Antithrombotic treatment in stable coronary syndromes: long-term intermittent urokinase therapy in end-stage coronary artery disease and refractory angina pectoris

Long-term Urokinase Therapy and Isovolemic Hemodilution: A Clinical and Hemodynamic Comparison in Patients with Refractory Angina Pectoris

Antiischemic effectiveness of long-term urokinase therapy and isovolemic hemodilution therapy has been reported in patients with symptomatic coronary artery disease, but both interventions have never been compared. In patients with refractory angina pectoris and end-stage coronary artery disease (clinical functional class III), isovolemic hemodilution (n = 9) (hydroxyethyl starch solution 6%, 1-2 times/week), and urokinase therapy (n = 11) (500,000 U urokinase per i.v. injection, 3 times a week) were performed over a period of 12 weeks, each additionally to maximal conventional treatment. Apart from the assessment of clinical symptoms and rheologic parameters, invasive hemodynamic measurements were carried out at rest and during exercise testing before and after treatment. After treatment with urokinase, patients showed a significant reduction of clinical symptoms (from 19.8 +/- 6.5 to 5.0 +/- 4.3 anginal events/week, p < 0.001), fibrinogen (from 410 +/- 88 to 238 +/- 40 mg/dl, p < 0.001), plasma viscosity (from 1.45 +/- 0.10 to 1.33 +/- 0.03 mPa x s-1, p < 0.01), and no changes of hematocrit (from 0.45 +/- 0.02 to 0.45 +/- 0.02) and whole blood viscosity (from 4.7 +/- 0.5 to 4.4 +/- 0.7 mPa x s-1); however, hemodilution resulted in a decrease of hematocrit (from 0.46 +/- 0.01 to 0.39 +/- 0.01, p < 0.001) and whole blood viscosity (from 4.7 +/- 0.5 to 4.0 +/- 0.3 mPa x s-1, p < 0.001) and no changes of initially comparable levels of clinical symptoms, fibrinogen, and plasma viscosity. Hemodynamic parameters at rest improved after urokinase therapy with a reduction of pulmonary capillary wedge pressure (from 9.1 +/- 5.1 to 5.5 +/- 2.8 mmHg, p < 0.05) at comparable levels of systemic vascular resistance (from 1510 +/- 340 to 1420 +/- 510 dyn x s x cm-5). Hemodilution did not result in any significant hemodynamic changes. Apart from clinical symptoms, long-term intermittent urokinase therapy reduces pulmonary capillary wedge pressure at rest. This may reflect an improved diastolic function due to a rheological enhancement of myocardial perfusion at the level of the coronary microcirculation. Isovolemic hemodilution seems to be of no benefit.

Biologic markers as predictors of cardiovascular disease

Epidemiologic data obtained over the past 30 years suggest that a number of new biologic markers are associated with increased risk for cardiovascular disease. These include indices related to (1) altered glucose metabolism, particularly insulin resistance; (2) hyperlipidemia; (3) elevated levels of lipoprotein(a) and homocysteine; (4) increased levels of molecules reflecting decreased fibrinolysis and increased activation of the coagulation cascade; (5) elevations in cell adhesion molecules and other markers of endothelial function; and (6) elevations in molecules associated with infection, inflammation, and vascular remodeling. Changes in molecules associated with increased risk usually occur in clusters. This clustering suggests that effective treatment of one marker may have positive effects on multiple markers. Indeed, several studies have demonstrated that therapies designed to reduce hyperlipidemia may also lower the plasma levels of factors associated with increased coagulation and reduced fibrinolysis. Thus, careful assessment of patient risk factors, and the development of therapies directed toward chains of markers associated with increased risk, may significantly alter the course of cardiovascular disease.

[Conservative therapeutic approaches in terminal coronary heart disease. Chronic intermittent urokinase therapy]

Despite progress in the invasive revascularization procedures and even though conventional antianginal treatment has improved the quality of life in patients with symptomatic coronary artery disease considerably, an increasing number of patients suffers from end-stage coronary artery disease and refractory angina pectoris. For these refractory patients long-term intermittent urokinase therapy was developed as an antithrombotic intervention, which is based on its capacity to enhance thrombolysis and blood rheology, and may possibly lead to plaque regression. The coronary syndrome of refractory angina pectoris is characterized by a mismatch of severe coronary insufficiency and a relatively large amount of viable myocardium as indicated by an only moderately impaired left ventricular function. Prior to initiation of long-term intermittent urokinase therapy all potential measures to improve myocardial perfusion have to be considered in each patient. These supportive measures include rigorous reduction of LDL-cholesterol, which has proven antiischemic properties due to an improved endothelial function of epicardial conductance vessels possibly resulting in an antianginal effect. Apart from the proven antiischemic properties of long-term intermittent urokinase therapy in patients with refractory angina pectoris, objective signs of ischemic myocardial heart failure improve. Follow-up studies demonstrated a significant increase of left ventricular ejection fraction as evaluated with multi-gated blood pool analysis. Furthermore, left ventricular diastolic function normalized after a treatment period of 12 weeks. As the clinical effects last well beyond the actual treatment period and as they are accompanied by a remarkable increase in the quality of life, a complex approach as this one is justified in this highly symptomatic patient group.