• Symptoms of angina pectoris - assessed by symptom diary and reliever medication usage [ Time Frame: Throughout study period ] [ Designated as safety issue: No ]
  

• Myocardial ischaemic burden - assessed using 12-lead continuous Holter ECG monitoring [ Time Frame: Throughout study period ] [ Designated as safety issue: No ]
  
• Time to 1mm ST segment depression during standard BRUCE exercise stress testing [ Time Frame: At the end of the study period ] [ Designated as safety issue: No ]
  
• Total exercise capacity - measured using GPS tracking of activity completed [ Time Frame: Throughout study period ] [ Designated as safety issue: No ]
  
• Exercise capacity - determined by standard BRUCE exercise stress testing [ Time Frame: Immediately after study period ] [ Designated as safety issue: No ]
  
• Ambulatory blood pressure [ Time Frame: Throughout study period ] [ Designated as safety issue: No ]
  
• Biochemical evidence of myocardial ischaemia - highly sensitive troponin, ischaemically modified albumin and fatty acid binding protein [ Time Frame: Before and after study period ] [ Designated as safety issue: No ]
  

Exposure to air pollution has been shown in epidemiological studies to be closely linked to cardiovascular morbidity and mortality. The exact components of air pollution that underlie the cardiovascular effects are not yet known, but combustion-derived particulate matter is suspected to be the major cause. In controlled exposure studies, we have recently demonstrated that exposure to diesel exhaust causes increased myocardial ischaemia with exercise in patients with asymptomatic coronary artery disease. The mechanism behind this effect is not yet understood, but we have shown that diesel exhaust exposure causes an acute impairment of two important and highly relevant aspects of vascular tone: vasomotor tone and endogenous fibrinolysis. In this study we propose to investigate the effects of exposure to ambient levels of air pollution on patients with stable, symptomatic angina pectoris, during their daily lives.

Patients with stable angina pectoris and documented coronary artery disease

Inclusion Criteria:

• Documented coronary artery disease
• Symptoms of stable angina pectoris
• Positive BRUCE exercise stress test between 3 and 13 minutes

Exclusion Criteria:

• History of arrhythmia
• Severe 3 vessel coronary disease or left main stem stenosis that has not been revascularised
• Resting conduction abnormality
• Digoxin therapy
• Uncontrolled hypertension
• Renal or hepatic failure
• Unstable symptoms or acute coronary syndrome within 3 months