP-based model.