Reducing the Pro-ischaemic Effects of Air Pollution Exposure Using a Simple Face Mask

This study has been completed.
Sponsor:
Collaborator:
Cardiovascular Institute & Fuwai Hospital
Information provided by:
University of Edinburgh
ClinicalTrials.gov Identifier:
NCT00809653
First received: December 15, 2008
Last updated: March 30, 2010
Last verified: May 2009
  Purpose

Air pollution is a major cause of cardiorespiratory 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. Epidemiological studies have shown that exposure to air pollution causes exacerbation of existing cardiorespiratory conditions leading to increased hospital admissions and death. The investigators have recently conducted a series of controlled exposure studies to urban particulate matter and diesel exhaust in healthy volunteers and patients with coronary heart disease. The investigators found that controlled exposure to dilute diesel exhaust in patients with prior myocardial infarction induced asymptomatic myocardial ischaemia with an increase in electrocardiographic measures of myocardial ischaemia. Whilst important, further questions remain: (i) does air pollution exposure exacerbate ischaemia and reduce exercise tolerance in patients with symptomatic angina pectoris, (ii) do "real world" exposures as encountered in the urban environment of major cities have similar effects, and (iii) can a simple face mask intervention to reduce exposure to particulate air pollution improve health outcomes in patients with coronary heart disease?


Condition Intervention
Angina Pectoris
Coronary Heart Disease
Blood Pressure
Heart Rate Variability
Device: No Face Mask
Device: Face Mask

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Basic Science
Official Title: Reducing the Pro-ischaemic Effects of Ambient Particulate Air Pollution in Patients With Coronary Heart Disease Using a Simple Face Mask Intervention

Resource links provided by NLM:


Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • Myocardial ischaemic burden determined using continuous electrographic monitoring [ Time Frame: During 2 hour walk and subsequent 24 hour period ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Symptoms of angina pectoris assessed by patient diary and GTN use [ Time Frame: During 2 hour walk and subsequent 24 hour period ] [ Designated as safety issue: No ]
  • Biochemical markers of myocardial ischaemia [ Time Frame: After 2 hour city centre walk ] [ Designated as safety issue: No ]
  • Systemic inflammatory markers [ Time Frame: After 2 hour city centre walk ] [ Designated as safety issue: No ]
  • Blood pressure [ Time Frame: During 2 hour walk and for subsequent 24 hours ] [ Designated as safety issue: No ]
  • Heart rate and heart rate variability [ Time Frame: During 2 hour walk and subsequent 24 hour period ] [ Designated as safety issue: No ]
  • Personal exposure to air pollutants [ Time Frame: During 2 hour walk ] [ Designated as safety issue: No ]
  • Exercise capacity, time to symptoms and time to 1mm ST segment depression on standard treadmill exercise testing [ Time Frame: Immediately after 2 hour city centre walk ] [ Designated as safety issue: No ]

Estimated Enrollment: 100
Study Start Date: January 2009
Study Completion Date: May 2009
Primary Completion Date: May 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Visit 1
2 hour walk in city centre location in Beijing China
Device: No Face Mask
Subjects will not wear a face mask to reduce their personal air pollution exposure
Experimental: Visit 2
2 hour walk in city centre location in Beijing China
Device: Face Mask
Subjects will be asked to wear a simple face mask to reduce personal exposure to particulate air pollution. Subjects will be asked to wear the mask for 24 hours prior to the study day and the 24 hours of the study day. They will be instructed to wear the mask at all times when outdoors and as much as possible when indoors.
Other Name: 3M Dust Respirator 8812

Detailed Description:

100 patients with stable angina pectoris will be recruited from the HPS-THRIVE cohort or from the cardiology outpatient department at the Fuwai Hospital in Beijing. Patients will attend the department first thing in the morning on two occasions, separated by at least 1 week. All subjects will be fitted with a 12-lead Holter monitor and 24-hour ambulatory blood pressure monitor. They will be issued with a diary to record their activities and symptoms.

Patients will be randomised to wear a simple facemask for one of their visits (3M Dust Respirator 8812). When randomised to wear a mask, subjects will be asked to wear the mask as much as possible in the 24 hours prior to the study day and for the 24 hours of the study day (48 hours in total). Subjects will be instructed to wear the mask at all times when outdoors, and as much as possible when indoors.

On both visits, patients will be asked to walk along a prespecified route for 2 hours in a city centre location in Beijing. During this period patients will walk at their own pace for 15 mins and rest for 5 mins for a total of 120 mins (6 cycles). After the walk, subjects will return to the department and the pollution equipment switched off. A formal BRUCE protocol exercise stress test will be performed as soon as possible after finishing the 2-hour walk, and blood tests will be taken just prior to the exercise stress test (10-20mls in total). Subjects will be asked to wear the ambulatory blood pressure monitor and the Holter ECG monitor for a total of 24 hours, returning the following day to have this removed. Personal exposure to air pollution will be determined during the 2 hour walk with a series of monitors contained within a small backpack.

  Eligibility

Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Stable coronary heart disease
  • Symptoms of angina pectoris
  • Evidence of coronary heart disease by angiography or by exercise stress testing

Exclusion Criteria:

  • Current smokers
  • History of arrhythmia
  • Severe 3 vessel coronary heart disease or left main stem stenosis that has not been revascularised
  • Resting conduction abnormality
  • Digoxin therapy
  • Uncontrolled hypertension
  • Renal failure
  • Hepatic failure
  • Acute coronary syndrome or unstable symptoms within 3 months
  • Significant occupation exposure to air pollution
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT00809653

Locations
China
Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Medical Union College
Beijing, China
Sponsors and Collaborators
University of Edinburgh
Cardiovascular Institute & Fuwai Hospital
Investigators
Principal Investigator: Lixin Jiang, MD Chinese Academy of Medical Sciences and Peking Medical Union College
Principal Investigator: David E Newby, PhD FRCP University of Edinburgh
  More Information

Publications:
Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Professor David E Newby, University of Edinburgh
ClinicalTrials.gov Identifier: NCT00809653     History of Changes
Other Study ID Numbers: 167/2008/Patient
Study First Received: December 15, 2008
Last Updated: March 30, 2010
Health Authority: China: Ethics Committee

Keywords provided by University of Edinburgh:
Air pollution
Face mask
Myocardial ischaemia
Heart rate variability
Angina pectoris
Coronary heart disease

Additional relevant MeSH terms:
Coronary Artery Disease
Myocardial Ischemia
Coronary Disease
Heart Diseases
Cardiovascular Diseases
Vascular Diseases
Arterial Occlusive Diseases
Angina Pectoris
Chest Pain
Pain
Signs and Symptoms
Arteriosclerosis

ClinicalTrials.gov processed this record on July 29, 2014