Heavy traffic boosts heart attack risk

People in heavy traffic are three times more likely to suffer a heart attack within an hour, says a new study.

"Heavy traffic increases the risk of heart attack whether you drive, take the bus, or bicycle, within one hour. Air pollution from car fumes is the likely culprit," said Annette Peters, PhD, and colleagues at the Institute of Epidemiology, Helmholtz Center, Munich, Germany.

The researchers interviewed 1,454 people who survived heart attacks. In the hour before their heart attack, many of the survivors had been in heavy traffic.

Analysis of the data showed that these heart-attack-vulnerable people were 3.2 times more likely to suffer a heart attack if they'd been in heavy traffic in the previous hour.

"One potential factor could be the exhaust and air pollution coming from other cars," Peters said. "But we can't exclude the synergy between stress and air pollution that could tip the balance."

Making it less likely that stress was involved was the fact that patients didn't have to be driving; the risk was the same whether they were driving or taking the bus.