Author + information
- Received November 24, 1993
- Revision received January 28, 1994
- Accepted February 2, 1994
- Published online July 1, 1994.
- Robert A. Wright, MRCPc,∗,
- Andrew D. Flapan, MRCPc,
- K.George M.M. Alberti, FRCPb,
- Christopher A. Ludlam, FRCPa and
- Keith A.A. Fox, FRCPc
- ↵∗Address for correspondence: Dr. Robert A Wright, Department of Cardiology, Royal Infirmary, 1, Lauriston Place, Edinburgh EH3 9YW, United Kingdom.
Objectives. This study investigated the effects of captopril therapy on endogenous fibrinolysis in men with recent, uncomplicated myocardial infarction.
Background. Angiotensin-converting enzyme inhibitors reduce the incidence of acute coronary syndromes in patients with mild left ventricular dysfunction after myocardial infarction. Abnormal endogenous fibrinolysis, reflected in increased levels of endogenous tissue-type plasminogen activator (t-PA) antigen and plasminogen activator inhibitor type 1 activity, is associated with an increased risk of myocardial infarction in patients with ischemic heart disease.
Methods. In a randomized, double-blind crossover study beginning 8 weeks after uncomplicated myocardial infarction, patients received 4 weeks of placebo and 4 weeks of captopril (75 mg daily) therapy. At the end of each treatment period, we measured t-PA antigen and plasminogen activator inhibitor type 1 antigen and activity.
Results. Median values in the 15 patients after placebo and in 12 normal men matched for age and body mass index were, respectively, t-PA antigen 16.0 versus 9.5 ng/ml (p = 0.001), plasminogen activator inhibitor type 1 antigen 17.3 versus 8.6 ng/ml (p = 0.29) and plasminogen activator inhibitor type 1 activity 13.2 versus 6.3 AU/ml (p = 0.04). After 4 weeks of treatment with captopril in the 15 patients, the estimated (95% confidence interval) median reduction in t-PA antigen was 7.3 ng/ml (−4.6 to −10.3 ng/ml, p = 0.001), in plasminogen activator inhibitor type 1 antigen 3.1 ng/ml (+1.5 to −8.4 ng/ml, p = 0.17) and in plasminogen activator inhibitor type 1 activity −2.2 AU/ml (−1.0 to −4.3 AU/ml, p = 0.02).
Conclusions. Treatment with captopril after uncomplicated myocardial infarction is associated with a significant decrease in elevated levels of t-PA antigen and plasminogen activator inhibitor type 1 activity. This may help to explain the reduction in risk of coronary thrombosis associated with the use of angiotensin-converting enzyme inhibitors.
☆ This work was supported by the Chest, Heart and Stroke Association, Edinburgh, Scotland, and by the British Diabetic Association, London, England. Supplies of placebo and captopril were kindly donated by Bristol-Meyers Squibb Pharmaceuticals Ltd, London, England, who did not provide any financial support.
- Received November 24, 1993.
- Revision received January 28, 1994.
- Accepted February 2, 1994.