Multicenter Prospective Randomized Study of First-choice Guidewires in Percutaneous Coronary Intervention for Chronic Total Occlusion

Background. Although the success rate of PCI for CTO is yet to reach a satisfactory level, prognoses have been improved in successful cases. The greatest challenge is the passage of the guidewire and a variety of new approaches including a parallel wire technique and a retrograde approach have been reported. However, the fundamental question of what type of guidewire is the most appropriate as a first-choice guidewire has not been answered.Tapered guidewires have recently been reported to be useful for CTO lesions. In addition, a multicenter prospective registry indicates the effectiveness of 0.010-inch guidewires (PIKACHU registry, personal communication). Its mechanism is associated with micro-channels ranging from 100 to 300 μm in size in CTO lesions. If 250 μm micro-channels are present in 60% of CTO lesions, a 0.010-inch (equivalent to 250 μm) guidewire theoretically can pass through the lesion at the probability of 60%, and this assumption consists with the findings of the PIKACHU study. This idea also suggests that a 0.014-inch (350 μm) guidewire is unlikely to pass through lesions.

Based on the above, a hypothesis has been formulated that a guidewire with a small tip should be selected as a first-choice guidewire for CTO lesions. In this study, patients will be prospectively randomized to slender guidewires or standard 0.014-inch guidewires to determine appropriate first-choice guidewires.

Objective. To determine appropriate first-choice guidewires.

Design. Prospective multicenter randomized controlled trial

Methods. The first choice guidewire to treat CTO lesion was randomly assigned to normal group (distal tip size 0.014 inch) or slender group (distal tip size 0.010 inch or less). The primary passage must be performed with antegrade approach.