AbstractThe success of percutaneous transluminal coronary angioplasty is limited by acute occlusion and late restenosis. In 25 patients (20 men, 5 women, age range 36–81 years) coronary angioplasty was performed using a new cutting balloon into which 3–4 longitudinally orientated blades are incorporated so as to reduce the rate of severe dissections. In 12 patients stenoses were reduced from 83.9 ± 7.8% to 28.4 ± 10.7% (mean ± SD) by the cutting balloon alone, using predilatation with a small conventional balloon in two cases. Thirteen other patients were additionally dilated with a conventional balloon because of a residual stenosis > 50% after cutting balloon angioplasty. Here the stenoses could be reduced from 78.1 ± 8.7% to 29.1 ± 11.3%. Six months follow‐up angiography in 14 patients showed > 50% restenosis in two of seven patients dilated with a conventional balloon in addition to the cutting balloon, and in one of seven patients dilated with the cutting balloon alone but predilated with a small conventional balloon. These results show that coronary angioplasty by the new cutting balloon results in a stenosis reduction comparable with conventional balloons at a low complication rate. Available 6 months follow‐up data show three restenoses in patients either pre‐ or postulated by a conventional balloon and none in stand‐alone cutting balloon cases.