JEAN RENKIN, EMMANUEL HAINE, VICTOR UMANS, PIM

Summary Directional Coronary Atherectomy has been introduced as an alternative to conventional balloon angioplasty for the treatment of selected coronary ar­ tery lesions characterized by a proximal localization in a large epicardial vessel and by a complex morphology at angiography. To determine the immediate efficacy of coronary atherectomy we analyzed the first 113 attempts at atherectomy using quantitative angiography obtained in 105 consecutive patients from two centers. Procedural success, defined as a residual coronary diameter stenosis :0;50% associated with effective tissue removal, was obtained in 90 (85 .7%) of 105 patients. The primary angioplas­ tic success rate combining atherectomy and balloon angioplasty in case of failed attempt at atherectomy was 94%. Assessed by quantitative angiogra­ phy analysis, a mean residual minimal luminal diameter of 2.42 ± 0.52 mm and a mean diameter stenosis of 26 ± 15% were obtained immediately after successful directional coronary atherectomy in the 98 treated lesions. Major complications (death, emergency surgery and transmural infarction) were encountered in 5.7% of the patients. In order to evaluate the results of these two interventional techniques we compared 51 atherectomy patients with 51 balloon angioplasty patients individually matched using quantitative angiography according to stenosis location and reference diameter. Atherectomy resulted in larger gains in luminal diameter as the minimal luminal diameter increased from 1.2 ± 0.4 to 2.6 ± 0.4 mm in the atherectomy group and from 1.2 ± 0.3 to 1.9 ± 0.4 mm in the angioplasty group (p < 0.01). As the exact mechanism through which at he recto my enlarges the vessel lumen remains uncompletely understood , we evaluated a potential Dotter effect in 13 patients by performing quantitative angiography analysis before atherectomy, immediately after for- and backwards crossing the stenosis with the catheter but without inflation and cutting, and finally at the end of the successful procedure. The data suggest that simply crossing the stenosis with the atherectomy catheter contributes by more than 50% to the final luminal