A COMPARISON OF BALLOON-EXPANDABLE-STENT IMPLANTATION WITH BALLOON ANGIOPLASTY IN PATIENTS WITH CORONARY-ARTERY DISEASE

Background. Balloon-expandable coronary-artery stents were developed t o prevent coronary restenosis after coronary angioplasty. These device s hold coronary vessels open at sites that have been dilated. However, it is unknown whether stenting improves longterm angiographic and cli nical outcomes as compared with standard balloon angioplasty. Methods. A total of 520 patients with stable angina and a single coronary-arte ry lesion were randomly assigned to either stent implantation (262 pat ients) or standard balloon angioplasty (258 patients). The primary cli nical end points were death, the occurrence of a cerebrovascular accid ent, myocardial infarction, the need for coronary-artery bypass surger y, or a second percutaneous intervention involving the previously trea ted lesion, either at the time of the initial procedure or during the subsequent seven months. The primary angiographic end point was the mi nimal luminal diameter at follow-up, as determined by quantitative cor onary angiography. Results. After exclusions, 52 patients in the stent group (20 percent) and 76 patients in the angioplasty group (30 perce nt) reached a primary clinical end point (relative risk, 0.68; 95 perc ent confidence interval, 0.50 to 0.92; P = 0.02). The difference in cl inical-event rates was explained mainly by a reduced need for a second coronary angioplasty in the stent group (relative risk, 0.58; 95 perc ent confidence interval, 0.40 to 0.85; P = 0.005). The mean (+/-SD) mi nimal luminal diameters immediately after the procedure were 2.48+/-0. 39 mm in the stent group and 2.05+/-0.33 mm in the angioplasty group; at follow-up, the diameters were 1.82+/-0.64 mm in the stent group and 1.73+/-0.55 mm in the angioplasty group (P = 0.09), which correspond to rates of restenosis (diameter of stenosis, greater than or equal to 50 percent) of 22 and 32 percent, respectively (P = 0.02). Peripheral vascular complications necessitating surgery, blood transfusion, or b oth were more frequent after stenting than after balloon angioplasty ( 13.5 vs. 3.1 percent, P<0.001). The mean hospital stay was significant ly longer in the stent group than in the angioplasty group (8.5 vs. 3. 1 days, P<0.001). Conclusions. Over seven months of follow-up, the cli nical and angiographic outcomes were better in patients who received a stent than in those who received standard coronary angioplasty. Howev er, this benefit was achieved at the cost of a significantly higher ri sk of vascular complications at the access site and a longer hospital stay.