Comparison of activation process of platelets and neutrophils after coronary stent implantation versus balloon angioplasty for stable angina pectoris

The pathophysiologic features of stent-induced cellular responses of platel ets and leukocytes have not been established, This study was designed to cl inically investigate the activation of platelets and neutrophils after coro nary stenting and to identify its effects on the longterm results of corona ry stents. Forty-eight consecutive patients with left anterior descending c oronary artery disease indicating coronary intervention were randomly assig ned to either a balloon angioplasty group or a coronary stent group. Flow c ytometric analysis demonstrated that the transcardiac gradient (the value o f coronary sinus blood minus the value of peripheral blood) of platelet sur face expression of CD62P (p <0.001) and CD63 (p <0.01) increased immediatel y after coronary stenting, but increased less significantly immediately aft er balloon angioplasty (CD62P, p <0.01; CD63, p <0.05), These increases wer e persistently observed after coronary stenting but transiently after ballo on angioplasty alone during a 48-hour observation period after the procedur es. The gradient for neutraphil surface expression of CD11b increased, and that of CD62 L decreased 48 hours after coronary stenting (CD11b, p <0.001; CD62 L, p <0.05), but these changes showed less significance 48 hours afte r balloon angioplasty alone (CD1 1b, p <0.05; CD62 L, p = NS), The gradient s 48 hours after the procedures for both CD62P (r = 0.39, p <0.05) and CD11 b (r = 0.44, p <0.01) were independently correlated with the late loss in t he stent group, whereas the correlation was seen only for CD11b (r = 0.38, p <0.05) in the balloon angioplasty group. Both platelet and neutrophil act ivation was greater after coronary stenting than after balloon angioplasty. Cellular interactions between platelets and neutrophils may be related to the progression of neointimal proliferation leading to restenosis after cor onary stent implantation. (C) 2000 by Excerpta Medico, Inc.