[Use of heparin in unstable angina and non-Q-wave infarction]

The limitations of conventional treatment by non-fractionated heparin (NFH) in unstable angina and non-Q wave infarction with a serious adverse event rate (infarction and/or death) of 7 to 9% at 30 days have led to research in the use of low molecular weight heparin (LMWH). In 1995, Gurfinkel et al reported the superiority of the association aspirin-LMWH (Nadroparine) over a more classical treatment with aspirin alone or the association of aspirin-NFH in unstable angina and non-Q wave infarction. In 1996, the FRISC trial confirmed the value of LMWH (Dalteparine). However, this trial compared the LMWH with placebo. In 1997, the FRIC trial showed that dalteparine was equivalent to NFH. However, the ESSENCE and TIMI 11B trials reported the superiority of LMWH (Enoxaparine) over NFH in unstable angina and non-Q wave infarction. Compared with NFH, a significant 20% reduction in the composite criterion (death-non-fatal infarction) was observed with enoxaparine from the 2nd day up to day 43, without an increase in serious haemorrhagic complications. More recently, FRISC II showed the value and indicated the duration of treatment of LMWH, dalteparine, with respect to the chosen "invasive" or "non-invasive" strategies of revascularisation. The subcutaneous administration, absence of biological controls, the predictability of the anticoagulation and the better tolerance of the LMWH are powerful arguments in favour of their use in unstable angina and non-Q wave infarction. Thus, the LMWH have taken their place in the treatment of unstable coronary disease where the therapeutic arsenal is in constant evolution.