Christopher Heeschen and Christian Hamm, of the department of cardiovascular medicine at Stanford University, California, also writing in The Lancet, said there are three possible reasons for the lack of benefit of sibrafiban.

BBC: Aspirin 'as good as heart drug'

Also, the safe and effective levels of drugs such as sibrafiban are not yet known, and the patients included in the study may not have been high risk, so the drug's effect would be small, they added.

BBC: Aspirin 'as good as heart drug'

Publishing their results in The Lancet medical journal, the scientific team led by Dr Kristin Newby at the Duke Clinical Research Institute of North Carolina, said sibrafiban "showed no additional benefit over aspirin" in preventing cardiac arrest.

BBC: Aspirin 'as good as heart drug'