Comparative study of antithrombotic effect of a low molecular weight heparin and unfractionated heparin in an ex vivo model of deep arterial injury.
Thrombosis after plaque rupture triggers the onset of acute coronary events. The treatment of choice for patients with acute coronary syndromes is conventional unfractionated heparin. Low molecular weight heparin has recently been reported to be as effective and even safer than unfractionated heparin. In this study, the effects of the low molecular weight heparin reviparin and unfractionated heparin on thrombus formation were examined under dynamic conditions using an extracorporeal perfusion chamber in a porcine model. Thrombus formation was assessed by the deposition of porcine 123I-fibrin(ogen) and autologous 111In-platelets on porcine tunica media at high and low shear rates. Reviparin reduced the fibrinogen molecules deposited on injured vessels at high shear rates (252+/-80 molecules x 10(12)/cm2 for reviparine (200 U/kg/hour) vs. 624+/-70 x 10(12)/cm for unfractionated heparin (200 U/kg/hour) (p<0.05). At low shear rates, fibrinogen deposition was also significantly reduced by reviparin (130+/-15 molecules x 10(12)/cm2) compared to unfractionated heparin (192+/-40 x 10(12)/cm2 at 200 U/kg/hour; p<0.05). No change in platelet deposition was detected after heparin administration in either treatment group. In conclusion, the low molecular weight heparin reviparin has a higher antithrombotic potential than unfractionated heparin. Reviparin may have advantages over unfractionated heparin in treatment and prevention of acute coronary syndromes.
Roqué
M
M
Cardiovascular Biology Research Laboratory, The Zena and Michael A. Wiener Cardiovascular Institute, The Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
Rauch
U
U
Reis
E D
ED
Chesebro
J H
JH
Fuster
V
V
Badimon
J J
JJ
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001158:Arteries / Q000293:injuries; D001780:Blood Coagulation Tests; D001783:Blood Flow Velocity; D003094:Collagen / Q000494:pharmacology; D004195:Disease Models, Animal; D005337:Fibrin / Q000187:drug effects / Q000378:metabolism; D005340:Fibrinogen / Q000187:drug effects / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000494:pharmacology; D006403:Hematologic Tests; D006493:Heparin / Q000494:pharmacology*; D006495:Heparin, Low-Molecular-Weight / Q000494:pharmacology; D010477:Perfusion; D010974:Platelet Aggregation / Q000187:drug effects; D010979:Platelet Function Tests; D013552:Swine; D013927:Thrombosis / Q000188:drug therapy* / Q000378:metabolism
D005343:Fibrinolytic Agents; D006495:Heparin, Low-Molecular-Weight; C094240:reviparin; D000244:Adenosine Diphosphate; D005337:Fibrin; D005340:Fibrinogen; D006493:Heparin; D003094:Collagen