C 2010, Wiley Periodicals, Inc. DOI: 10.1111/j.1540-8183.2010.00562.x Coronary Left Main and Non-Left Main Bifurcation Angles: How are the Angles Modified by Different Bifurcation Stenting Techniques? COSMO GODINO, M.D., 1,2 RASHA AL-LAMEE, M.A., M.R.C.P., 1,2 CLAUDIO LA ROSA, M.D., 1 NUCCIA MORICI, M.D., 4 AZEEM LATIB, M.D., 1,2 ALFONSO IELASI, M.D., 1 CARLO DI MARIO, M.D., 3 GIUSEPPE M. SANGIORGI, M.D., 5 and ANTONIO COLOMBO, M.D. 1,2 1 Interventional Cardiology Unit, San Raffaele Institute, Milan, Italy; 2 EMO-GVM Centro Cuore Columbus, Milan, Italy; 3 Department of Cardiology, Royal Brompton Hospital, London, UK; 4 Unita’ Coronarica, Ospedale Niguarda Ca’ Granda, Milan, Italy; 5 Interventional Cardiology Unit, Policlinico Universitario di Modena, Italy Background: Investigation of the correlation between bifurcation angles and outcomes is limited with discordant results. The aim of this study is to investigate left main (LM) and non-left main (N-LM) bifurcation angles and their modification after percutaneous coronary intervention (PCI). Measurement of all three angles adds to our understanding of bifurcation anatomy and the resultant effect of different stenting techniques. Methods and Results: All three bifurcation angles were described according to the European Bifurcation Club definition: the A (proximal bifurcation angle), the B (distal bifurcation angle) and the C (main branch angle). Measurements were performed in 75 LM and 140 N-LM bifurcations. In LM bifurcations baseline mean values of C, A, and B were 151 ◦ ± 28 ◦ , 131 ◦ ± 32 ◦ , and 78 ± 28 ◦ , respectively. In bifurcations with 2 stents the B significantly decreased by a mean of 10 ◦ (P = 0.003) and A increased by 10 ◦ (P = 0.006). Crush stenting significantly decreased B (A – 14 ◦ ;P = 0.020) and increased A (A + 21 ◦ ;P = 0.005), particularly non-true bifurcations. In N-LM bifurcations mean values for C, A, and B were 156 ◦ ± 19 ◦ , 144 ◦ ± 22 ◦ , and 60 ◦ ± 20 ◦ , respectively. Similar to LM bifurcations, the B became narrower mainly at the expense of the A, which became wider. In both types of bifurcations the greatest variation in A and B was found following 2-stent techniques performed in T-shaped (≥70 ◦ ) bifurcations. Conclusions: In both LM and N-LM bifurcations we found a significant difference in A and B pre- and post-PCI. This difference was driven by the 2-stent technique and was most evident with a baseline bifurcation angle ≥70 ◦ . The Crush technique caused the largest angle variation post-procedure, particularly in non-true LM bifurcations. (J Interven Cardiol 2010;23:382–393) Introduction Coronary bifurcation disease remains one of the most complex coronary lesion subsets, and its treat- ment poses a persistent challenge for the interventional cardiologist. The percutaneous treatment of bifurca- tions is common, accounting for 15–20% of all coro- nary interventions. 1,2 The introduction of drug-eluting stents has resulted in lower event rates and a reduction in main vessel restenosis; however, side-branch os- Address for reprints: Cosmo Godino, M.D., San Raffaele Sci- entific Institute, Via Olgettina 60, 20132 Milan, Italy. Fax: +390226437339; e-mail: cosmogodino@gmail.com tial residual stenosis and long-term restenosis remain a problem. 3 This raises the question as to whether there are mechanistic variables inherent to bifurcations that lead to poor clinical results irrespective of technique. Investigation of the correlation between the bifurcation angle with outcomes immediately after percutaneous coronary intervention (PCI) and at long-term follow- up is limited with discordant results. 4–9 Ormiston et al. 4 and Murasato 10 reported that the degree of the bifurcation angle affected both stent expansion and ap- position to the ostium of the side-branch, thereby em- phasizing the importance of this angle. Unanswered questions remain with regards to a number of issues: (1) whether the degree of the bifurcation affects outcome in 382 Journal of Interventional Cardiology Vol. 23, No. 4, 2010