This article seems to confuse triggers with long-term contributing factors. Traffic might just cause small peaks in stress that trigger only heart attacks that would have otherwise happened days later. To recommend staying out of traffic, research would need to show that people regularly in traffic are more likely to have heart attacks or have them significantly earlier than people who don’t spend time in traffic.

Paul Ramsey
Tucson, Ariz
.

Carbon monoxide may be the primary reason for heart attacks after being in traffic. As carbon monoxide replaces oxygen in the blood, it may push people with constricted blood flow to the heart into a heart attack.

Jim Beregi
Port Orford, Ore
.