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Controlled Exposures to Air Pollution in Patients With Coronary Heart Disease

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00437138
First Posted: February 19, 2007
Last Update Posted: February 19, 2007
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
Umeå University
Information provided by:
University of Edinburgh
  Purpose
Air pollution is a major cause of cardiovascular morbidity and mortality. The components of air pollution responsible and the mechanisms through which they might mediate these harmful effects remain only partially understood. We hypothesise that these adverse effects are mediated by combustion derived air pollutants and that even a brief exposure will effect heart and blood vessel function. We assess the effect of dilute diesel exhaust inhalation at levels encountered in urban road traffic on heart and blood vessel function in patients with stable coronary heart disease.

Condition Intervention Phase
Coronary Heart Disease Behavioral: Exposure to dilute diesel exhaust (300µg/m3) or filtered air Early Phase 1

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double
Primary Purpose: Prevention
Official Title: The Effects of Air Pollution on Vascular and Endogenous Fibrinolytic Function in Patients With Coronary Heart Disease

Resource links provided by NLM:


Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • Exercise induced myocardial ischemia
  • Vascular vasomotor function
  • Endogenous fibrinolytic function

Estimated Enrollment: 20
Study Start Date: April 2006
Estimated Study Completion Date: June 2006
Detailed Description:

Observational studies suggest that exposure to air pollution may worsen symptoms of angina and trigger acute myocardial infarction. These findings are limited by imprecision in the measurement of pollution exposure, the effect of potential confounding environmental and social factors, and the lack of mechanistic data. Controlled exposures of air pollutants can help to address these shortcomings by providing a precisely defined exposure in a regulated environment that facilitates investigation with validated biomarkers and surrogate measures of cardiovascular health. Using a carefully characterised exposure system, we have previously shown in healthy volunteers that exposure to dilute diesel exhaust causes lung inflammation, depletion of airway antioxidant defences, and impairment of vascular and fibrinolytic function. To date, there have been no controlled exposures in patients with coronary heart disease: an important population who may be particularly susceptible to the adverse cardiovascular effects of air pollution.

In a double blind randomized cross-over study, 20 patients with prior myocardial infarction will be exposed to dilute diesel exhaust (300µg/m3) or filtered air during periods of rest and moderate exercise in a controlled exposure facility. During the exposure, myocardial ischemia will be quantified by ST-segment analysis using continuous 12-lead electrocardiography. Six hours following exposure, vascular vasomotor and fibrinolytic function will be assessed by means of intra-arterial agonist infusions.

  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 70 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Previous myocardial infarction (>6 months previously) treated by primary angioplasty and stenting
  • On standard secondary preventative therapy

Exclusion Criteria:

  • Angina pectoris (Canadian Cardiovascular Society grade ≥2)
  • History of arrhythmia
  • Diabetes mellitus
  • Uncontrolled hypertension
  • Renal or hepatic failure
  • Unstable coronary disease (acute coronary syndrome or unstable symptoms within 3 months)
  • Occupational exposure to air pollution
  • Current smokers
  • Asthma
  • Inter-current illness
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00437138


Locations
Sweden
Umeå University
Umeå, Västerbotten, Sweden, 901 85
Sponsors and Collaborators
University of Edinburgh
Umeå University
Investigators
Principal Investigator: David E Newby, MD The University of Edinburgh
Principal Investigator: Thomas Sandstrom, MD Umeå University
  More Information

Additional Information:
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
ClinicalTrials.gov Identifier: NCT00437138     History of Changes
Other Study ID Numbers: RG/05/003 DISARM 2
First Submitted: February 16, 2007
First Posted: February 19, 2007
Last Update Posted: February 19, 2007
Last Verified: February 2007

Keywords provided by University of Edinburgh:
Air pollution
Myocardial ischemia
Endothelium
Fibrinolysis
Pathophysiology
Diesel exhaust

Additional relevant MeSH terms:
Heart Diseases
Coronary Disease
Coronary Artery Disease
Myocardial Ischemia
Cardiovascular Diseases
Vascular Diseases
Arteriosclerosis
Arterial Occlusive Diseases