Cardiac biomarkers for outcome prediction in infant bronchiolitis: Too soon to discard troponin?

Background: Acute bronchiolitis, usually caused by the respiratory syncytial virus, is the most common cause of severe respiratory distress in infants. The clinical relevance of cardiac biomarkers for diagnosis and prognosis of bronchiolitis in infants is still controversial. Aim: This Editorial discuss the results of a recent on the clinical relevance of cardiac specific biomarkers, NT-proBNP and cardiac troponin I (cTnI) in 40 infants with bronchiolitis, 37% requiring admission in the ICU. Results: NT-proBNP levels were significantly associated with prolonged hospitalization and duration of oxygen therapy, while cTnI levels, measured with high-sensitivity (hs) methods, did not. Furthermore NT-proBNP was significantly correlated with left and right ventricular functional echocardiographic parameters, while hs-cTnI was not associated with any echocardiographic parameter. Discussion: Recent results confirm that NT-proBNP assay has a crucial role in the diagnosis, prognosis and follow-up of patients with cardiac disease not only in adult, but even in pediatric age). On the other hand, the clinical usefulness of assay of hs-cTnI and hs-cTnT in pediatric cardiology, at present time, may be greatly limited by the lack of reliable reference intervals. Conclusions: Further well-designed multi-center studies are needed to more accurately evaluate the clinical relevance of cardio-specific biomarkers, and in particular of hs-cTnI and hs-cTnT assay, on prognosis of infants with bronchiolitis.