CHARISMA

Clopidogrel and aspirin versus aspirin alone for the prevention of Atherothrombotic events - The New England Journal of Medicine - 2006

Brief Summary:

Among patients at high risk for cardiovascular events, combination aspirin plus clopidogrel did not significantly reduce the rates of MI, stroke, or death from CV causes. There was increased bleeding with combination therapy.

Reference:
http://www.ncbi.nlm.nih.gov/pubmed/16531616