Usefulness of coronary artery angioplasty strategies in acute myocardial infarction

The usefulness of percutaneous transluminal coronary angioplasty (PTCA) as an adjunct to thrombolytic therapy for acute myocardial infarction is the focus of intense clinical investigation. With an angiographically significant residual stenosis present in the infarct vessel in at least 70% of cases, PTCA has the potential to resolve residual ischemia of surviving myocardium; provide a route for nutrient influx to promote healing and reorganization by leukocytes and fibroblasts; and maintain ventricular wall integrity. Additionally, the residual lesion may interfere with flow to collateral vessels supplying other diseased vascular territories, or inhibit the delivery of inotropic or antiarrhythmic agents to a problematic peri-infarct region. Various angioplasty strategies have been devised to define the optimal timing of PTCA in several clinical settings. Although the impact on resting left ventricular performance has been disappointing except in cases of cardiogenic shock, an approach involving early angiography with thoughtful triage to PTCA when feasible, has been associated with improved survival at one- to three-year follow-up, compared with a 'thrombolysis only' approach. The results of clinical trials investigating the role of PTCA as a direct method of revascularization; as a 'rescue' procedure following failed thrombolysis; as an empiric, immediate or deferred strategy; or as an elective adjunct to thrombolytic therapy only in the presence of subsequent ischemia are reviewed in detail.