Understanding Tetralogy of Fallot Outcomes

Tetralogy of Fallot (ToF) remains the leading cause of cyanotic congenital heart disease worldwide. Surgeons aim for definitive repair, but pulmonary regurgitation (PR) often complicates the postoperative period. Predicting which patients will suffer from significant PR helps in surgical planning. Recent research highlights the utility of the pulmonary valve annulus z-score as a powerful predictive tool.

Predictive Value of Pulmonary Valve Annulus Z-Score

A retrospective study in Indonesia evaluated 101 pediatric patients undergoing ToF repair. The researchers utilized multislice computed tomography (MSCT) to measure preoperative pulmonary valve annulus (PVA) diameters. Furthermore, they assessed early PR using echocardiography within 45 days after the operation. Notably, both the maximal and minimal diameter z-scores showed a strong correlation with moderate or greater PR.

The study identified a critical threshold for clinical decision-making. Specifically, a maximal PVA diameter z-score lower than -2.62 predicted a higher risk of significant early PR. Consequently, clinicians can use this MSCT-derived metric to identify high-risk candidates. Moreover, this standardized approach addresses the variability seen in previous studies regarding optimal cut-off values.

Therefore, integrating MSCT-based measurements into preoperative protocols offers better prognostic clarity. This data allows surgical teams to refine their techniques, such as considering valve-sparing approaches where appropriate. Additionally, these findings provide a localized benchmark for populations with similar demographic profiles.

How does MSCT help in ToF repair planning?

MSCT provides high-resolution, three-dimensional measurements of the minimal and maximal diameters of the valve. This precision allows for accurate z-score calculation, which is more detailed than standard echocardiography in complex cases.

What is the clinical significance of a z-score below -2.62?

A maximal pulmonary valve annulus z-score below -2.62 indicates significant hypoplasia. This finding serves as a strong predictor that the patient may experience moderate or greater pulmonary regurgitation shortly after surgical repair.

Disclaimer: This content is for informational and educational purposes only... Refer to the latest local and national guidelines for clinical practice.

References

Busro PW et al. Preoperative pulmonary valve annulus diameter z score as a predictor of pulmonary regurgitation after tetralogy of Fallot repair: a retrospective cohort study. J Cardiothorac Surg. 2026 Jun 04. doi: 10.1186/s13019-026-04323-2. PMID: 42243828.

Sathanandam S, et al. Management of Tetralogy of Fallot with Pulmonary Atresia. Pediatric Cardiology. 2023.

Predictive Value of Pulmonary Valve Annulus Z-Score for Valve Sparing in Tetralogy of Fallot Repair: A Systematic Review and Meta-Analysis. medRxiv. 2026.