In addition to its
anticoagulant effects,
heparin is known to have antiproliferative effects on vascular smooth muscle cells.
Ardeparin is a partially depolymerized (
low molecular weight) heparin that has a longer half-life than
unfractionated heparin. Following successful coronary balloon angioplasty, 565 patients were randomized to treatment with twice-daily subcutaneous
ardeparin 50 anti-Xa U/kg (low dose) or 100 anti Xa U/kg
body weight (high dose), or placebo for 3 months. Follow-up angiography was performed in 415 patients at 4 months, or earlier if clinically indicated. Additionally, patients underwent treadmill exercise electrocardiography at 2 weeks and 4 months. This study was designed to test the hypothesis that 3 months of subcutaneous dosing of
ardeparin would reduce angiographic restenosis after coronary balloon angioplasty.
Ardeparin had no effect on the incidence of angiographic restenosis (prespecified definition: > or = 50%
luminal diameter narrowing plus a loss of 50% of initial gain or absolute decrease of 20% of
luminal diameter). Neither the mean
luminal diameters nor mean percent diameter
stenoses were different among the treatment groups before, after, or 4 months after balloon angioplasty. On exercise electrocardiography at 2 weeks and 4 months, patients in all treatment groups had similar exercise tolerance, incidence of angina, and frequency of ST depression. Thus,
ardeparin treatment given subcutaneously for 3 months after successful balloon angioplasty does not reduce either angiographic or clinical measures of restenosis.