Treatment of Unprotected Left Main Coronary Artery Stenosis in the Drug‐Eluting Stent Era

Coronary angiography is often inadequate for estimating the severity of ambiguous left main coronary artery (LMCA) stenoses. Our assessment of these lesions can be improved by the techniques of intravascular ultrasound and fractional flow reserve which provide indices of stenosis severity to enable the prediction of future events and planning of treatment. For patients requiring LMCA revascularization, coronary artery bypass graft (CABG) surgery has been gold standard for decades. However, this technique continues to be limited by factors such as periprocedural mortality, prolonged hospital stay and rehabilitation, and long-term graft patency. LMCA stenosis remains one of the few serious challenges for the interventional cardiologists and, in the bare metal stent era, the long-term results were not sufficient to replace CABG surgery, mainly because of the high restenosis rate. Drug-eluting stents (DES) have dramatically reduced the restenosis rate and early results in small series (approximately 300 patients in total) treated with DES in LMCA have been encouraging, especially for lesions at the ostium and in the left main shaft. Before changes are made in the guidelines for treatment, we must wait for a refinement in the technique and stent design used for bifurcational left main lesion and the results of randomized, specific multicenter studies (SYNTAX trial). It is likely that, for selected patients, LMCA stenosis will be regarded as an indication for PCI.