Prospective, randomized trial of prolonged intracoronary urokinase infusion for chronic total occlusions in native coronary arteries
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F J Zidar1, B M Kaplan, W W O'Neill
1Department of Cardiology, Department of Medicine, William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
Insights
Intracoronary urokinase infusion safely facilitates angioplasty for chronic total coronary occlusions. Lower doses are as effective as higher doses, with fewer bleeding complications, though restenosis remains a concern.
Area of Science:
- Cardiology
- Interventional Cardiology
- Vascular Medicine
Background:
- Percutaneous transluminal coronary angioplasty (PTCA) for chronic total occlusions (>3 months) has low success rates due to guide wire passage difficulties.
- Chronic total occlusions present a significant challenge in interventional cardiology, often requiring advanced techniques to achieve successful revascularization.
Purpose of the Study:
- To evaluate the safety and efficacy of three different dosing regimens of intracoronary urokinase for facilitated angioplasty in chronic total coronary artery occlusions.
- To determine the optimal dose of urokinase for improving angioplasty success rates while minimizing complications.
Main Methods:
- Sixty patients with chronic total coronary occlusions, where standard guide wire passage failed, were randomized into three groups receiving 8-hour intracoronary urokinase infusions (0.8, 1.6, or 3.2 million units).
- Angioplasty was reattempted after urokinase infusion; success rates, bleeding complications, and procedural outcomes were assessed.
- Angiographic follow-up was performed to evaluate target vessel patency and restenosis rates.
Main Results:
- Coronary angioplasty was successful in 53% of patients, with no significant difference between the urokinase dosing groups (52% to 59%).
- Lower-dose urokinase (0.8 million units) was associated with significantly fewer major bleeding episodes compared to higher doses (p < 0.05).
- Angiographic follow-up showed 91% patency but a high restenosis rate of 59% among successfully treated patients.
Conclusions:
- Prolonged intracoronary urokinase infusion is a safe method to facilitate angioplasty of chronic total coronary occlusions.
- Lower doses of intracoronary urokinase are as effective as higher doses and lead to fewer bleeding complications.
- While vessel patency is often achieved, restenosis remains a significant long-term challenge after this intervention.
Objectives:
The purpose of this study was to determine the safety and efficacy of three dosing regimens of intracoronary urokinase for facilitated angioplasty of chronic total native coronary artery occlusions.
Background:
Percutaneous transluminal coronary angioplasty of chronically occluded (>3 months) native coronary arteries is associated with low initial success secondary to an inability to pass the guide wire beyond the occlusion.
Methods:
Patients were enrolled if a chronic total occlusion >3 months old could not be crossed with standard angioplasty equipment. Of the 101 patients enrolled, 41 had successful guide wire passage and were excluded from urokinase treatment. The remaining 60 patients were randomized to receive one of three intracoronary dosing regimens of urokinase over 8 h (group A = 0.8 million U; group B = 1.6 million U; group C = 3.2 million U), and angioplasty was again attempted after completion of the urokinase infusion in 58 patients.
Results:
Coronary angioplasty was successful in 32 patients (53%) (group A 52%, group B 50%, group C 59%, p = 0.86). This study had a 90% power to detect at least a 50% difference between dosing groups at alpha 0.05. Bleeding complications requiring blood transfusion did not differ significantly among the dosing groups (A 0%, B 15%, C 6%, p = 0.14), although major bleeding episodes were less common in group A (p < 0.05). There were no major procedural or in-hospital complications. Angiographic follow-up in 69% of the patients with successful angioplasty revealed target vessel patency in 91% but an angiographic restenosis rate of 59%.
Conclusions:
A prolonged supraselective intracoronary infusion of urokinase can be safely administered and may facilitate angioplasty of chronic total occlusions. Lower doses of urokinase are equally effective and result in fewer bleeding complications than do higher dosage regimens. Vessel patency is frequently maintained, but restenosis remains a problem.