Morphological and hemodynamic effectiveness of stenting for pulmonary artery stenosis -subanalysis of JPIC stent survey

Background: Percutaneous stenting for branch pulmonary artery stenosis is an established interventional choice in congenital heart disease. The apparent morphologic change in the vessel diameter often differs from the hemodynamic result. Methods and Results: We performed a subanalysis of the data from the Japanese Society of Pediatric Interventional Cardiology (JPIC) stent survey. The factors that may have contributed to morphologic effectiveness included reference vessel diameter (RVD), minimum lumen diameter (MLD) and percent diameter stenosis (%DS) and the relation between morphologic and hemodynamic effectiveness was evaluated in 206 lesions treated with stenting. We defined a “50% increase in MLD” as “morphologically effective”, while “achievement of either a reduced pressure gradient greater than 50% or an increase of perfusion ratio to the affected side to the contralateral side greater than 20%” as “hemodynamically effective”. Morphologic effectiveness was achieved in 84% of patients. Before stenting, %DS was significantly larger, while RVD was smaller in the “effective” group than in the “non-effective” group. The cutoff value for effective stenting was 51% for %DS and 14.7 mm for RVD before stenting. Hemodynamic effectiveness was obtained more often in the “morphologic effective” group. Conclusions: RVD and %DS were the 2 main contributors to acute morphologic effectiveness. There was a significant relationship between “morphologic effectiveness” and “hemodynamic effectiveness”, judging from increased perfusion of the affected lung and/or decreased pressure gradient.