Heart patients should avoid traffic pollution
15 years, 7 months ago
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Posted on Sep 11, 2008, 6 a.m.
By Rich Hurd
People who have recently had a heart attack should try to avoid traffic pollution for at least a month after they are discharged from hospital, suggest results of a recent study which found that air pollution may adversely affect heart function.
People who have recently had a heart attack should try to avoid traffic pollution for at least a month after they are discharged from hospital, suggest results of a recent study which found that air pollution may adversely affect heart function.
Researchers fitted 48 cardiac patients living in the Boston area with monitors that measured ST-segment level changes every 30 minutes, 24-hours a day, for 1 year. All patients had heart disease, had suffered from heart attack or had unstable angina, and had all undergone percutaneous coronary intervention. One quarter of participants had diabetes. While the participants wore the monitors, two types of pollutants – atmospheric fine particle matter (PM) and black carbon (BC), were monitored at a site an average of 10.9 miles from the participants' homes. The researchers then analysed the association between half-hourly ST segment levels and ambient pollution levels.
Results showed that an increase in ambient pollution was predictive of ST-segment depression – meaning that the heart was receiving an inadequate supply of oxygen. The effects of pollution were greatest within the first month after hospitalization, for participants who had been hospitalized for a heart attack, and for participants with diabetes.
“Further research is needed to evaluate whether the pollution-related ST-segment depression that we see is related to increased heart muscle inflammation, reduced oxygen flow, oxidative stress, or increased risk of arrhythmias,” said Diane R. Gold, M.D., M.P.H., the study's senior author, in a news release issued by the American Heart Association. “We think that our findings, which are definitely subclinical, may represent a process that increases clinical risk for people with symptomatic coronary artery disease.”
Chuang KJ, Coull BA, Zanobetti A, Suh H, Schwartz J, Stone PH, Litonjua A, Speizer FE, Gold DR. Particulate Air Pollution as a Risk Factor for ST-Segment Depression in Patients With Coronary Artery Disease. Circulation. 2008 Sep 8. [Epub ahead of print]
