UNLABELLED: Directional coronary atherectomy was developed to decrease the incidence of restenosis. Among the first 61 patients treated with directional atherectomy at Mayo Clinic, 50 have been considered a success. Half of the patients had had one or more previous PTCA performed on the target lesion. Patients were followed during 6 months. Coronary angiogram was performed 6 months after atherectomy or earlier if ischemia appeared. Restenosis was defined as a greater than or equal to 50% luminal narrowing or loss of greater than or equal to 50% of the initial gain. Ischemia was documented in 23 patients. Control angiogram demonstrated restenosis in 24 patients (48%). Among those 24 patients, 18 had ischemia documented during stress test or at rest, and underwent a second procedure (second atherectomy in 4, PTCA in 8 and bypass surgery in 6 patients). Neither previous procedures nor the type of vessel significantly influenced restenosis rates. CONCLUSIONS: coronary restenosis was not less frequent after directional atherectomy, than after conventional balloon angioplasty. Previous procedures or type of vessel did not influence restenosis incidence.