Differences in routes of guiding catheters for left coronary artery according to access sites assessed by the combined angiography-computed tomography system.

Differences in guiding catheters (GCs) manipulations and selections among different access sites are currently unclear. We examined the differences in the routes of GCs for the left coronary artery (LCA) among the right radial, left radial, and femoral approaches. We used a combined angiography-computed tomography (CT) system that enabled to perform CT scans during percutaneous coronary intervention (PCI). We enrolled 88 patients who underwent CT scans during LCA PCI or percutaneous transluminal septal myocardial ablation. To evaluate the route of GCs, we analyzed the positions of the catheter's contact point on the contralateral aortic wall to the LCA ostium, which were expressed by the angle formed by the vertical line and the diagonal line from the GC shaft to the center of the aorta. The procedures were performed via the right radial in 47 cases, left radial in 20, and femoral approach in 21. The positions of the catheter's contact point were significantly different depending on the approaches (interquartile range - 3.7 [- 14.3 to 7.8], - 46.5 [- 76.9 to - 9.3], and - 30.7 [- 39.4 to - 22.4] degrees, respectively; p < 0.001). Multivariate analysis demonstrated that access sites and LCA ostium locations had significant impacts on the positions of the catheter's contact point. The routes of LCA GCs were different among the right radial, left radial, and femoral approaches.