Bifurcation lesions remain a challenging topic in interventional cardiology, with multiple approaches and strategies for intervention. Bifurcation lesions account for 15% to 20% of coronary stenoses and significantly increase the complexity of intervention exponentially. The 2011 American College of Cardiology (ACC) guidelines recommend provisional side branch stenting as the initial strategy when the side branch is not large and has mild to moderate disease. If the side branch is large with a high risk of occlusion and a low likelihood of side branch reaccess, then a planned 2-stent strategy is reasonable.
The European Bifurcation Club (EBC) defines a bifurcation lesion as: “A coronary artery narrowing occurring adjacent to, and/or involving the origin of a significant side branch.”1 This definition is to be used practically, with a significant side branch being one that could incur a significant chance of myocardial injury if occluded during intervention. At least 6 different classifications exist for bifurcation lesions, but the most widely accepted is the Medina classification2 (Figure 15-1).
The Medina classification scores each stenosis in a binary system, with >50% stenosis scored as 1 and <50% stenosis scored as 0. The numbering convention goes in order, separated by commas—proximal main vessel, distal vessel, side branch—with resulting scores as shown. MB, main branch; SB, side branch. (Used with permission, from Medina A, Suárez de Lezo J, Pan M. A new classification of coronary bifurcation lesions. Rev Esp Cardiol. 2006;59(2):183.)
The Medina classification scores the 3 arterial segments of a bifurcation sequentially with a binary 0 or 1, based on the absence or presence of a stenosis greater than 50% of the vessel diameter. The segments assessed are, in order, the proximal main vessel, the distal main branch, and the side branch. For example, a stenosis involving only the proximal main vessel and the side branch ostium would be coded as 1,0,1.
The Medina classification has prevailed due to its simplicity and ease of use, but it eschews numerous other factors, including branch size, lesion length, takeoff angle, disease severity, location at the ostium, degree of calcification, and other anatomic considerations. The challenges of bifurcation percutaneous coronary intervention (PCI) are derived primarily from the sum of these anatomic considerations and may direct the strategy for intervention. Furthermore, such anatomic and technical factors may impact long-term clinical outcomes3 (Figure 15-2).
A myriad of factors distinguish one bifurcation lesion from another, including the distribution of atherosclerotic disease, branch angles, tapering of vessels from ostium to distal vessel, eccentricity of plaque, distance from the bifurcation, and other factors. MV, main vessel; SB, side branch. (Used with permission, from Sgueglia GA, Chevalier B. Kissing balloon inflation in percutaneous coronary interventions. JACC Cardiovasc Interv. 2012;5(8):803-811.)