• Composite event of cerebro/cardiovascular (CV) death, nonfatal cerebral stroke (of any cause) and nonfatal myocardial infarction (MI)
  

• CV death
  
• Non CV death
  
• Nonfatal cerebral stroke
  
• Nonfatal MI
  
• Angina pectoris
  
• Transient ischemic attack
  
• Arteriosclerotic disease requiring surgery or intervention
  
• Extracranial bleeding requiring transfusion or admission
  
• Severe side-effects that lead to interruption of the study medication.
  

Cerebro/cardiovascular (CV) death accounts for approximately 30% of total deaths in Japan and therefore it is important to establish a preventive treatment for CV events from the point of public health. The guidelines proposed by a joint study group centering on the Japanese Circulation Society, recommend administration of aspirin to patients with multiple risk factors for primary prevention of arteriosclerotic diseases. In addition, the 2002 AHA guidelines recommend use of aspirin in patients with a 10% or higher 10-year risk of CV events. However, these descriptions are founded on randomized, comparative study results and epidemiological data obtained outside Japan, while no epidemiological data are available in Japan that would allow prediction and selection of patients who could benefit from primary prevention with aspirin. Although the benefit of aspirin for secondary prevention has been proven in Japanese patients, the benefits of primary prevention are still controversial.

JPPP is a multicenter, open-label, centrally randomized, controlled trial. In total, 10,000 elderly patients with one or more CV risk factors (age 60–85 years combined with hypertension, hyperlipidemia, and/or diabetes) will be assigned to enteric-coated aspirin (100mg/day) or control. The primary endpoint is composite event of CV death, nonfatal stroke (of any cause) and nonfatal myocardial infarction.