The Chronic And Acute Effects Of Enhanced External Counterpulsation On Fibrinolytic Proteins In CVD Patients

Abstract

Enhanced external counterpulsation (EECP) has been shown to reduce angina and improve exercise tolerance. However, the fibrinolytic responses of treatment have yet to be determined. PURPOSE Chronic (35 sessions at 60 minutes) and acute (pre and post one session) effects of EECP on tissue plasminogen activator (tPA) and plasminogen activator inhibitor (PAI-1) were evaluated. METHODS Four male cardiac patients (age 67±4.3 years, height 175.9±6.9 cm, weight 95.8±21.1 kg) referred to EECP therapy completed a seven-week, five days/week, one hour/day course of EECP therapy. Venous blood samples were drawn into an acidified citrate solution before the first week of therapy and upon completion of the course of treatment. Acute phase blood draws were performed prior to and immediately following a single treatment. Platelet-poor plasma from these samples was used to determine tPA activity, tPA antigen, and PAI-1 activity, using enzyme-linked immunosorbancy assays. RESULTS There were no differences in tPA activity (pre= 0.64±0.46 IU/ml, post = 0.61±0.40 IU/ml, p = 0.731), tPA antigen (pre = 11.02±1.33 ng/ml, post = 10.49±1.54 ng/ml, p = 0.46), or PAI activity (pre = 20.92±14.79 IU/ml, post = 20.93±15.11 IU/ml, p = 0.999) following a seven-week course of EECP therapy. There was a significant difference in the acute tPA activity response (pre = 0.65±0.58 IU/ml, post = 0.89±0.59 IU/ml, p < 0.001) for a single EECP session. There was a non-significant trend for acute PAI-1 activity response (pre = 18.95±10.16 IU/ml, post = 13.12±7.25 IU/ml, p = 0.062). Acute tPA antigen response was not significant (pre = 11.08±2.30 ng/ml, post = 10.60±1.64 ng/ml, p =0.52). CONCLUSIONS These preliminary data suggest that EECP therapy acutely improves the fibrinolytic profile of cardiac patients by increasing tPA activity.