Restenosis after coronary angioplasty: new standards for clinical studies.

With the high initial success rates for coronary angioplasty that are reported regularly, it has become increasingly difficult to demonstrate methods or techniques that are able to provide more beneficial early results than can be achieved by conventional angioplasty. On the other hand, the incidence of late restenosis has remained much the same over the 10 years that angioplasty has been part of clinical practice, and there is still no proved intervention that modifies the restenosis process. Therefore, the problem of restenosis has assumed increasing relevance in determining the clinical value of coronary angioplasty and, accordingly, studies that address the problem of restenosis need to become more exacting. Although numerous articles have addressed the problem of restenosis in the clinical setting, many defining certain factors associated with restenosis and possible interventions to reduce the incidence of restenosis, there is surprisingly little consensus. Most of the discrepancies can be attributed to three factors: 1) the selection of patients, 2) the method of analysis, and 3) the definition of restenosis employed. This review shows how these three factors influence the outcome and conclusions of restenosis studies.