Impact of right ventricular outflow tract size and substrate on outcomes of percutaneous pulmonary valve implantation

Abstract

Owing to the wide variety of surgical substrates used for right ventricular outflow tract (RVOT) reconstruction, the predictors of successful outcomes in such patients are unclear. To compare haemodynamic outcomes of percutaneous pulmonary valve implantation (PPVI) in patients with dysfunctional RVOT. This was a multicentre prospective study on all consecutive patients who underwent PPVI from May 2008 to December 2009. All patients underwent prestenting using a bare-metal stent. The patients were divided into two groups based on the surgical substrate used for RVOT reconstruction. Baseline demographics, including right ventricle to pulmonary artery (RV-PA) pressure gradient and RV/aortic (Ao) pressure ratio, were similar in both groups. The mean RV-PA gradient and RV/Ao pressure ratio showed immediate and significant improvement after PPVI. At last follow-up, the RV-PA gradient and RV/Ao pressure ratio were significantly higher in patients with non-expandable conduits (P=0.002 and P=0.008, respectively). Patients with conduits greater than 20 mm showed better immediate and midterm outcomes compared with other patients. Patients with non-expandable conduits less or equal to 20 mm diameter showed good immediate outcomes but poor midterm haemodynamic outcomes compared with those with expandable conduits less or equal to 20 mm diameter (P=0.03). PPVI is successful with a wide variety of surgical substrates used for RVOT reconstruction; there was immediate haemodynamic improvement in all patients. However, patients with non-expandable conduits less or equal to 20 mm had the worst outcomes. This information should be integrated into the decision-making process before selecting patients for PPVI.