Low molecular weight heparins in acute coronary syndrome

Background: Low molecular weight heparins (LMWH) have gained an increased r ole in the treatment of acute coronary syndrome within the last years. Comp ared to unfractionated heparins LMWH are user-friendly (high bioavailabilit y after subcutaneous application, no needed routine control of plasma effic acy). Results of Studies: International trials have demonstrated a comparable (da lteparin, nadroparin) or even higher (enoxaparin) efficacy of LMWH compared to unfractionated heparin in the treatment of patients with unstable angin a or non-O; wave infarction. The use of LMWH has thereby been accompanied b y a low rate of side effects. Enoxaparin appears to have the highest effica cy compared with other LMWH in the acute phase of disease, but confirming " head-to head" studies with different LMWH are lacking. A significant higher efficacy of a prolonged treatment with LMWH compared to placebo has been s hown in one study (FRISC-2) in unstable patients who were not treated by co ronary intervention in the early phase of disease. This lasted for about 60 days but was associated with a higher risk of bleeding. Future Aspects: Currently, prospective clinical trials investigate the effi cacy of combined use of LMWH with thrombolytics, GPIIb/IIIa blockers and th e optimal dosage of LMWH during coronary interventions.