Effect of Infundibular Stenosis on Growth of the Pulmonary Valve Annulus in Patients With Tetralogy of Fallot

Abstract

Objective: This study aimed to determine the effect of the degree of infundibular stenosis on growth of the pulmonary valve (PV) annulus in patients with tetralogy of Fallot (ToF). Methods: We reviewed clinical data of all patients who underwent ToF repair between 2002 and 2022. The diameter of the infundibular area was measured before ToF repair using a lateral view of angiography at end-systole and divided by the body surface area (infundibular index [mm/m²]). The cohort was divided into two groups, a systemic-to-pulmonary artery shunt (SPS) and a primary intracardiac repair (ICR), and compared for pulmonary annular growth and the infundibular index. Results: A total of 119 patients were included; the SPS group (n = 54) and the primary ICR group (n = 65). At ToF repair, the PV annulus was preserved in 43/65 patients (66%) in the primary ICR group and 23/54 (43%) in the SPS group (P = .0098). In a linear regression analysis, the infundibular index was significantly associated with PV growth (P < .001). The growth of the PV annulus was significantly associated with the infundibular index in both groups. In the 60 patients with a small PV annulus (Z-score < −2.0) at the initial presentation, logistic regression analysis showed that the infundibular index was the only factor significantly associated with PV preservation at ToF repair (P = .005). Conclusion: The degree of infundibular stenosis has a significantly greater effect on pulmonary annular growth than the presence of an SPS, which may affect the preservation of the PV at the time of ToF repair.