Influence of the methodology of percutaneous transluminal coronary angioplasty on restenosis.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) remains the principal factor preventing broader application of this form of myocardial revascularization. Several methodologic variables contribute to the quality of the angioplasty result and may directly or indirectly influence restenosis rates after the procedure. PTCA operators attempt to minimize thrombotic activity at the angioplasty site by delaying PTCA when thrombus is present, with heparin and antiplatelet agents and with thrombolytic agents if thrombus is identified during the procedure. Therapy directed at preventing coronary artery spasm with nitrates and calcium antagonists has no proven efficacy in preventing restenosis. Residual stenosis and pressure gradient have been shown to be predictors of restenosis. Retrospective studies have indicated that a balloon to artery diameter ratio greater than 1 favors long-term patency; however, preliminary results of a prospective randomized study suggested that acute complications were more frequent with larger balloons. The interplay of other balloon-related variables (maximal inflation pressure, number of inflations, duration of inflations, balloon material and length of balloon) and the potential influence on restenosis are discussed. Recommendations for patient management after PTCA are also offered. A number of prospective randomized trials using antiplatelet agents and modification of risk factors are underway to test ability of these strategies to influence restenosis.