Efficient distal tip size of primary guidewire for antegrade percutaneous coronary intervention in chronic total occlusion: The G-FORCE study Yuji Ikari a, ⁎, Masaki Awata b , Kazuaki Mitsudo c , Takashi Akasaka d , Shigeru Saito e , Takayuki Ishihara b , Toshiharu Fujii a , Hideki Hashimoto f , Mitsuyasu Terashima g , Tomokazu Ikemoto h , Kiyoshi Hibi i , Junichi Tazaki j , Akihiro Nakamura k , Hideo Nishikawa l , Tadaya Sato m , Yoshihisa Nakagawa n a Tokai University School of Medicine, Isehara, Japan b Kansai Rosai Hospital, Amagasaki, Japan c Kurashiki Central Hospital, Kurashiki, Japan d Wakayama Medical University, Wakayama, Japan e Shonan Kamakura General Hospital, Kamakura, Japan f University of Tokyo, Tokyo, Japan g Toyohashi Heart Center, Toyohashi, Japan h Jichi Medical University, Shimotsuke, Japan i Yokohama City University Medical Center, Yokohama, Japan j Graduate School of Medicine, Kyoto University, Kyoto, Japan k Iwate Prefectual Central Hospital, Morioka, Japan l Mie Heart Center, Mie, Japan m Akita Medical Center, Akita, Japan n Tenri Hospital, Tenri, Japan abstract article info Article history: Received 21 July 2016 Accepted 5 November 2016 Available online 9 November 2016 Background: Although several new techniques have been introduced for CTO such as the retrograde approach, the fundamental question of what type of guidewire is the most appropriate as a primary guidewire in the antegrade approach has not been answered. Methods: The G-FORCE study was designed as a prospective multicenter randomized controlled trial to determine the efficient primary guidewire in antegrade approach for chronic total occlusion (CTO). The first guidewire was randomly assigned to a regular size distal tip group (0.014 in. size) or tapered tip group (0.010 in. or less). The primary endpoint was defined as successful lesion penetration by the first guidewire into distal true lumen. This study was registered at ClinicalTrials.gov with identifier NCT00987610. Results: A total of 260 patients were enrolled, with an average age of 66 ± 11 years and 16%were female. The average J-CTO score was 1.8 ± 1.1. The primary endpoint was achieved in 38% and 32% of patients using tapered and regular distal tip guidewires, respectively (P = 0.80). The final PCI success rate was 81% vs. 85%, respectively (P = 0.57). Easy CTO lesions with a J-CTO score = 0 exhibited a primary endpoint significantly different between tapered and regular distal tip primary guidewires (79% vs. 40%; P = 0.046). Guidewire distal coating or distal tip load did not relate with primary guidewire success rate. Conclusion: Tapered and regular distal tip guidewires are equivalent as a first choice for CTO. Tapered guidewires are superior for CTO lesions with a J-CTO score = 0. © 2016 Elsevier Ireland Ltd. All rights reserved. Keywords: Coronary artery disease Clinical trials Percutaneous coronary intervention Chronic total occlusion 1. Introduction Although percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) is technically challenging, prognoses and left ventricu- lar function have improved in successful cases [1] and long-term results enhanced with the use of second generation drug-eluting stents [2].A great challenge is the passage of the guidewire [3] even with a variety of new methods, including new types of guidewires, a parallel wire technique and a retrograde approach. However, the fundamental ques- tion of what type of guidewire is the most appropriate as a primary guidewire has not been answered. Tapered guidewires and 0.010 in., slender guidewires have recently been reported to be useful for CTO le- sions [4,5]. A small distal tip may also be advantageous for microchannel tracking inside a CTO lesion. In this study, patients were prospectively randomized into groups using either tapered (0.010 in. or less) or International Journal of Cardiology 227 (2017) 94–99 ⁎ Corresponding author at: Department of Cardiology, Tokai University, School of Medicine, 143 Shimokasuya, Isehara 259-1193, Japan. E-mail address: ikari@is.icc.u-tokai.ac.jp (Y. Ikari). http://dx.doi.org/10.1016/j.ijcard.2016.11.076 0167-5273/© 2016 Elsevier Ireland Ltd. All rights reserved. Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard