Optimal use of directional coronary atherectomy is required to ensure long-term angiographic benefit: A study with matched procedural outcome after atherectomy and angioplasty

Objectives. This study was designed to examine whether restenosis is related to the extent or mechanism of lumen improvement and to explore angiographic determinants of optimal atherectomy. Background. Directional atherectomy induces a greater extent of immediate gain and late loss but has not been found to yield a better late angiographic lumen than angioplasty in randomized trials. The difference in lumen renarrowing may be related to either the extent or the mechanism of immediate gain. The design of previous studies has precluded the detection of a device-specific effect on restenosis. Methods. A retrospective analysis was based on matching a prospectively collected series of 80 native coronary arteries successfully treated with atherectomy with a prospectively collected series of 80 native coronary arteries successfully treated with balloon angioplasty. Angiographic analysis was performed in 160 lesions to explore whether a specific device-related effect exists. Multivariate analyses were performed to determine the correlates of minimal lumen diameter at follow-up and late lumen loss and to identify the procedural characteristics for optimal atherectomy. Results. Matching resulted in two comparable groups with equivalent baseline clinical and stenosis characteristics. By study design, atherectomy and angioplasty resulted in similar mean (±SD) immediate lumen gain (1.15 ± 0.44 vs. 1.10 ± 0.40 mm, p = 0.50). However, lumen loss was more pronounced after atherectomy, and, thus, the minimal lumen diameter at follow-up differed significantly between the two groups (1.78 ± 0.57 vs. 2.00 ± 0.56 mm, p = 0.001). Device type was retained in the multivariate analysis as an independent predictor of late minimal lumen diameter and lumen loss. Multivariate analysis identified vessel size and immediate gain as determinants of optimal atherectomy. Conclusions. Restenosis is a consequence not only of the extent of lumen improvement but also of the mechanism of vessel wall injury (debulking vs. dilating). While performing atherectomy, the operator should strive for an optimal procedural result to accommodate an increased intimal hyperplastic response.