Percutaneous Coronary Intervention for Left Main Coronary Artery Disease: Is it Time to Change the Guidelines?

Abstract

Significant left main coronary artery (LMCA) disease (i.e., stenosis, ≥50% of lumen) is the most lethal form of coronary artery disease. It is present in 3%‐5% of patients undergoing coronary angiography. 1 Those who require medical treatment have a poor prognosis, and there is a 3-year mortality rate of 50%. 1 On the other hand, randomized trials carried out at the end of the 1970s demonstrated that survival is significantly improved by revascularization surgery. 2 The favorable outcome of revascularization surgery and the poor results that were initially obtained with percutaneous coronary intervention (PCI), which was associated with elevated short-term and long-term mortality rates (e.g., a 3-year survival rate of 36%), 3 made surgery the treatment of choice for the majority of patients. This is reflected in current clinical guidelines. 4 For example, the guidelines of the Spanish Society of Cardiology (Sociedad Espanola de Cardiologia) classify PCI for LCA disease as a class-IIb indication. 5 Nevertheless, it is necessary to distinguish between two distinct morphological states in LMCA disease: that in which the LMCA is protected by a patent arterial or venous bypass graft that perfuses the left coronary area, and that in which the LMCA is unprotected. In addition, there are also two different clinical circumstances with distinct levels of risk: when the LMCA intervention is elective, and when treatment must be implemented urgently because of acute myocardial infarction (AMI) or because there is either an acute spontaneous occlusion or iatrogenic occlusion resulting from catheter manipulation.