Road closures due to ongoing major marathons can put nearby heart attack victims at greater risk of death, according to a study in the New England Journal of Medicine.
Here are six things to know about the study and its findings.
1. A team of Harvard researchers examined 10 years of 30-day heart attack or cardiac arrest mortality rates among Americans age 65 or older during major marathons in 11 U.S. cities (Boston, Chicago, Honolulu, Houston, Los Angeles, Minneapolis, New York City, Orlando, Philadelphia, Seattle and Washington, D.C.).
2. Researchers compared death rates of those who had a cardiac event on the day of the race with those who had an event five weeks before or after the marathon, and also compared rates among people who lived near the marathon and those who lived outside of the race's road closure area.
3. They found patients who suffered a cardiac event near a marathon on race day and were admitted to a hospital were 15 percent more likely to die in 30 days than those who had a cardiac event on other days or who were far away from the race.
4. Ambulance transport times were slowed by the marathon, the research showed. It took an average of 4.4 minutes longer to transport patients during the marathon.
5. Researchers suspect road closures were the likely culprit for increased deaths and slow transport times during race days. "When it comes to treating people in the throes of a heart attack, minutes do matter. Heart muscle dies quickly during a heart attack, so current guidelines call for rapid intervention, preferably within an hour or so of diagnosing a heart attack, to salvage cardiac muscle function," Anupam Jena, MD, PhD, the study's lead author, said.
6. Dr. Jena and the other study authors called on marathon organizers to take this into account during the planning process. "The organizers of these events need to take these risks to heart when they are planning their events, and find better ways to make sure that the race's neighbors are able to receive the lifesaving care that they need quickly," Dr. Jena said.