Plasma N-terminal pro-brain natriuretic peptide concentrations may help to identify patients with very low-risk acute pulmonary embolism: A preliminary study.

Background: Patients with an acute pulmonary embolism (APE) are a heterogeneous group, and some of them may benefit from early discharge and an ambulatory care referral. We aimed to evaluate the use of N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma level assessment in patients with low-risk APE based on clinical findings (0 points on the simplified Pulmonary Embolism Severity Index (sPESI)).

Material and methods: Preliminary analysis of an ongoing prospective study including 1,151 normotensive patients with at least a segmental APE. In the final analysis, 348 patients with a 0-point sPESI were included. Blood samples were collected within the first 24 h of admission. The clinical endpoint (CE) included APE-related mortality and/or rescue thrombolysis in patients with clinical deterioration.

Results: Clinical endpoints occurred in 3 patients who had higher plasma NT-proBNP levels than study participants with a favorable clinical course (164 [64-650] pg/mL compared to 2,930 [2,285.5-13,965] pg/mL; p = 0.01). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) for NT-proBNP for the prediction of the CEs was 0.918 (95% confidence interval [95% CI]: 0.831-1.00; p = 0.013). We defined the cutoff value of NT-proBNP at ≥1,641 pg/mL.

Conclusions: Among subjects with 0 points on the sPESI, those with concentrations of NT-proBNP exceeding 1,641 pg/mL might require closer attention; remaining patients could be considered candidates for outpatient treatment. However, these findings warrant further investigation in a large, prospective group of patients.