Physiologic effects and functional outcome after treatment of dysfunctional right ventricular outflow tract in congenital heart disease using a two-stage intervention

Abstract Background Pathophysiological differences in relief of pulmonary stenosis (PS) as opposed to pulmonary regurgitation (PR) by percutaneous pulmonary valve implantation (PPVI) remain elusive, but might impact current assessment of procedural success and ultimately indications. Methods Invasive pressure measurements, cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed before pre-stenting (BMS), after BMS and after PPVI in patients with either PS or PR. Results In PS ( n  = 14), BMS reduced the right ventricular (RV) to systemic pressure ratio (0.8 ± 0.2 vs. 0.4 ± 0.1%; p p  = .01) but introduced free PR (PR fraction post 39 ± 12%; p p p  = .47). Peak VO2 improved significantly after BMS, with no changes following PPVI (26 ± 9 vs. 30 ± 11 vs. 31 ± 10 ml/kg*min). In PR ( n  = 14), BMS exaggerated PR (PR fraction post 47 ± 10) with reduction in effective RV SV (pre 43 ± 9 vs. post 38 ± 8 ml/m2; p  = .01), which improved after PPVI (post PPVI 49 ± 9 ml/m2; p Conclusions Exercise capacity in patients with right ventricular outflow tract dysfunction is primarily afterload-dependent.