Japan and the US have seen an increase in percutaneous coronary intervention (PCI) procedures, which is driven primarily by a rise in elective PCIs in Japan compared to non-elective in the U.S., according to a study in the Journal of the American College of Cardiology. Since adoption of large-scale PCI trial results vary internationally, the study sought to analyze large national registries in both countries to illuminate international variation in PCI practice as a foundation for further quality improvement.