Neo-Aortic Valve Insufficiency and Root Dilatation During and After the Staged Palliation for Hypoplastic Left Heart Syndrome and Variants

Q: What is the clinical evidence from this study?

Study design: Observational. Population: Hypoplastic Left Heart Syndrome (n=378). Intervention: Norwood procedure vs. No significant neo-aortic valve insufficiency. Primary outcome: 5-year survival rates (HR 7.87, 95% CI 1.66-37.33, p=0.009).

Q: What does this research mean for the field?

Early onset neo-aortic valve insufficiency (Neo-AI) in patients with hypoplastic left heart syndrome is associated with a 7.9-fold increased mortality risk compared to late onset Neo-AI. Novelty: ClaimNovelty.NOVEL_FINDING. Consensus alignment: ConsensusAlignment.CHALLENGES_CONSENSUS.

Muneaki Matsubara; Iulia Telescu; Thibault Schaeffer; Teresa Lemmen; Christoph Röhlig; Jonas Palm; Paul Philipp Heinisch; Nicole Piber; Alfred Hager; Peter Ewert; Jürgen Hörer; Masamichi Ono

doi:10.1007/s00246-026-04205-3

March 14, 2026Pediatric CardiologyOpen Access

Neo-Aortic Valve Insufficiency and Root Dilatation During and After the Staged Palliation for Hypoplastic Left Heart Syndrome and Variants

View Full Paper

Ask AI

Bookmark

Share

Key result

Early onset neo-aortic valve insufficiency linked to ~8-fold greater mortality risk versus late onset.

HR 7.87
95% CI 1.66-37.33
P=0.009
n=378

Why the study?

Neo-aortic valve insufficiency is an emerging complication with long-term survival implications after the Norwood procedure in HLHS and variants, but its clinical impact and development patterns needed investigation.

Does the onset timing of significant neo-aortic valve insufficiency (early vs. late) after the Norwood procedure affect mortality and neo-aortic root dilatation in neonates with HLHS?

Key Points

To assess the clinical impact, survival outcomes, and longitudinal patterns of neo-aortic valve insufficiency and root dilatation in neonates undergoing staged palliation for hypoplastic left heart syndrome and variants.
Retrospective review of 378 neonates undergoing the Norwood procedure between 2001 and 2023 with a median follow-up of 4.3 years.
Serial echocardiograms evaluated neo-aortic valve insufficiency (Neo-AI), classifying cases as early onset (during Norwood hospitalization) or late onset (after discharge).
Neo-aortic root dimensions (sinus of Valsalva and annulus) were measured across four stages of palliation and converted to Z-scores.
Significant Neo-AI developed in 30 patients (7.9%), categorized into early onset (13 patients, 43.3%) and late onset (17 patients, 56.7%).
Early onset Neo-AI was associated with a 7.9-fold increased mortality risk (hazard ratio 7.87, p = 0.009), with 5-year survival of 38.5% compared to 87.8% in late onset cases, and all early deaths occurring within the first year.
Late onset Neo-AI demonstrated progressive sinus of Valsalva dilatation (annual progression rate of 0.33 Z-score units) with significantly larger Z-scores at Fontan completion than early onset patients (5.14 vs. 2.18, p = 0.006).

Study Design

Type

Observational (n=378)

Multicenter

No

Structured PICO

Does the onset timing of significant neo-aortic valve insufficiency (early vs. late) after the Norwood procedure affect mortality and neo-aortic root dilatation in neonates with HLHS?

P

Population

378 neonates with hypoplastic left heart syndrome (HLHS) and variants undergoing the Norwood procedure, median age 8 days, 70.1% male, single-center (Germany).

I

Intervention

Development of significant neo-aortic valve insufficiency (Neo-AI), classified as early onset (during Norwood hospitalization) or late onset (after Norwood discharge).

C

Comparator

Patients without significant neo-AI, and comparison between early onset versus late onset neo-AI.

