Another road hazard: risk of heart attack

People caught in traffic are three times more likely to suffer a heart attack within the hour than those who aren’t tied up on the road, researchers have concluded.

The study of hundreds of heart attacks in southern Germany established that nearly one in 12 attacks was linked to traffic. Traffic jams were more likely to take a toll on women and people 60 and older. Whether the excess heart attacks were a result of stress or exposure to vehicle pollution isn’t known.

Because air pollution is known to increase the probability of a heart attack, the researchers said, people at risk for heart problems could profit from efforts to improve air quality.

The study was based on interviews with 691 volunteers who survived a heart attack from 1999 to 2001. The patients were asked to outline their activities during the four days before their attacks.

Traffic posed a risk regardless of the mode of transportation. Heart attacks were 2.6 times more common for people stuck in cars, 3.1 times higher for people stalled in traffic while taking public transportation, and 3.9 times greater for those jammed up while on a bicycle.

The study was published in Thursday’s issue of the New England Journal of Medicine.