Stenting or bypass surgery for unprotected left main coronary artery disease—still a long rally to go

Coronary artery disease (CAD) is still major cause of mortality and morbidity in western country (1,2). With the advancement of percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG) is not the only choice of revascularization for CAD (1,2). The left main coronary artery (LMCA) arises from aortic sinus and supplies the around 70% myocardium in patients with right dominant type and 100% in patients with left dominant type (3). Therefore, severe LMCA stenosis will reduce coronary perfusion to large portion of the myocardium and may cause terrible consequences. The definition of LMCA stenosis is the reduction by more than 50% in the luminal diameter of LMCA (4).