Infant Transannular Patch Repair of Tetralogy of Fallot Is Associated with Earlier Time to Reintervention

J. Lee¹, K. Gauvreau¹, K. Kohlsaat¹, G. Whitfield¹, A. Muter¹, S. Ghelani¹, D. Hoganson¹, C. Baird², S. Emani³, M. Nathan^1
1Boston Children's Hospital, Boston, Massachusetts ²Boston Children's Hospital, Dept. of Cardiac Surgery, Boston, Massachusetts ³Boston Childrens Hospital, Boston, Massachusetts

Purpose: Prior studies on Tetralogy of Fallot (TOF) with pulmonary stenosis repair types have focused on early outcomes but lack mid/long-term outcomes comparing traditional transannular patch with other repair techniques. We aim to assess associations between TOF repair types and late outcomes, and other potential risk factors linked to worse outcomes.

Methods: This is a single institutional, retrospective cohort study of infants who underwent TOF repair from January 1997 to March 2022. Repair strategies included valve sparing repair (VS), transannular patch (TAP), and TAP with monocusp valve (MC). Unplanned reintervention (RI) post discharge from index complete repair, either surgical or catheterization-based, was categorized as pulmonary valvar (valvar), main pulmonary artery (MPA), branch pulmonary artery (BPA - and includes either right or left pulmonary artery), other RI, and a composite of one or more of these RI (composite). Times from hospital discharge to composite RI and valvar RI by TOF repair subtype were estimated by the Kaplan-Meier method and compared using the log-rank test. Cox regression evaluated these relationships adjusting for known confounders such as age, sex, prematurity, non-cardiac anomalies, and preoperative pulmonary valve Z-score ≤2.5. Separate Cox regression models identified risk factors significantly associated with late RI.

Results: A total of 622 infants underwent TOF repair with a median follow-up of 7.3 (IQR 2.8, 13.6) years, of whom 376 (60%) underwent VS, 231 (37%) TAP and 15 (3%) TAP with MC repair. There were 88 (14%) valvar, 11 (2%) MPA, 58 (9%) BPA, and 50 (8%) other RI. There was no significant difference in time to valvar intervention among the three repair types (p=0.17), but TAP and MC demonstrated a shorter time to composite RI versus VS (p < 0.001). In multivariable analysis, TAP repair subtype (HR: 1.5 [Cl: 1.1, 2.2], p=0.016), but not MC (HR: 2.1 [CI: 0.8, 5.3], p=0.11), was at greater risk of composite RI than VS. Models to assess risk factors found that TAP repair subtype (HR: 1.6 [Cl: 1.2, 2.3], p=0.004), MC repair subtype (HR: 2.7 [CI: 1.0, 6.7], p=0.36), neonatal age (HR: 2.3 [Cl: 1.5, 3.7], p< 0.001), and preoperative LPA or RPA Z-score ≤ -2.5 (HR: 3.8 [Cl: 2.5, 5.6], p< 0.001) were risk factors of composite RI; and neonatal age (HR: 1.9 [Cl: 1.0, 3.3], p=0.039) and preoperative pulmonary valvar Z-score ≤ -2.5 (HR: 2.4 [Cl: 1.6, 3.8], p< 0.001) of late Valvar RI.

Conclusion: Preoperative pulmonary valve Z-score ≤ -2.5 and neonatal repair are independent risk factors for pulmonary valvar and the composite RI. Earlier time to reintervention can be expected with TAP repairs, neonates and patients with preoperative pulmonary valve Z-score ≤ -2.5, warranting closer follow-up and monitoring of residua in these subgroups.

Identify the source of the funding for this research project: Boston Children's Hospital