LOWER EXPRESSION OF NEUTROPHIL ADHESION MOLECULE INDICATES LESS VESSEL WALL INJURY AND MIGHT EXPLAIN LOWER RESTENOSIS RATE AFTER CUTTING BALLOON ANGIOPLASTY

Background-The Cutting Balloon is a novel dilatation catheter for coro nary angioplasty (InterVentional Technologies Inc). It produces longit udinal, microsurgical incisions in the vessel waif before the actual d ilatation. It is assumed that these controlled surgical incisions reli eve hoop stress and reduce vessel wall injury and eventually restenosi s. However, no clinical indicator to support the theory of reduced inj ury has been described. Certain clusters of differentiation leg, CD11, CD18 on the leukocytes) are implicated in leukocyte adhesion, increas ed permeability, and opsonization. Therefore, they might serve as clin ical indicators of the injury level of the vessels after angioplasty. Methods and Results-We randomly selected 64 patients with isolated lef t anterior descending coronary artery disease for either Cutting Ballo on angioplasty or conventional balloon angioplasty. The expression of CD18 and CD11b on the surface of neutrophils was determined by flow cy tometric analysis. Serum levels of soluble intercellular adhesion mole cule-1 (sICAM-1) were also measured. The expression of both the CD18 a nd CD11b in the coronary sinus blood gradually increased and reached i ts maximum at 48 hours after angioplasty. The sICAM-1 levels in the co ronary sinus serum also increased after angioplasty. Percentage increa ses of CD18 and CD11b expression and the increase of the sICAM-1 level s at 48 hours after angioplasty las ratios to baseline values before a ngioplasty) were less in the Cutting Balloon angioplasty group than in the conventional balloon angioplasty group (CD18, 1.10 +/- 0.05 versu s 1.31 +/- 0.05, P<0.05; CD11b, 1.23 +/- 0.06 versus 1.72 +/- 0.10, P< 0.001; sICAM-1, 1.12 +/- 0.05 versus 1.25 +/- 0.02, P<0.05). In all pa tients, the late lumen loss at follow-up angiogram positively correlat ed with the increased levels of CD11b (R=0.59, P<0.001) and sICAM-1 (R =0.38, P<0.05) at 48 hours after angioplasty. Conclusions-Balloon angi oplasty upregulated Mac-1 (CD11b/CD18) on the surface of the neutrophi ls and increased sICAM-1 levels in association with late loss increase . These changes were significantly smaller in the Cutting Balloon angi oplasty group than in the conventional balloon angioplasty group, This suggests that Cutting Balloon angioplasty may produce less vessel wal l injury and, consequently, less neutrophil activation, which may acco unt for the lower rate of restenosis.