Department of Internal Medicine and Hypertension, University of Medicine in Warsaw, Banacha 1a, Warsaw 02-097, Poland
* Corresponding author. Tel.: +48-22-6597-506; fax: +48-22-6593-373
E-mail address: piotr.pruszczyk{at}amwaw.edu.pl
To the Editor
It was a great interest to read the review article on clinical implications of B-type natriuretic peptide testing published by Cowie et al.1 It is generally accepted that BNP and NTproBNP can improve the diagnosis of congestive heart failure. Authors underlined that elevated levels of these peptides help to differentiate heart failure from other causes of acute dyspnoea. In addition that, the assessment of these biomarkers may help to stratify prognosis not only in congestive heart failure but also in other cardiac disorder such as acute coronary syndromes. However, since BNP is released upon myocardial stretch, it can be expected that not only left ventricular strain but also overload of right ventricle (RV) may result in the elevation of BNP levels. Acute pulmonary embolism (APE) is frequently accompanied not only by sudden dyspnoea, but also by RV dysfunction. Recently, several papers have been published on BNP in APE. Kucher et al. observed BNP 90 pg/ml in almost half of patients with APE. Moreover, BNP levels helped to stratify short term outcome. Receiver operating characteristics analysis identified value of 50 pg/ml below which NPV for serious adverse events was 96%.2 Of interest, BNP was found to be a predictor of 3 months mortality in hemodynamically stable patients with APE. Subjects with BNP levels in the highest tertile (
21.7 pmol/L) had the poorest outcome.3 NTproBNP was also elevated in patients with APE and reflected its clinical severity.4 Moreover, we found significant correlations between echocardiographic indices of RV overload and NTproBNP levels.4 Interestingly, similarly to BNP, low levels of NTproBNP were found to predict favorable outcome.4,5
In conclusion, we should remember that patients with dyspnoea and elevated BNP not necessary suffer from congestive heart failure because both BNP and NTproBNP can be elevated in the majority of patients with APE which is accompanied by RV overload. Therefore, pulmonary embolism should be considered in the differential diagnosis of patients with dyspnoea and abnormal levels of brain natriuretic peptides. Moreover, levels of NTproBNP reflect the degree of RV overload in patients with APE. Importantly, both biomarkers may help to stratify short term prognosis in acute pulmonary embolism.
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