• The combination of non-fatal myocardial infarction, non-fatal stroke or vascular death, excluding confirmed cerebral haemorrhage
  

• Serious vascular event in various prognostic subgroups
  
• Cerebral haemorrhage
  

The role of antiplatelet therapy (chiefly aspirin) for the secondary prevention of heart attacks and strokes is firmly established for many high-risk people with diagnosed arterial disease, and the proportional reductions in these cardiovascular events appear to be about one quarter, whether or not such patients have diabetes. But, most younger and middle-aged people with diabetes do not have manifest arterial disease - although they are still at significant cardiovascular risk - and yet few trials have tested aspirin in such individuals. As a result, there is substantial uncertainty about the role of aspirin for the prevention of heart attacks and strokes among apparently healthy people with diabetes, and only a small minority receives it.

There is consistent evidence from observational studies of lower rates of cardiovascular disease (particularly cardiac and sudden death) in people with higher intakes, or higher blood levels, of fish oils (omega-3 fatty acids). Trials in people who have survived a heart attack have shown modest, but potentially worthwhile, reductions in coronary events. There have been, however, no large-scale trials of the use of fish oils for the prevention of vascular events in people without diagnosed arterial disease.

If ASCEND can reliably demonstrate that aspirin and/or fish oils safely reduce the risk of cardiovascular events and deaths in people with diabetes who do not have pre-existing arterial disease, then this would be relevant to some tens of millions of people world-wide (who are currently not receiving such therapy) and might save tens of thousands of lives each year.

Inclusion Criteria:

• Males or females with type 1 or type 2 diabetes mellitus.
• Aged ≥ 40 years.
• No previous history of vascular disease.
• No clear contra-indication to aspirin.
• No other predominant life-threatening medical problem.

Exclusion Criteria:

• Definite history of myocardial infarction, stroke or arterial revascularisation procedure.
• Currently prescribed aspirin, warfarin or any other blood thinning medication.