Randomized Trial of Pulmonary Valve Replacement in Tetralogy of Fallot

Background:

Surgical repair of TOF often results in chronic pulmonary regurgitation (PR) with associated RV dilatation and dysfunction. Mounting evidence indicates that PR leads to significant long-term morbidity and mortality, including arrhythmias, sudden death, and right heart failure. Using CMR, there is a high prevalence of regional dysfunction and aneurysms in the RV in patients with repaired TOF. Current standard clinical practice in patients with repaired TOF, severe PR, ventricular dysfunction, and/or clinical deterioration is to insert a bioprosthetic pulmonary valve to reduce the volume load on the RV. Although PVR can be achieved with low mortality, research has shown a persistent or worsening RV dysfunction postoperatively, despite a competent pulmonary valve. In patients with left ventricular (LV) aneurysms, surgical remodeling with aneurysm resection has been shown to improve LV mechanics. In view of the potentially deleterious effects of aneurysmal and akinetic wall segments on RV mechanics, researcher have recently modified their PVR surgical technique in selected patients to include surgical remodeling of the RV with resection of the akinetic wall segments. However, no studies have systematically compared the efficacy of PVR plus surgical RV remodeling to PVR alone.

Research Question:

Is there a difference between two surgical strategies-PVR alone (bioprosthetic pulmonary valve insertion and, when present, resection of right ventricular outflow tract [RVOT] aneurysm) versus PVR and surgical RV remodeling (bioprosthetic pulmonary valve insertion and resection of akinetic scarred areas on the anterior RV wall to reduce RV volume)-on RV mechanics and on the incidence of adverse events in patients with repaired TOF and chronic pulmonary regurgitation?