Age-adjusted zlog-NT-proBNP—A Reliable Marker to Detect Recurrent Aortic Arch Obstruction in Children after the Norwood Procedure

Background: Recoarctation following the Norwood procedure is a frequent complication in children with univentricular hearts (UVHs). If detected late or left untreated, it is associated with increased mortality. Therefore, we sought to evaluate the ability of age-adjusted zlog-NT-proBNP, a marker of cardiac wall stress, to identify patients with recurring aortic obstruction during Interstage-I.

Methods: All children with UVHs after systemic-to-pulmonary (SP) shunt placement and concomitant aortic arch reconstruction (stage-1-palliation, S1P) undergoing heart catheterization prior to bidirectional cavopulmonary shunt (BCPS, S2P) at the German Heart Center Munich between April 2013 and December 2023 were enrolled. zlog-NT-proBNP measurements were obtained before patient dismission following S1P, as well as before and after catheterization prior to S2P.

Results: A total of 142 children met the inclusion criteria. The majority (85%, n = 121) had a dominant right ventricle and 64% (n = 91) had a modified Blalock–Taussig shunt. A total of 252 cardiac catheterizations were performed at a median time of 60 days (IQR, 14–90) after S1P. In 62 catheterizations (of 48 patients), an intervention (dilatation and/or stent) for recoarctation was necessary. Therefore, 46 (74%) catheter interventions were due to a peak-to-peak gradient of ≥10 mm Hg over the aortic arch or isthmus. Children with intervention for recoarctation revealed significantly higher zlog-NT-proBNP levels compared with those without (median, 4.06 [2.92–4.60] vs. 3.43 [IQR, 2.74–4.09], p = 0.011). Patients with a peak-to-peak gradient of ≥10 mm Hg had a significant increase of zlog-NT-proBNP compared with levels from dismission after S1P (median, 1.05 [IQR, 0.80–2.16]; p = 0.002). Particularly noteworthy, this increase in zlog-NT-proBNP levels demonstrated a linear relationship with the peak-to-peak gradient (R ² = 0.537, p < 0.001). Shortly after treatment (median, 3 [1–4] days), there was no longer a significant difference in zlog-NT-proBNP levels between children with and without recoarctation (median 3.78 [3.12–4.58] vs. 3.75 [2.88–4.42]; p = 0.516).

Conclusion: Children with UVHs and recurring coarctation of the aorta demonstrate an increase of zlog-NT-proBNP after S1P, whereby the peak-to-peak gradient correlates linearly with this increase. Regular measurements of zlog-NT-proBNP during the interstage-I period could help identify these patients at an early stage before cardiac decompensation.

Publication History

Article published online:
11 February 2025