Reasons for the lack of benefit of immediate angioplasty during recombinant tissue plasminogen activator therapy for acute myocardial infarction: A regional wall motion analysis

Abstract

Regional ventricular wall motion analysis utilizing three different methods was performed on predischarge left ventriculograms from 291 of 367 patients enrolled in a randomized triai of single chain recombinant tissue-type plasminogen activator (rt-PA), aspirin and heparin with and without immediate angioplasty in patients with acute myocardial infarction.With univariate analysis, no difference in regional wall motion variables between the two treatment groups was observed. However, with individual baseline risk assessment by multivariate linear regression analysis using baseline characteristics known to be related to left ventricular function after thrombolytic therapy or outcome of coronary angioplasty, or both, an excess of high risk patients in the invasive treatment group was detected. To adjust for this unequal distribution of baseline risk, multivariate linear regression analysis was performed. No benefit of immediate coronary angioplasty was observed after adjustment.Reocclusion or reinfarction, or both, occurred more frequently in the invasive than in the noninvasive treatment group (18% versus 13%, respectively). Among patients with a patent infarct-related vessel on angiography between days 10 and 22 and without reinfarction before angiography, there was a trend toward benefit from the invasive strategy, indicating that reocclusion and reinfarction might be responsible for the lack of benefit of the invasive strategy. This implies that immediate coronary angioplasty may be beneficial in selected patients, provided that these complications can be prevented.