We investigated the acute-phrase and chronic-phase outcomes of patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) with or without antecedent mutant tissue-type plasminogen (t-PA) administration.

Thirty-nine patients with a first AMI within 6 hours of onset were randomly assigned to the treatment group (1,600,000 IU IV monteplase, n = 19) or the nontreatment group (n = 20), followed by PCI. Clinical outcomes were then evaluated.

Patient characteristics did not differ between the 2 groups. A significantly higher number of patients in the monteplase group achieved Thrombolysis In Myocardial Infarction trial (TIMI) grade 2 flow or more at the first angiography (84.2% vs 40.0%; P < .005), reduced number of devices (1.44 vs 1.80 devices, P < .05), and reduced procedure times (59.7 vs 86.7 minutes; P < .01), with no differences in peak creatine kinase and rates of major complications and no reflow or distal embolization. Observation over an average of 5.5 months revealed a tendency toward lower target lesion revascularization rates in the monteplase group (17.6% vs 31.6%) but no intergroup difference in rates of major complications. Pretreatment quantitative coronary angioplasty only showed a significant difference in minimal lumen diameter and percent diameter stenosis in the acute phase (1.13 mm in the monteplase group vs 0.66 mm in the nontreatment group, 57.0% vs 73.0%; P < .05). ^99mTc-QGS (quantitative electrocardiographically gated single-photon emission computed tomographic scintigraphy) showed no intergroup differences in left ventricular end-diastolic volume index, end- systolic volume index, and ejection fraction in the acute and chronic phases.

Our results suggest that PCI with antecedent mutant t-PA for AMI not only accelerates reperfusion, thereby facilitating PCI, but also attenuates restenosis in the chronic phase.