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

Natriuretic Peptide assays revisited do we need pro-B-type natriuretic Peptide?

Discovery of the endocrine function of the heart, which exerts a fundamental role in regulating cardiovascular homeostasis through atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), has opened up a new field of research that has resulted in multiple clinical applications

Free serum cortisol during the postoperative acute phase response determined by equilibrium dialysis liquid chromatography-tandem mass spectrometry

In severely ill patients low concentrations of the corticosteroid binding globulin are typically found; the aim of this study was to quantify directly free bioactive cortisol concentrations in the sera of postoperative cardiosurgical patients. Serum samples of 12 consecutive patients undergoing aortocoronary bypass surgery taken preoperatively and on the postoperative days 1 to 4 were analyzed. Total serum cortisol was quantified using liquid chromatographytandem mass spectrometry with an online sample extraction system and trideuterated cortisol as the internal standard, and free serum cortisol was measured after overnight equilibrium dialysis. Whereas on the first postoperative day, the median total serum cortisol concentration was approximately twofold increased compared to preoperative samples (preoperatively, 245 nmol/l (interquartile range (IQR) 203293 nmol/l); first postoperative day, 512 nmol/l (IQR 410611 nmol/l)), median dialyzable free cortisol concentration was almost sevenfold increased (preoperatively, 14.2 nmol/l (IQR 10.920.7 nmol/l); first postoperative day, 98.3 nmol/l (IQR 81.3134 nmol/l)). On the fourth postoperative day, median free cortisol was still significantly increased compared to baseline sampling (p < 0.05), whereas median total cortisol was not. A median of 5.7% (IQR 5.47.0%) of total cortisol was found as free cortisol on the preoperative day, 21.2% (IQR 18.9 23.5%) on the first postoperative day and 10.5% (IQR 9.814.0%) on the fourth postoperative day. It is concluded that during the postoperative period the freeto bound ratio of cortisol is highly variable and that during the acute phase response direct quantification of free bioactive cortisol concentrations seems to be biologically more appropriate than the measurement of total cortisol concentrations