Unprotected left main coronary artery stenting: Are we there yet?

Left main coronary artery (LMCA) disease is found in 3%-5% of patients who undergo cardiac catheterization for chest pain syndrome, congestive heart failure, or cardiogenic shock. Coronary artery bypass grafting has been the standard of care in the management of LMCA disease, with a demonstrated survival rate superior to that achieved with medical therapy. Recent retrospective data suggest an acceptable surgical risk for coronary artery bypass grafting (without concomitant valve surgery) in patients with significant LMCA disease. These data show an in-hospital mortality of 2.3% and an overall 3-year mortality of 15.6%±2.2%. Initial experience with percutaneous coronary intervention (PCI) for LMCA disease, primarily with balloon angioplasty, was disappointing and fraught with a prohibitive procedural and 1-year mortality. The advent of stent use in PCI has introduced another option for these patients. Three recent trials of elective stenting in unprotected LMCA disease in a combined total of 243 patients at low surgical risk and with a normal left ventricular ejection fraction yielded a procedural success rate of 100%, an acute procedural mortality of 0%, a 1-year mortality of 2.0%-2.5%, and a need for subsequent revascularization of 18%-22%. The combined restenosis rate was 20%-23%. In terms of location, the restenosis rate with balloon/stent injury was higher in the distal LMCA and at the bifurcation. In the-low risk elective patient with a normal LMCA and absence of right coronary artery occlusion, it appears that PCI is an acceptable treatment approach. Critical to its success are antiplatelet pre-treatment, optimal technique, and follow-up with repeat angiography. Large, randomized clinical trials are needed to compare PCI with bypass surgery and will provide data for evidence-based management of patients with LMCA disease.