Unprotected left main coronary stenting as alternative therapy to coronary bypass surgery in high surgical risk acute coronary syndrome patients.

Acute coronary syndrome has a high mortality rate that dramatically increases in the presence of left main coronary artery (LMCA) disease. Over the past decades, coronary artery bypass graft (CABG) surgery has been commonly accepted as the standard of care for patients with LMCA stenosis and is still considered the first-line treatment in current practice guidelines. Percutaneous coronary intervention (PCI) of protected and unprotected LMCA has gained popularity and is increasingly utilized with comparable outcomes to CABG in randomized controlled trials. In-stent restenosis and the need for revascularization provide the main obstacle to LMCA revascularization. The advent of better PCI equipment, stents, ablative devices, intravascular ultrasound, hemodynamic support devices and antithrombotic agents have ignited a renewed interest in the practice of LMCA PCI, especially for high surgical risk patients who are neither candidates nor agreeable to CABG surgery. Herein, we review the studies comparing unprotected LMCA stenting with CABG surgery in regard to 3 main endpoints: mortality, major adverse events and the incidence of repeat revascularization.