Factors influencing restenosis after coronary angioplasty.

In 1989, it is estimated that coronary angioplasty will be performed in more than 250,000 patients for the relief of ischemic symptoms due to coronary artery disease. Despite its widespread acceptance, the overall success of coronary angioplasty has been limited by the development of recurrent ischemia due to restenosis in approximately 30% of patients undergoing this procedure. Restenosis, due to an excessive fibroproliferative response to endothelial denudation and vessel injury that occurs at the time of vessel dilatation, usually develops within six months after coronary angioplasty. Although a variety of clinical, anatomic, and procedural factors may identify patients at risk for the development of restenosis, intensive pharmacologic and, recently, mechanical interventions have generally been ineffective in its prevention. New therapies, including inhibition of platelet aggregation, receptor blockade of specific vasoactive mediators, and growth factor modification, appear to be promising methods for the future in the prevention of restenosis. Moreover, further refinement of the use of mechanical techniques such as excisional atherectomy, laser, and endoluminal stents may diminish the degree of vascular damage that occurs at the time of vessel dilatation, and attenuate the biologic processes that ultimately culminate in restenosis.