Aggressive intervention for myocardial infarction: angioplasty, stents, and intra-aortic balloon pumping.

Primary percutaneous transluminal coronary angioplasty (PTCA) is not used in all hospitals capable of performing it because the data regarding results are either not known or not easily interpreted. Unlike pharmaceutical trials, which receive $30-50 million in research funds, virtually all trials of PTCA have been unfunded. Nevertheless, several groups have conclusively proved the benefit of primary PTCA over thrombolysis. In a 1995 meta-analysis, PTCA proved superior to thrombolytic therapy in reducing death and reinfarction. The Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-IIB) substudy confirmed this fact with 94% certainly. Other studies were designed to refine the angioplasty technique. In the Primary Angioplasty in Myocardial Infarction (PAMI-I) study, acute catheterization was used to stratify patients and identified a low-risk population whose mortality equaled that of patients treated electively. Compared with clinical risk factors, angiographic findings enhanced the power to predict mortality three-fold. The high-risk subset with acute myocardial infarction (MI) was also randomized to treatment with or without prophylactic intra-aortic balloon pumping (IABP). Although IABP caused no complications, it had no positive effect on primary endpoints (death, recurrent MI, and reocclusion) and did not improve left ventricular function at 6 months. One limitation of primary PTCA is a high rate of late restenosis (30-50% at 6 months). In a pilot study we are examining the role of stents in conjunction with primary PTCA. Early results indicate that in the 69% of patients eligible for stent placement, in-hospital events were uncommon (no deaths, no reinfarctions, low rate of recurrent ischemia) and the need for repeat revascularization was infrequent.