Plasma fibrin clot properties in arterial hypertension and their modification by antihypertensive medication

Background: We sought to determine plasma fibrin clot properties in hypertensive subjects and to evaluate potential effects of antihypertensive therapy on these parameters. Patients and Methods: Sixty-one patients (30 men, 31 women) with essential arterial hypertension stage 1 or 2 (aged 46.6 +/- 14.4 years), free of clinically evident vascular disease, were randomly allocated for monotherapy with one of the 5 antihypertensive agents, i.e. quinapril, losartan, amlodipine, hydrochlorothiazide, or bisoprolol. Plasma fibrin clot permeability, turbidimetry and efficiency of fibrinolysis were investigated at baseline and after 6 months of therapy. Results: Baseline systolic blood pressure in a 24-hour ambulatory monitoring was correlated with clot permeability (r=-0.37, p<0.05), lysis time (r=0.42, p<0.05) and maximal D-dimer concentration released from clots (r=0.45, p<0.05). Antihypertensive treatment resulted in reduction of systolic/diastolic blood pressure in office measurements and 24-hour monitoring (all p<0.001), accompanied by an increase in clot permeability, reduction in clot lysis time and lower maximal D-dimer concentration released from fibrin clots (all p<0.05). No changes were observed in turbidimetric variables. Posttreatment changes in plasma fibrin clot properties were related to reductions in systolic blood pressure, complement component C3 and total cholesterol. Conclusions: Reduction in systolic blood pressure during antihypertensive treatment leads to increased plasma fibrin clot permeation and susceptibility to lysis, which might be a novel antithrombotic mechanism of blood pressure lowering therapy. (C) 2011 Elsevier Ltd. All rights reserved.