Improved fibrinolysis after one year of treatment with enalapril in men and women with uncomplicated myocardial infarction.

Aims: To study long-term effects of enalapril on mass concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI-1), tPA/PAI-1-complex and von Willebrand factor (vWF) in both genders with uncomplicated myocardial infarction.

Methods And Results: More than three months after an uncomplicated myocardial infarction 82 survivors (46 males, 36 females) were randomised to enalapril/placebo. PAI-1, tPA, tPA/PAI-1-complex and vWF were measured after two weeks, six and 12 months following randomisation. PAI-1 decreased significantly in both genders in the enalapril-treated group after two weeks, with a maximum decrease at six months (mean reduction: 31% equal to 9.8 microg x L(-1), CI: 5.2 to 14.5 microg x L(-1), p = 0.0001) and remained significantly lower at 12 months. Mass concentration of tPA decreased significantly (mean reduction: 1.81 microg x L(-1), CI: 0.903 to 2.708 microg x L(-1), p < 0.001) after two weeks treatment in both genders but returned to baseline values at 12 months. The tPA/PAI-1-complex decreased and was significantly lower (mean reduction 0.96 microg x L(-1), CI: 0.36 to 1.56 microg x L(-1), p = 0.003) in the enalapril group after two weeks and six months (p = 0.037). No decrease of vWF was seen in the enalapril group.

Conclusions: Enalapril treatment up to one year depressed mass concentrations of PAI-1 and transiently tPA and tPA/PAI-1 complex indicating an improvement of the fibrinolytic balance in both genders with uncomplicated myocardial infarction.