he number of patients with arteriosclerosis obliterans (ASO), an atherosclerotic peripheral arterial occlusive disease, is estimated at 500-1,000 individuals per million per year, 1 and the prevalence of intermittent claudication was higher than 1% in a free-living, elderly, North American population. 2 Although bypass operation, stenting and atherectomy are effective therapies for patients with stenosis in the proximal large arteries such as the iliac arteries or femoral arteries, their effects are limited in ASO patients in whom stenotic lesions extend to peripheral small arteries (poor run-off). Enhancement of collateral vessel formation and angiogenesis is a promising therapeutic modality for such non-option ASO patients. Heparin administration reportedly improves the symptoms of ASO Circulation Journal Vol.69, September 2005 patients 9 months after the treatment, 3 and increases the exercise capacity of severe coronary heart disease (CHD) patients by enhancing collateral vessel growth. 4 Recently, investigators have shown that systemic administration of heparin increases the concentration of plasma hepatocyte growth factor (HGF), which promotes neovascularization, [5][6][7] and other studies have shown the effectiveness in ASO and CHD patients of therapeutic angiogenesis using certain growth factors. 8,9 The mechanism of the therapeutic effect of heparin in ASO patients may be strongly related to HGF. There have been no previous studies of whether the combination of an exercise program and heparin administration additionally improves the symptoms of ASO.The aim of the present study was to determine whether a program combining heparin administration with exercise is a useful therapeutic strategy for stimulation of development of collateral circulation in the ischemic legs of patients with non-option ASO.
Methods
Study PatientsAll subjects had severe chronic limb ischemia that lead to claudication within 400 m of walking. None of the subjects was a candidate for non-surgical or surgical revascularization because of the lack of distal target vessels or for other reasons, such as comorbidities that would increase Background A prospective study examined whether a combination of an exercise program and heparin administration improves the clinical symptoms of patients with arteriosclerosis obliterans (ASO) without an indication for surgical revascularization because of the lack of distal target vessels or other reasons such as high surgical risk or lack of a vein conduit from previous coronary artery bypass surgery. Methods and Results A total of 19 consecutive patients with symptomatic non-option ASO diagnosed by angiography were randomly assigned to 3 groups: heparin + exercise (walking for 60 min after heparin injection [3,000 units/day IV for 14 days], n=6), heparin administration only (n=6), and exercise only (n=7). Plasma levels of hepatocyte growth factor (HGF) were serially measured before and after intravenous administration of heparin. Ankle brachial pressure index was measured and treadmill exercise ...