O

Outcome

Mortality and neo-aortic root dimensions (Z-scores) during staged palliation at median 4.3 years follow-up.hard clinical

Main Result

Effect estimate: HR 7.87 (95% CI 1.66-37.33)

Absolute Event Rate: 38.5% vs 87.8%

p-value: p=0.009

Limitations

Single-center study with limited sample size for neo-AI
Assessment of neo-AI was based on subjective echocardiographic methods
Temporal bias due to long study period
Follow-up duration may be insufficient to capture late complications
Causal relationship between neo-AI and root dilatation could not be established
single-center retrospective analysis with a small number of patients with significant neo-AI limits statistical power
assessment of neo-AI relied on semi-quantitative echocardiographic methods, which are inherently subjective
23-year study period may have introduced temporal bias
follow-up duration (median 4.3 years) may be insufficient to capture the full spectrum of late complications
causal relationship between neo-AI and root dilatation could not be established

Implication

Early onset neo-aortic insufficiency after the Norwood procedure is associated with high perioperative mortality, whereas late onset is associated with progressive root dilatation requiring long-term surveillance.

Abstract

In hypoplastic left heart syndrome (HLHS) and variants, the pulmonary valve functions as the neo-aortic valve after the Norwood procedure. Neo-aortic valve insufficiency (Neo-AI) represents an emerging complication with implications for long-term survival. This study investigated the clinical impact and patterns of Neo-AI development following staged palliation. Neonates undergoing the Norwood procedure (2001–2023) were retrospectively reviewed. Neo-AI was evaluated using serial echocardiograms, with patients classified into two groups: early onset (during the Norwood hospitalization) and late onset (after the Norwood discharge). Neo-aortic root dimensions were measured at four time points during staged palliation, with Z-scores calculated for patient growth. Among 378 patients, significant Neo-AI developed in 30 (7.9%) during median follow-up of 4.3 years. Early onset neo-AI occurred in 13 patients (43.3%) and late onset neo-AI in 17 (56.7%). Cox regression revealed 7.9-fold increased mortality risk in early onset patients (hazard ratios 7.87, p = 0.009), with 5-year survival of 38.5% versus 87.8% in late onset patients. All early onset deaths occurred within the first year. Late onset neo-AI patients demonstrated progressive sinus of Valsalva dilatation (annual progression 0.33 Z-score units). At Fontan completion, late onset neo-AI patients had larger Z-scores than early onset patients [5.14 vs. 2.18, p = 0.006], while surviving early onset patients demonstrated Neo-AI improvement after bidirectional cavopulmonary shunt with subsequent stable root dimensions. Early onset neo-AI associates with acute hemodynamic compromise and higher perioperative mortality. Late onset neo-AI demonstrates progressive root dilatation with superior survival, raising concerns for future valve intervention.

Discussion

No takes yet. Share an insight, caveat, or question.

Cite This Study

Matsubara et al. (2026) conducted an observational in Hypoplastic Left Heart Syndrome (n=378). Norwood procedure vs. No significant neo-aortic valve insufficiency was evaluated on 5-year survival rates (HR 7.87, 95% CI 1.66-37.33, p=0.009). Early onset neo-aortic valve insufficiency was associated with a 7.9-fold increased risk of mortality and a 5-year survival rate of 38.5% compared to 87.8% in late onset patients.

synapsesocial.com/papers/69b79ea18166e15b153ac3c3 https://doi.org/10.1007/s00246-026-04205-3

View Full Paper

Ask AI

Bookmark

Share

Neo-Aortic Valve Insufficiency and Root Dilatation During and After the Staged Palliation for Hypoplastic Left Heart Syndrome and Variants

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

Neo-Aortic Valve Insufficiency and Root Dilatation During and After the Staged Palliation for Hypoplastic Left Heart Syndrome and Variants

Key Points

Study Design

Structured PICO

Main Result

Limitations

Implication

Abstract

Discussion

Cite This Study

Keep reading

Keep reading