Two hundred AVE (Arterial Vascular Engineering) microstents measuring 4 to 30 mm were implanted in 140 patients aged 62 +/- 10 years with Class II to IV angina of the Canadian Cardiovascular Society Classification. The indications were: de novo lesions (30%), suboptimal angioplasty results (54%), acute occlusion (8%) or restenosis (8%). The stents of 3.0 to 4.0 mm diameter were implanted in the left main coronary artery (1%) the left anterior descending artery (20%), the left circumflex artery (19%), the right coronary artery (44%) or a venous bypass graft (7%) after intravenous injection of 15,000 IU of heparin. Daily treatment with aspirin 100 mg and ticlopidine 500 mg was instituted from the day of the procedure. The success rate was 98.5% with only 3 technical failures. The minimal luminal diameter and percentage stenosis ranged from 0.80 +/- 0.2 mm and 74 +/- 13% before to 2.66 +/- 0.38 mm and 15 +/- 7% after the procedure in vessels with an average reference diameter of 3.05 +/- 0.35 mm. There were 3% of stent-related immediate clinical complications. In February 1996, 97 patients had survived 6 months. With a 97% follow-up rate, the clinical event rate was 18%. The angiographic follow-up rate was 70% and the restenosis rate was 27%. The authors conclude that the AVE microstents are easy to implant and provide excellent immediate angiographic results with a low complication rate.