Controlled Exposures to Air Pollution in Patients With Coronary Heart Disease

Coronary Heart Disease Clinical Trial

Official title:

The Effects of Air Pollution on Vascular and Endogenous Fibrinolytic Function in Patients With Coronary Heart Disease

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00437138
• Other study ID #: RG/05/003 DISARM 2
• Status: Completed
• Phase: Phase 0
• First received: February 16, 2007
• Last updated: February 16, 2007
• Start date: April 2006
• Est. completion date: June 2006

Study information

• Verified date: February 2007
• Source: University of Edinburgh
• Contact: n/a
• Is FDA regulated: No
• Health authority: Sweden: Regional Ethical Review Board
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: June 2006
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 70 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double-Blind, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Coronary Artery Disease
• Coronary Disease
• Coronary Heart Disease
• Heart Diseases
• Myocardial Ischemia

Intervention

Behavioral:
• Exposure to dilute diesel exhaust (300µg/m3) or filtered air

Locations

Country	Name	City	State
Sweden	Umeå University	Umeå	Västerbotten

Sponsors (2)

Lead Sponsor	Collaborator
University of Edinburgh	Umeå University

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Exercise induced myocardial ischemia
Primary	Vascular vasomotor function
Primary	Endogenous fibrinolytic function

External Links

•   British Heart Foundation
•   Centre for Cardiovascular Science, Edinburgh
•   Umea University, Sweden