Fibrinolytic/hemostatic variables in arterial hypertension: response to treatment with irbesartan or atenolol

Essential hypertension is often accompanied by abnormalities of the coagulation/fibrinolytic system, predisposing to a procoagulant state. The aim of the present study was to compare the effects of atenolol (beta1-blocker agent) and irbesartan (angiotensin II type 1 receptor antagonist) on plasma levels of hemostatic/fibrinolytic and endothelial function markers in a cohort of previously untreated hypertensives. Fifty-four patients were randomly assigned to atenolol 25 to 150 mg (26 patients) or irbesartan 75 to 300 mg (28 patients). The plasma levels of plasminogen activator inhibitor-1 antigen, thrombomodulin, tissue factor pathway inhibitor antigen, fibrinogen, and factor XII were determined before and after 6 months of therapy. Age, gender distribution, body mass index, lipid profile, and baseline values of the measured markers were similar in both groups. Baseline values for systolic and diastolic blood pressure, as well as the reduction after treatment, were not significantly different between the two groups. Treatment with irbesartan was associated with a significant decrease in the levels of all the parameters. Similar findings were observed in the atenolol group, except for factor XII and tissue factor pathway inhibitor levels, which were not significantly decreased in this group. The reduction, however, of fibrinogen, plasminogen activator inhibitor-1, and thrombomodulin was significantly greater in the irbesartan than in the atenolol group. In conclusion, the results indicated that, despite an equally controlled blood pressure, 6-month therapy with irbesartan was associated with a more favorable modification of hemostatic/fibrinolytic status than atenolol.