Elevated plasma B-type natriuretic peptide and C-reactive protein levels in children with restrictive right ventricular physiology following tetralogy of Fallot repair.

OBJECTIVES

This study aimed to compare the levels of plasma B-type natriuretic peptide (BNP) and C-reactive protein (CRP) in relation to oxygen transport between patients with restrictive right ventricle (rRV) and those without (non-rRV) early after tetralogy of Fallot (TOF) repair.

METHODS

Eighty patients (30 in the rRV group) underwent TOF repair in 2011 and 2012. BNP and CRP were repeatedly measured during postoperative day (POD) 7, along with oxygen transport variables including arterial and superior vena cava oxygen saturation (SaO2 and SvO2 ), oxygen extraction ratio (ERO2 ), and lactate. Demographic data included age and durations of cardiopulmonary bypass (CPB), aortic cross-clamping (ACC), mechanical ventilation, and ICU and hospital stays.

RESULTS

During POD 7, BNP did not change in either of the two groups but was consistently higher in the rRV group (P < .0001). CRP increased from POD 1 to POD 2 and decreased thereafter. The decrease was slower in the rRV group (P = .04). The increase in SvO2 and the decrease in ERO2 were slower in the rRV group (P < .05). Lactate decreased in both groups (P < .05) but was consistently higher in the rRV group (P = .03). BNP was negatively correlated with SvO2 and preoperative SaO2 and positively correlated with ERO2 and lactate (P < .05). No correlation was found between CRP and oxygen transport variables. The rRV group was older and required longer CPB, ACC, mechanical ventilation, and ICU and hospital stays compared with the non-rRV group (P < .05 for all).

CONCLUSIONS

rRV physiology is associated with significantly higher BNP and CRP levels with poorer balance of systemic oxygen transport. Information about these pathophysiological changes may help to identify appropriate treatment strategies in this difficult group of patients.