Intracoronary recombinant tissue-type plasminogen activator in unstable angina: a pilot angiographic study.

The effectiveness of intracoronary (IC) recombinant thromboplastin activator (rt-PA) was prospectively evaluated in seven patients with unstable angina and complex angiographic lesions or intracoronary filling defects (ICFD). There were four men and three women, with a mean age of 60 years. Three patients had multivessel disease and all patients had rest angina; none had evolving myocardial infarction. All patients were pretreated with aspirin and were given heparin. IC rt-PA was infused at the rate of 1 mg/min to a total of 50 mg, and angiographic changes were observed every 15 minutes. At 50 minutes, angiographic improvement was seen in two patients (28%), one of whom had complete and one of whom had partial resolution of ICFD. In two patients (28%) there was no change in the lesion, and three patients (42%) had worsening of the lesion appearance. In two of the latter, paradoxical closure was observed at the end of the infusion, and was treated successfully with ad hoc emergency angioplasty. This pilot study suggests that IC rt-PA at the dosage used may have variable effects on complex coronary lesions associated with unstable angina, and this may be of relevance in further trials evaluating IC thrombolysis in unstable coronary ischemic syndromes.