Factors associated with the need for pulmonary valve replacement in asymptomatic patients with isolated pulmonary regurgitation after repair of tetralogy of Fallot: a cardiac magnetic resonance study.

Background: Pulmonary regurgitation (PR) is the most common late complication in patients after repair of tetralogy of Fallot (TOF). Most patients remain asymptomatic over years, but eventually, the compensatory mechanisms fail, leading to right ventricular (RV) dilation and dysfunction, limited exercise capacity, ventricular arrhythmia, and sudden death.

Aims: We aimed to evaluate associations between cardiac magnetic resonance (CMR) parameters and the need for either surgical or percutaneous pulmonary valve replacement (PVR) in asymptomatic patients with significant PR after repair of TOF.

Methods: Of 209 patients with repaired TOF who had undergone a CMR study, we selected 61 asymptomatic patients with moderate‑to‑severe PR and followed them for up to 4 years (mean [SD], 21.4 [13.7] months). We excluded patients with residual ventricular septal defect, a peak RV outflow tract gradient of 30 mm Hg or higher, or at least moderate tricuspid regurgitation.

Results: Receiver operating characteristic curve analyses revealed that the ratio of RV to left ventricular (LV) volume (RV/ LV ratio; threshold >2.4) and PR fraction (PRF; threshold >33%) had acceptable discriminatory capacity to differentiate between patients requiring PVR and those treated conservatively. The Cox proportional hazards regression and the Kaplan–Meier curves revealed that the RV / LV ratio and PRF was significantly associated with the need for PVR. The combination of the RV / LV ratio and PRF provided significant discrimination in terms of survival without PVR (P <0.001; log‑rank test for trend).

Conclusions: The RV/ LV ratio and PRF were significantly associated with the need for PVR in asymptomatic patients with isolated moderate‑to‑severe PR after repair of TOF.