a foreign object in the body, and placement of a stent will inevitably lead to damage of a blood vessel's lining (endothelium). Drug-eluting stents, by their nature, prevents the formation of a new endothelial layer. Endothelialization is a hallmark of vascular healing and is important for the prevention of thrombus formation. Without proper healing, the risk of clot formation persists for a much longer period of time. For drug-eluting stents, the time course of complete healing in humans is unknown. Thus, clotting suppressant agents are routinely given during placement, and anti-clotting agents are continued well after implantation. In-stent restenosis (ISR) As stated earlier, DES were designed to specifically combat issues of restenosis that occurred with BMS. Though less frequent with drug-eluting stents, restenosis still occurs with DES. The process of restenosis is attributable to a phenomenon known as neointimal hyperplasia. In brief, the process begins with damage to the arterial wall, which can occur in the form of stretch injury during stent positioning or mechanical injury (tearing of vessel lining) during stent deployment. Following injury, platelets, smooth muscle cells, and inflammatory cells (macrophages) will gather at the damaged site and begin the repair process. This can involve the deposition of collagen, proliferation of smooth muscle, and creation of a new vessel lining. However, this process can lead to thickening of the arterial walls and decreased lumen space, resulting in stenosis. Since the advent of DES technology, the incidence of ISR has significantly decreased. While rates of ISR ranged from 20-35% with BMS, DES has reduced the incidence to about 5-10%. This improvement has resulted in the near-elimination of BMS from clinical use; however, research efforts continue on newer-generation sirolimus-based stents, as well as pioneering image-guided stent placement procedures. Alternatives to stents Pharmacological therapy for coronary artery disease may be indicated instead of or in addition to invasive treatment. For those requiring percutaneous coronary intervention or surgery, medical therapy should be viewed as complementary to revascularization procedures, rather than an opposing strategy. Coronary artery bypass graft surgery is the best treatment for some patients. Differences between outcomes with stenting and with coronary artery bypass surgery (CABG) are a point of controversy. A recent study comparing the outcomes of all patients in New York state treated with CABG or percutaneous coronary intervention (PCI) demonstrated CABG was superior to PCI with DES in multiple-vessel coronary artery disease . Patients treated with CABG had