N-Terminal Pro-B-Type Natriuretic Peptide Predicts the Burden of Pulmonary Embolism

Background: In acute pulmonary embolism (PE), brain natriuretic peptides are markers of right ventricular dysfunction and they could point out the size of the occluded pulmonary vessel. Method : N-terminal pro-B-type natriuretic peptide (BNP) was measured in 93 consecutive outpatients diagnosed with acute PE by means of helical computed tomography. Central PE was diagnosed when thrombotic material was seen in the main trunk or right or left main branches of the pulmonary artery, and peripheral PE was diagnosed when thrombi were seen exclusively in segmental or subsegmental arteries. Results: Central PE occurred in 51 (55%) patients and peripheral PE in 42 (45%). Plasma level of pro-BNP greater than 500 ng/L was independently associated with central PE. The area under the receiver operating characteristic curve was 0.753 (CI 95% 0.7000.806), sensitivity 0.82 (CI 95% 0.69-0.91), specificity 0.67 (CI 95% 0.50-0.79), positive predictive value 0.75 (CI 95% 0.61-0.85), and negative predictive value 0.76 (CI 95% 0.58-0.87). Six (6%) patients died, 3 from PE, 2 from brain hemorrhage, and 1 from advanced gallbladder cancer. N-terminal pro-BNP level was greater than 500 ng/L in all patients who died. The area under receiver operating characteristic curve for death was 0.712 (CI 95% 0.635-0.789), sensitivity 0.10 (CI 95% 0.04-0.22), specificity 1 (CI 95% 0.88-1) positive predictive value 1 (CI 95% 0.51-1), and negative predictive value 0.42 (CI 95% 0.32-0.53). Conclusions: Preliminary data suggest that N-terminal pro-BNP levels higher than 500 ng/L could serve as indicator of the burden of PE and perhaps as a predictor of death.