Antithrombotic therapy in the catheterization laboratory : interim analysis of the NICE trials

Low-molecular-weight heparins (LMWHs) offer potential advantages over unfractionated heparin (UFH) during coronary interventions. By removing the need for coagulation monitoring, LMWHs could simplify the procedure while potentially also offering greater efficacy. The increasing use of LMWHs as primary therapy for acute coronary syndromes also demands that safety and efficacy data during cardiac catheterization are collected for these agents. Preliminary data from two open-label studies of the LMWH enoxaparin during coronary interventions indicate that enoxaparin can safely be used without monitoring. The rates of major haemorrhage and groin complications were very low and compared favourably with results from other trials. During elective percutaneous transluminal coronary angioplasty, a pilot study comparing enoxaparin with UFH found that the antithrombotic effect of enoxaparin was more consistent than that of UFH. Whilst 30% of patients treated with UFH required additional bolus injections to reach the target range for activated clotting time, a single bolus of enoxaparin was sufficient in all cases. Since suboptimal anticoagulation is known to be associated with higher event rates, enoxaparin could offer a means of ensuring that all patients undergo coronary interventions with effective antithrombotic cover.