• The primary end point was a composite of
  
• nonfatal myocardial infarction,
  
• fatal myocardial infarction,
  
• nonfatal stroke,
  
• fatal stroke, and
  
• sudden death attributed to coronary heart disease.
  

• Individual components of the primary end point, i.e.
  
• Nonfatal myocardial infarction
  
• Fatal myocardial infarction
  
• Nonfatal stroke
  
• Fatal stroke
  
• In addition the following secondary outcomes:
  
• Unstable angina pectoris requiring hospitalization
  
• Percutaneous coronary revascularization
  
• Coronary-artery bypass grafting
  
• Death from any cause
  
• Cancer
  
• Pulmonary embolus
  
• Transitoric ischemic attack
  
• Surgery for abdominal aortic aneurysm
  
• Plasma homocysteine levels
  
• Plasma levels of B vitamins
  

Observational studies have demonstrated that elevated levels of plasma total homocysteine is a risk factor for cardiovascular disease. The purpose of this trial is to evaluate the efficacy of homocysteine lowering treatment with B vitamins for secondary prevention in patients who have experienced an acute myocardial infarction.

This controlled, double-blind, multi-centre trial will include 3750 men and women aged 30-85 who have experienced an acute myocardial infarction within 7 days prior to randomization. Participants will be randomized, in a two-by-two factorial design, to receive one of the following four treatments: A, folic acid 0.8 mg plus vitamin B12 0.4 mg and vitamin B6 40 mg per day; B, folic acid 0.8 mg plus vitamin B12 0.4 mg per day; C, vitamin B6 40 mg per day; D, placebo.

The primary end point during 3.5 years of follow-up is a composite of recurrent myocardial infarction and stroke and sudden death attributed to coronary artery disease.