Clinical and CMR-Based Predictors for the Need of Pulmonary Valve Replacement in Patients after Repair of the Tetralogy of Fallot—Data from the German Competence Network

Objective and Background: Although pulmonary valve replacement (PVR) effectively reduces right ventricular (RV) volume and pressure overload in patients after repair of the tetralogy of Fallot (TOF), uncertainties still remain regarding indications and timing of PVR. The aim of our study was to identify factors that were predictive for the need of PVR during follow-up in a larger cohort of TOF patients. Furthermore, the potential beneficial impact of a mild residual right ventricular outflow tract (RVOT) gradient should be investigated.

Methods: In a prospective multicenter study, 292 TOF patients (mean age: 17.6 ± 7.8 years) were included that underwent a cardiovascular magnetic resonance (CMR), CPET, and echocardiographic study. Need of PVR during follow-up was assessed. To study the impact of a mild RVOT obstruction (15–30 mm Hg peak systolic gradient) on the need of PVR, this subgroup of patients was compared with those with no relevant gradient (<15 mm Hg) and a group of patients with a RVOT gradient >30 mm Hg. The groups were further separated according to severity of pulmonary regurgitation (PR) quantified by CMR in PR <25% and PR ≥25%. Patients were also stratified according timing of PVR.

Result: PVR was performed in 119 of the 292 patients (41%) at a median of 3.0 (0.0–12.3) years after the CMR study. On univariate Cox's regression analysis, the following factors were significant predictors for the need of PVR: initial palliation (HR = 1.58, 95% CI: 1.03–2.43, p = 0.04), NYHA functional class >I (HR = 1.74, 95% CI: 1.20–2.51, p < 0.01), QRS duration (HR = 1.01, 95% CI: 1.01, p = 0.01), RV end-diastolic volume (HR = 1.01, 95% CI: 1.00–1.03, p < 0.01), RV mass (HR = 1.02, 95% CI: 1.01–1.04, p < 0.01), PR (HR = 1.03, 95% CI: 1.03–1.05, p < 0.01), as well as lower RVEF (HR = 0.96, 95% CI: 0.95–0.98, p < 0.01), and LVEF (HR = 0.98, 95% CI: 0.96–1.00, p = 0.02). A higher RVOT gradient was also a risk factor for PVR (HR = 1.02, 95% CI: 1.01–1.03, p < 0.01). In patients with ≥25%, the need for PVR was similar between the different RVOT-stenosis subgroups (p = 0.31 and 0.37). Patients with <25% PR and a RVOT gradient of <15 mm Hg had the lowest risk for PVR.

Conclusion: A high proportion of repaired TOF patients underwent PVR after the initial CMR study. Among several clinical factors and CMR parameters, RV pressure load was a significant predictor for the need of PVR. In patients with relevant PR, a mild residual RVOT gradient did not protect from PVR.

Publikationsverlauf

Artikel online veröffentlicht:
21. Februar 2021