By Andrew M. Seaman
NEW YORK (Reuters Health) - Despite expert guidelines advising against intense sports activity for people with implanted heart defibrillators, a new study suggests that some can compete without serious consequences.
Researchers followed 372 athletes with defibrillators for about two and a half years and found that none died while running, skiing or playing sports like basketball and soccer.
That doesn't mean none were shocked by their device - which restores normal heart rhythm - during competition or practice, but shocks were no more likely during sports than during other leisure or work activities.
Dr. Rachel Lampert, the study's lead author from the Yale School of Medicine in New Haven, Connecticut, said the findings don't give every person with a defibrillator license to play sports, but they can help doctors determine whether their patients can start competing again.
"I think our data will help physicians help their patients return to play," she told Reuters Health.
Implantable cardioverter-defibrillators, or ICDs, resemble pacemakers, but are somewhat more complex. They monitor the heart constantly and are programmed to send electric shocks when they detect dangerous disturbances in the heart's rhythm.
An estimated 100,000 of the devices are implanted each year in the United States, to treat a range of conditions that can lead the heart to beat erratically or arrest suddenly.
Currently, the American College of Cardiology (ACC) and the European Society for Cardiology advise against people with ICDs playing anything more strenuous than golf and bowling, according to the researchers.
Lampert said the primary concerns are that ICDs won't work during competition and that failure could cause deaths, or that athletes would be injured by the strong shock in the midst of play, and that the device could be damaged during play.
Past research has found, however, that many people with ICDs take part in sports with no known reports of serious injuries or deaths.
For the new study, published in the journal Circulation, the researchers recruited American and European athletes with ICDs between the ages of 10 and 60 years old starting in 2006.
Among the 372 athletes, running, basketball and soccer were the most popular sports. But about a quarter of participants also took part in high-risk sports, such as skiing and snowboarding.
The researchers checked in with each participant every six months until January 2012. On average, each athlete was followed for about two and a half years.
No deaths or shock-related injuries to participants were reported during the study.
About 20 percent of the athletes received shocks from their ICDs at any time during the follow-up period. And about 10 percent of athletes were shocked during competition or practice, but about two thirds of those returned to play, said Lampert.
The proportion of people whose devices showed damage to the electrical leads was about the same as the normal failure rate of those components among all ICD users.
Dr. Barry J. Maron, one of the study's co-authors who also led the writing of ACC's statement on sports and ICDs, said shocks are not minor events and any decision about ICDs and sports should take the risk of shocks into account.
"The morbidity risk is not necessarily low because there was a large number or percentage of shocks. Those are important events and must be taken into consideration in any decision making," Maron, director of the Hypertrophic Cardiomyopathy Center at Minneapolis Heart Institute Foundation, told Reuters Health.
Lampert said more research is needed on how doctors should determine which of their patients can safely start to play sports or begin exercising, because her group's study only included people with ICDs who were already playing sports when they were enrolled.
"The bottom line is you need to take each person's individual situation into account," she said.
"It's a decision that requires a lot of prudence and consideration from the physicians, but (the current advice) isn't a dictum or tells you what to do. In other words, physician judgment is still in play," Maron said.
SOURCE: http://bit.ly/18bD9af Circulation, online May 20, 2013.