Impact of calcified bifurcation lesions in patients undergoing percutaneous coronary intervention using drug-eluting stents: results from the COronary BIfurcation Stent (COBIS) II registry

Min Chul Kim1, MD; Youngkeun Ahn1*, MD, PhD; Doo Sun Sim1, MD, PhD; Young Joon Hong1, MD, PhD; Ju Han Kim1, MD, PhD; Myung Ho Jeong1, MD, PhD; Hyeon-Cheol Gwon2, MD, PhD; Hyo-Soo Kim3, MD, PhD; Seung Woon Rha4, MD, PhD; Jung Han Yoon5, MD, PhD; Yangsoo Jang6, MD, PhD; Seung-Jea Tahk7, MD, PhD; Ki Bae Seung8, MD, PhD