A coronary stent is a hollow, artificial device of small diameter, which may be used to expand a coronary artery that has become obstructed for various reasons. The type currently in use locally is made of stainless steel mesh, which is inserted in the artery, surrounding a balloon. On arrival at the desired location, the balloon is inflated, expanding the stent, and securing it to the wall of the artery. This restores the blood flow in the area of the procedure. Stents can be used as an alternative to balloon angioplasty, and ideally, may lessen the need for cardiac surgery.
Three articles in the 23 December issue of the New England Journal of Medicine report on the use of stents. One article outlines the results of an analysis made by a group from Vancouver General Hospital, of data on all percutaneous (performed through the skin) coronary interventions in British Columbia between April 1994 and June 1997. Some 9600 procedures were analyzed. During the period, a large increase in the rate of stenting was associated with a significant reduction in the rate of "adverse cardiac events." This was felt to be exclusively due to a large reduction in follow-up revascularization [further action to restore an adequate blood supply], without significant changes in heart attacks or death. It was held that this reduction was at least coincident with the introduction and subsequent widespread use of coronary stenting.
In an international study headed by Dr. Cindy Grimes of the William Beaumont Hospital in Royal Oak, Michigan, patients with acute myocardial infarction, who were to undergo emergency catheterization and angioplasty, and who were judged to be suitable stenting risks, were randomly assigned to undergo angioplasty with stenting (452 patients) or balloon angioplasty alone (448 patients). After six months, fewer patients in the stent group than in the angioplasty group had angina or needed revascularization. In addition, death, disabling stroke, or reinfarction occurred in fewer patients in the stent group. It was felt that the latter result was due entirely to the decreased need for revascularization. The group's conclusion was that "in patients with acute myocardial infarction, routine implantation with a stent has clinical benefits beyond those of primary coronary angioplasty alone."