Efficacy of Low-Molecular-Weight Heparin in the Management of Intermittent Claudication

Abstract

Treating chronic arterial occlu sive disease with heparin is contro versial because of the risks associated with long-term anticoagulant ther apy. Low molecular weight (LMW) heparin (mw about 5000 Dalton), which selectively inhibits the Xa fac tor with minimal risk of hemorrhage, seems to offer new possibilities in the prevention and treatment of both ve nous and acute arterial thromboem bolism. Therefore, 44 patients with inter mittent claudication were recruited to a randomized, double-blind, con trolled study. Twenty-two were treated for six months with a single daily subcutaneous dose (15,000 UaXa) of LMW heparin and 22 with placebo administered in the same way over the same period of time. After six months, LMW heparin treatment not only improved walking capacity (by lengthening the pain- free walking time by 25 %) but also significantly modified the hemor rheologic pattern (by reducing fibrin ogen concentrations and whole blood viscosity at low shear rates). LMW heparin also exerted an anti thrombotic and profibrinolytic effect by significantly increasing both the anti-Xa factor and plasminogen ac tivity without markedly modifying activated partial thromboplastin time ( + 20 %). No LMW heparin- treated patient hemorrhaged or re ported other noteworthy side effects. These results suggest LMW hepa rin might be a useful drug in the long- term treatment of chronic arterial occlusive disease of the limbs.