Heparins reduce the number of heart attacks after acute coronary syndromes

Clinical question: 
How effective are heparins in the treatment of patients with acute coronary syndromes (ACS)?
Bottom line: 
Compared to placebo, heparins reduce the number of heart attacks (NNT* 33) but cause more minor bleeding (NNH* 17) after ACS. The risks of mortality, revascularisation, recurrent angina, major bleeding and thrombocytopenia were similar in both groups. *NNT = number needed to treat to benefit one individual. *NNH = number needed to treat to cause harm in one individual.
Caveat: 
Parenteral unfractionated heparin (UFH) or low molecular weight heparin (LMWH) was given in addition to standard therapy with aspirin.
Context: 
Acute coronary syndromes include unstable angina and non-ST segment myocardial infarction. The use of UFH and LMWH heparin were evaluated in these trials, and were given within 24 to 72 hours of the onset of symptoms for a 2 to 8 day period.
Review CD#: 
CD003462
PEARLS No: 
89
Date: 
July, 2008
Authored by: 
Brian R McAvoy