EFFICACY OF CORONARY STENTING VERSUS BALLOON ANGIOPLASTY IN SMALL COROLLARY ARTERIES

Objectives. The goal of this study was to compare the efficacy of elec tive stent implantation and balloon angioplasty for new lesions in sma ll coronary arteries. Background. Palmaz-Schatz stents have been desig ned and approved by the Food and Drug Administration for use in corona ry arteries with diameters greater than or equal to 3.0 mm. The effica cy of elective stent placement in smaller vessels has not been determi ned. Methods. By quantitative coronary angiography, 331 patients in th e Stent Restenosis Study (STRESS) I-II were determined to have a refer ence vessel <3.0 mm in diameter, Of these, 163 patients were randomly assigned to stenting (mean diameter 2.69 +/- 0.21 mm), and 168 patient s were assigned to angioplasty (mean diameter 2.64 +/- 0.24 mm). The p rimary end point was restenosis, defined as greater than or equal to 5 0% diameter stenosis at 6-month follow up angiography. Clinical event rates at 1 year were assessed, Results. Baseline clinical and angiogra phic characteristics were similar in the two groups, Procedural succes s was achieved in 100% of patients assigned to stenting and in 92% of patients assigned to angioplasty (p < 0.001). Abrupt closure within 30 days occurred in 3.6% of patients in both groups. Compared with angio plasty, stenting conferred a significantly larger postprocedural lumen diameter (2.26 vs. 1.80 mm, p < 0.001) and a larger lumen at 6 months (1.54 vs, 1.27 mm, p < 0.001). Restenosis (greater than or equal to 5 0% diameter stenosis at follow-up) occurred in 34% of patients assigne d to stenting and in 55% of patients assigned to angioplasty (p < 0.00 1). At 1 year, event-free survival was achieved in 78% of the stent gr oup and in 67% of the angioplasty group (p = 0.019). Conclusions. Thes e findings suggest that elective stent placement provides superior ang iographic and clinical outcomes than balloon angioplasty in vessels sl ightly smaller than 3 mm. (C) 1998 by the American College of Cardiolo gy.