Effect of Tadalafil on Heart Function in Children with Severe Pulmonary Regurgitation Following Surgical Repair of Tetralogy of Fallot: A Prospective Study

Tetralogy of Fallot (TOF) is the most prevalent cyanotic congenital heart defect. Pulmonary regurgitation (PR) is a common sequela following most surgical repairs for TOF. Tadalafil might reduce pulmonary vascular resistance after Tetralogy of Fallot total correction (TOFTC).

This study evaluated the efficacy of tadalafil in reducing PR volume and improving heart function among TOFTC children with severe PR, using transthoracic echocardiography, particularly focusing on changes in N-terminal pro-b-type natriuretic peptide (NT-proBNP).

The present study was conducted on TOFTC patients consecutively between September 2019 and August 2020 at Shiraz University of Medical Sciences, Shiraz, Iran. M-mode and two-dimensional (2D) Doppler echocardiography were performed, and NT-proBNP levels were measured in 20 patients before and one month after tadalafil administration. SPSS version 23.0 was utilized to analyze all results.

The patients' ages ranged from 25 to 128 months. The mean age and weight of the patients were 67.9 ± 34.5 months and 21.1 ± 6.9 kg, respectively. Tadalafil administration did not significantly improve Doppler and tissue Doppler parameters; however, it increased the pulmonary valve pressure gradient and velocity-time integral. Additionally, tadalafil had no significant effect on improving NT-proBNP levels. The Spearman correlation test did not show any significant correlation between the pulmonary valve pressure gradient and velocity-time integral with age, weight, and NT-proBNP.

Tadalafil increased the pulmonary valve pressure gradient and velocity-time integral in TOFTC patients with severe PR; however, it did not affect NT-proBNP levels or tissue Doppler parameters.