Impact of Systemic Ventricular Morphology on Age-Adjusted (zlog-)NT-proBNP in Children with Univentricular Hearts

As a marker of cardiac wall stress, NT-proBNP offers high prognostic and diagnostic potential in patients with a functional single ventricle (fSV). Its levels depend on both age and stage of palliation. However, the impact of systemic ventricular morphology on this biomarker remains unclear. Children undergoing staged palliation, i.e. systemic-to-pulmonary shunt (SPS), ductal stenting (DS) and/or pulmonary artery banding (PAB) as stage 1, bidirectional cavopulmonary shunt (BCPS) as stage 2 or extracardiac total cavopulmonary connection (TCPC) as stage 3 at our institution between 2011 and 2023 were identified. Those, who had NT-proBNP determined at most 7 days before intervention or surgery were included. Furthermore, patients at least 6 months after TCPC with ambulatory measured NT-proBNP were enrolled. NT-proBNP levels were evaluated using its age-adjusted z-score ("zlog-NT-proBNP"), allowing comparison irrespective of the distinctive physiological decline with age. Overall, 618 children met the eligibility criteria. Thereof, 356 patients had a systemic right ventricle (SRV) and 262 a systemic left ventricle (SLV). At each stage of palliation, age-adjusted zlog-NT-proBNP was significantly higher in patients with an SRV compared to an SLV: before SPS/DS/PAB (median 3.43 vs 2.62, p < 0.001); before BCPS (median 3.33 vs 2.04, p < 0.001); before TCPC (median 1.50 vs 0.66, p < 0.001); and after TCPC (median 1.62 vs 0.81, p < 0.001). Systemic ventricular morphology highly affects (zlog-)NT-proBNP levels in fSV patients at each stage of palliation. When interpreting NT-proBNP levels in these patients, clinicians and future studies should take into account that children with an SRV reveal higher NT-proBNP levels than those with an SLV.