Myocardial Ischaemia After Exposure to Diesel Exhaust (MIDAS)
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Purpose
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
| Condition | Intervention |
|---|---|
|
Coronary Heart Disease |
Other: CT/PET Myocardial Perfusion Imaging using O-15 water Other: Coronary blood flow measured by doppler echocardiography |
| Study Type: | Interventional |
| Study Design: | Allocation: Randomized Intervention Model: Crossover Assignment Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor) Primary Purpose: Basic Science |
| Official Title: | Myocardial Ischaemia After Exposure to Diesel Exhaust |
- Myocardial blood flow and coronary flow reserve measured by CT/PET O-15 imaging [ Time Frame: Immediately following exposure ] [ Designated as safety issue: No ]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
- Coronary flow reserve determined using doppler echocardiography [ Time Frame: 1 hour following exposure ] [ Designated as safety issue: No ]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
- Ultra-sensitive cardiac troponin-I [ Time Frame: Before, 2 and 24 hours following exposure ] [ Designated as safety issue: No ]Blood samples will be obtained for measurement of cardiac troponin-I
- ST segment deviation on continuous 12-lead electrocardiography [ Time Frame: During and for the 24 hours aftet exposure ] [ Designated as safety issue: No ]A 12-lead electrocardiogram will be continuously recorded using Holter ECG monitor
| Estimated Enrollment: | 24 |
| Study Start Date: | October 2012 |
| Estimated Study Completion Date: | September 2013 |
| Estimated Primary Completion Date: | January 2013 (Final data collection date for primary outcome measure) |
| Arms | Assigned Interventions |
|---|---|
|
Placebo Comparator: Filtered Air Exposure
Subjects will be exposed to filtered air for 1 hour during intermittent exercise in a purpose-built exposure facility
|
Other: CT/PET Myocardial Perfusion Imaging using O-15 water Other: Coronary blood flow measured by doppler echocardiography |
|
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
|
Other: CT/PET Myocardial Perfusion Imaging using O-15 water Other: Coronary blood flow measured by doppler echocardiography |
Eligibility| Ages Eligible for Study: | 18 Years to 60 Years |
| Genders Eligible for Study: | Male |
| Accepts Healthy Volunteers: | Yes |
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
Contacts and Locations| Contact: Jeremy P Langrish, MB BCh MRCP | +441312426428 | jeremy.langrish@ed.ac.uk |
| United Kingdom | |
| University of Edinburgh / NHS Lothian | Not yet recruiting |
| Edinburgh, United Kingdom, EH16 4SB | |
| Principal Investigator: Jeremy P Langrish, MB BCh MRCP | |
| Sub-Investigator: Nicholas L Mills, PhD MRCP | |
| Sub-Investigator: Anoop Shah, MB BCh MRCP | |
| Study Chair: | David E Newby, PhD FRCP | University of Edinburgh |
| Principal Investigator: | Jeremy P Langrish, MB BCh MRCP | University of Edinburgh |
More Information
Publications:
| Responsible Party: | University of Edinburgh |
| ClinicalTrials.gov Identifier: | NCT01661582 History of Changes |
| Other Study ID Numbers: | MIDAS |
| Study First Received: | August 7, 2012 |
| Last Updated: | August 7, 2012 |
| Health Authority: | United Kingdom: Research Ethics Committee |
Keywords provided by University of Edinburgh:
|
Air Pollution Myocardial Ischaemia Coronary Blood Flow |
Diesel Exhaust Troponin Electrocardiography |
Additional relevant MeSH terms:
|
Myocardial Ischemia Coronary Artery Disease Coronary Disease Heart Diseases Ischemia |
Cardiovascular Diseases Vascular Diseases Arteriosclerosis Arterial Occlusive Diseases Pathologic Processes |
ClinicalTrials.gov processed this record on May 16, 2013