Low-dose intermittent urokinase therapy in chronic symptomatic end-stage arterial disease--clinical relevance for patients with coronary artery disease or peripheral arterial occlusive disease.

Symptomatic end-stage arterial disease in coronary artery or peripheral arterial occlusive disease represents an increasing clinical problem as cardiovascular mortality in these patient groups has declined due to improved secondary prevention. While in peripheral arterial occlusive disease amputation with subsequent life-long physical disability is the major problem, patients with end-stage coronary artery disease and refractory angina pectoris repeatedly report to the emergency ward with the clinical symptoms of unstable coronary syndromes, but myocardial infarction is generally ruled out. For these patients long-term intermittent urokinase therapy has been developed as an alternative treatment modality. Potential mechanisms for clinical effectiveness include improvement of rheological blood properties, thrombolysis of non-occluding arterial thrombi and possibly plaque regression. In coronary artery disease urokinase is applied as an intravenous bolus injection of 500,000 IU urokinase three times a week over a period of 12 weeks. This leads to a marked reduction of fibrinogen by about 35% and of clinical symptoms by around 70% accompanied by a reduction of exercise-induced myocardial ischemia. In observational studies in patients with peripheral arterial occlusive disease injections of 500,000 IU of urokinase were usually given daily for a shorter time period of three to four weeks with a clinical success rate, defined as a cessation or marked reduction of rest pain and/or salvage of a limb, of around 50%. Given the state of critical ischemia in both entities of atherosclerotic disease, long-term intermittent urokinase therapy represents a promising antiischemic approach. In particular in patients with peripheral arterial occlusive disease randomized controlled trials with prolonged treatment periods, which are likely to improve clinical results, are warranted.