Spending Time in Traffic Triples Risk of Heart Attack
Transient exposure to traffic may trigger heart attacks in susceptible people. The risk of a heart attack triples within an hour of being exposed to traffic pollution, whether traveling in cars, on mass transit, or by bicycle, according to a study by German researchers.
The researchers interviewed close to 700 heart attack survivors around Augsburg, Germany regarding their activities in the four days preceding the attack. The design of the study allowed for the control of other risk factors such as exercise, anger, and drug use.
A large percent of the heart attacks occurred within an hour of being in traffic. The fact that similar risks were observed for transit riders as for drivers minimizes the likelihood that the effect is entirely attributable to the stress of driving.
Researchers conclude that “patients who are at risk for acute coronary events are likely to profit from recent efforts to improve the air quality in urban areas with the use of cleaner vehicles and improved city planning.”
In an accompanying editorial, cardiologist Dr. Peter H. Stone of Harvard Medical School writes: “Decades of epidemiologic evidence underscore the cardiovascular morbidity and mortality related to air pollution. The proinflammatory, proatherosclerotic, and prothrombotic effects of particulate air pollution are compelling. As both epidemiologic and now mechanistic evidence mounts, there is greater urgency to accelerate our efforts to reduce particulate air pollution and to improve cardiovascular health.”
Peters A, von Klot S, Heier M, Trentinaglia I, Hörmann A, Wichmann HE, Löwel H. Exposure to Traffic and the Onset of Myocardial Infarction. N Engl J Med 2004;351:1721-30.
Stone PH. Triggering Myocardial Infarction. N Engl J Med 2004;351:1716-1718.
The New England Journal of Medicine [www.nejm.org] offers the abstract online.
For an extract of the editorial click here.
