RESTENOSIS AFTER DIRECTIONAL CORONARY ATHERECTOMY AND BALLOON ANGIOPLASTY - COMPARATIVE-ANALYSIS BASED ON MATCHED LESIONS

Objectives. Late lumen narrowing after directional coronary atherectom y was assessed by quantitative coronary angiography and compared with that after balloon angioplasty. Background. Directional coronary ather ectomy has been introduced as an alternative technique for balloon ang ioplasty and may reduce the incidence of restenosis. Methods. A prospe ctively collected consecutive series of 87 native coronary artery lesi ons successfully treated with atherectomy were matched with 87 coronar y artery lesions selected from a consecutive series of lesions that ha d been successfully dilated by balloon angioplasty. Late angiographic analysis was performed in 158 lesions. The net gain index represents t he ultimate gain in minimal lumen diameter at follow-up study, normali zed for the vessel size. This index is the result of the relative gain attained during the procedure (the ratio of the change in minimal lum en diameter and reference diameter) and the relative loss observed dur ing the follow-up period (the ratio of the change in minimal lumen dia meter during the follow-up period and the reference diameter). Results . Matching for clinical and angiographic variables resulted in two com parable groups with similar baseline stenosis characteristics. Atherec tomy resulted in a more pronounced increase in minimal lumen diameter than did balloon angioplasty (mean +/- SD 1.17 +/- 0.29 to 2.44 +/- 0. 42 mm vs. 1.21 +/- 0.38 to 2.00 +/- 0.36 mm, p < 0.001). However, this favorable immediate result was subsequently lost during late angiogra phic follow-up, so that the minimal lumen diameter at follow-up and th e net gain index did not differ significantly between the two groups ( 1.76 +/- 0.62 vs. 1.77 +/- 0.59 mm, p = 0.93, and 0.18 +/- 0.19 vs. 0. 17 +/- 0.17, p = 0.70). Consequently, the relative gain and relative l oss were higher in the atherectomy group. For both techniques, the rel ative gain was linearly related to the relative loss but the slope of the regression line was steeper for atherectomy, suggesting that the r elative loss in the atherectomy group is proportionally even larger fo r a given relative gain compared with that in the angioplasty group. C onclusions. In matched groups of patients, atherectomy induces a great er initial gain in minimal lumen diameter than does balloon angioplast y. However, the vascular wall injury induced by the device is, of a di fferent nature (debulking vs. dilating) that leads to more relative lo ss over the follow-up period in the atherectomy group.