Aspirin for primary prevention of coronary heart disease

To determine the effects, both harmful and beneficial of aspirin in the primary prevention of coronary heart disease.

Primary questions

Does aspirin prevent fatal and non-fatal CHD in people without symptomatic vascular disease?
Does aspirin reduce all-cause and cardiovascular mortality?

Secondary questions
Are the effects of aspirin, be they harmful or beneficial, affected by underlying risk of CHD?
Do the major adverse effects of Aspirin ever outweigh its benefit and is this balance affected by underlying CHD risk?

This is a protocol.