EXPERIENCE WITH LOW-DOSE INTRACORONARY RECOMBINANT TISSUE-TYPE PLASMINOGEN-ACTIVATOR FOR NONACUTE TOTAL OCCLUSIONS BEFORE PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

The primary success rate for angioplasty of total occlusions is significantly worse than for subtotal tal lesions. Pharmacologic recanalization of total occlusions before angioplasty has the potential to improve the primary success rate. To determine the ability of recombinant tissue-type plasminogen activator (rt-PA) to recanalize occlusive thrombi before elective percutaneous transluminal coronary angioplasty, 12 patients with total occlusions, 100% obstruction and Thrombolysis in Myocardial Infarction (TIMI) grade 0 flow, and 5 with functional total occlusions, severe stenoses and TIMI grade 1 flow received an intracoronary infusion of rt-PA. The first 10 patients received 0.2 mg/min for 90 minutes, and the next 7 patients received 0.4 mg/min for 60 minutes. Flow improved by greater-than-or-equal-to 1 TIMI grade in 11 patients. Mean TIMI flow improved from 0.3 +/- 0.5 to 1.5 +/- 1.2 (P < 0.0001). There was a significant improvement in severity of stenosis after rt-PA in. fusion by both digital caliper (99 +/- 2 vs 84 +/-16%; p < 0.0001) and quantitative videodensitometric area assessment (99 +/- 3 vs 94 +/- 6%; p < 0.004). Angioplasty was successful in 16 of 17 patients (94%). There were 2 out-of-laboratory abrupt closures at 4 days; both were medically treated and 1 had a small myocardial infarction. Only 1 patient had a bleeding complication significant enough to need a transfusion. It is concluded enough low-dose intracoronary rt-PA is effective at lysing thrombi < 3 weeks old. This approach warrants further investigation since it may significantly improve the primary success rate of percutaneous transluminal coronary angioplasty in patients with occlusive thrombus.