On-line three-dimensional OFDI guided PCI vs. angiography guided in bifurcation lesions: design and rationale of the randomized OPTIMUM trial.

: The aim of this trial is to determine the superiority of on-line three-dimensional optical frequency domain imaging (3D-OFDI) guided percutaneous coronary intervention (PCI) to angiography-guided PCI in bifurcation lesions. The OPTIMUM trial is a randomized, active control, superiority, and multi-center clinical trial. The primary endpoint is the post-procedural percentage of malapposed struts assessed by OFDI in the main branch bifurcation region after final kissing-balloon-dilatation. A total 106 patients will be randomly allocated to either 3D-OFDI or angiography guidance PCI. OPTIMUM trial will be the first prospective, randomised trial and evaluate the efficacy and safety of the on-line 3D-OFDI guided PCI.