LOW-MOLECULAR-WEIGHT HEPARIN IN PREVENTION OF RESTENOSIS AFTER ANGIOPLASTY - RESULTS OF ENOXAPARIN RESTENOSIS (ERA) TRIAL

Background Heparin, an anticoagulant, possesses antiproliferative effe cts and has been shown to reduce neointimal proliferation and restenos is following vascular injury in experimental studies. Methods and Resu lts The primary aim of this double-blind multicenter study was to dete rmine if 40 mg Enoxaparin, a low molecular weight heparin, administere d subcutaneously once daily for 1 month after successful angioplasty w ould reduce the incidence of restenosis. Four hundred fifty-eight pati ents were randomized at nine clinical centers (231 to placebo and 227 to Enoxaparin). The primary end point was angiographic or clinical res tenosis. Angiographic restenosis was defined as a loss of 50% of the i nitial gain as measured by quantitative coronary angiography (QCA) at a core laboratory. In the absence of QCA, clinical evidence of resteno sis was defined as death, myocardial infarction, repeat revascularizat ion, or worsening angina. Using the intention-to-treat analysis for al l patients, restenosis occurred in 51% of the placebo group and 52% of the Enoxaparin group (relative risk, 1.07, P=.625). Likewise, no diff erence in restenosis was evident when the change in minimal lumen diam eter or other angiographic definitions of restenosis were used. Advers e clinical events were infrequent and did not differ between the group s with the exception of minor bleeding complications, which were more common in the Enoxaparin group. Conclusions Enoxaparin (40 mg/d SC for 1 month) following successful angioplasty did not reduce the incidenc e of angiographic restenosis or the occurrence of clinical events over 6 months. The treatment was well tolerated, although in-hospital mino r bleeding was more common with active treatment.