OBJECTIVE
To study the prognostic value of von Willebrand factor (vWF) in peracute and acute periods of cardioembolic stroke (CES) in patients receiving unfractionated (UFH) and low molecular weight heparin (LMWH).
MATERIAL AND METHODS
Thirty patients with CES receiving UFH/LMWH and acetylsalicylic acid were examined. The comparison group included 15 patients with non-cardioembolic stroke without heparin therapy. On Days 2—3 and 7—10 from the disease onset, patients were evaluated using the NIHSS and HAS-BLED scales; also, brain CT, Doppler ultrasound, echocardiography, complete blood count and blood chemistry, vWF measurement, and induced platelet aggregation test with ristocetin, arachidonic acid, and collagen were performed.
RESULTS
During LMWH therapy in the peracute period, increased platelet aggregation with ristocetin (p=0.038) and vWF levels (p=0.017) were found versus the comparison group. A correlation between vWF level and platelet aggregation with collagen was identified (p=0.010, r=0.461). No inhibition of platelet function with ristocetin was observed during the entire period of therapy with both LMWH and UFH. During LMWH treatment, increased platelet activity with ristocetin was observed in the acute period, compared with patients receiving UFH (p=0.007). There were no significant differences in the change in the vWF levels in patients with and without hematuria. There was a correlation between the HAS-BLED score and hematuria in the semiquantitative analysis of erythrocytes in urine (p=0.041, r=0.375), as well as a correlation between the vWF levels and the ASPECT score (p=0.001, r=–0.576).
CONCLUSION
The concomitant use of heparin with antiplatelet agents, particularly with aspirin in CES, enhances its anticoagulant activity and inhibits platelets in the test with arachidonic acid. Continued high ristocetin- and collagen-induced platelet aggregation supports the use of vasoprotective agents activating metabolic processes in the walls of blood vessels to correct persistent endothelial dysfunction.