Myocardial Ischaemia After Exposure to Diesel Exhaust (MIDAS)
Exposure to particulate air pollution is associated with increases in cardiovascular mortality and morbidity. The pathophysiological mechanisms underlying this observation are emerging, and exposure to particulate air pollution has been shown to result in increases in blood pressure and arterial tone, impaired vascular function and an increased tendency for blood to clot as well as an increase in atherosclerotic plaque burden. Recent evidence from panel studies and controlled exposure studies have suggested an increase in myocardial ischaemia (a reduction in blood flow to the heart) following exposure. In this study we aim to investigate directly myocardial (heart) blood flow following exposure to diesel exhaust (as a model of urban air pollution) using CT/PET myocardial perfusion imaging in male patients with stable coronary disease and healthy male controls. We hypothesize that following exposure to dilute diesel exhaust:
- Myocardial blood flow will be reduced
- Coronary flow reserve will be impaired
- The magnitude of impairment will be higher in patients with coronary disease as compared to healthy controls
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Contact
Study Contact
- Name: Jeremy P Langrish, MB BCh MRCP
- Phone Number: +441312426428
- Email: jeremy.langrish@ed.ac.uk
Study Locations
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Edinburgh, United Kingdom, EH16 4SB
- University of Edinburgh / NHS Lothian
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Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Description
Inclusion Criteria:
- Healthy volunteers will be taking no regular medication, have a normal electrocardiogram and exercise stress test
- Patients with a previous history of myocardial infarction or successful coronary revascularization (PTCA or coronary artery bypass grafting) but without symptoms of angina pectoris will be recruited
Exclusion Criteria:
- Healthy volunteers:
- Regular medication
- Abnormal 12-lead electrocardiogram
- Abnormal exercise stress test
- Patients with coronary disease
- Acute coronary syndrome within past 3 months
- Impaired left ventricular function
- Significant valvular heart disease
- Left ventricular hypertrophy
- Resting conduction defect
- Digoxin use
- Renal impairment (eGFR <60 mL/min)
- Hepatic impairment
- Asthma
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Basic Science
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Quadruple
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
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Placebo Comparator: Filtered Air Exposure
Subjects will be exposed to filtered air for 1 hour during intermittent exercise in a purpose-built exposure facility
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Experimental: Dilute Diesel Exhaust Exposure
Subjects will be exposed to dilute diesel exhaust (~300 mcg/m3) for 1 hour during intermittent exercise in a purpose-built exposure facility
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What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Myocardial blood flow and coronary flow reserve measured by CT/PET O-15 imaging
Time Frame: Immediately following exposure
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Myocardial blood flow will be measured at rest and at peak adenosine stress using CT/PET O-15 myocardial perfusion imaging immediately following exposure to diesel exhaust and filtered air
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Immediately following exposure
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Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
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Coronary flow reserve determined using doppler echocardiography
Time Frame: 1 hour following exposure
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Coronary blood flow will be determined in the left anterior descending coronary artery using doppler echocardiography at rest and at peak adenosine stress 1 hour following exposure to diesel exhaust and filtered air
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1 hour following exposure
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Ultra-sensitive cardiac troponin-I
Time Frame: Before, 2 and 24 hours following exposure
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Blood samples will be obtained for measurement of cardiac troponin-I
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Before, 2 and 24 hours following exposure
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ST segment deviation on continuous 12-lead electrocardiography
Time Frame: During and for the 24 hours aftet exposure
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A 12-lead electrocardiogram will be continuously recorded using Holter ECG monitor
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During and for the 24 hours aftet exposure
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Collaborators and Investigators
Sponsor
Sponsor
Collaborators
Collaborators
Investigators
Investigators
- Principal Investigator: Jeremy P Langrish, MB BCh MRCP, University of Edinburgh
- Study Chair: David E Newby, PhD FRCP, University of Edinburgh
Publications and helpful links
General Publications
- Mills NL, Tornqvist H, Gonzalez MC, Vink E, Robinson SD, Soderberg S, Boon NA, Donaldson K, Sandstrom T, Blomberg A, Newby DE. Ischemic and thrombotic effects of dilute diesel-exhaust inhalation in men with coronary heart disease. N Engl J Med. 2007 Sep 13;357(11):1075-82. doi: 10.1056/NEJMoa066314.
- Langrish JP, Watts SJ, Hunter AJ, Shah AS, Bosson JA, Unosson J, Barath S, Lundback M, Cassee FR, Donaldson K, Sandstrom T, Blomberg A, Newby DE, Mills NL. Controlled exposures to air pollutants and risk of cardiac arrhythmia. Environ Health Perspect. 2014 Jul;122(7):747-53. doi: 10.1289/ehp.1307337. Epub 2014 Mar 25.
Study record dates
Study Major Dates
Study Start (Actual)
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Estimated)
First Posted
Study Record Updates
Last Update Posted (Actual)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
Other Study ID Numbers
- MIDAS
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