A closer look at athletic participation for patients with ICDs

A recent paper was published in Circulation regarding the safety of sports for athletes with implantable cardioverter defibrillators. The findings set off a storm among members of the media.

Headlines in the news read: “Athletes with defibrillators don’t need to quit sports” (Forbes) and “Sports Seems OK for Many with Heart Zapping Devices” (NPR). Currently, the consensus statements from the American College of Cardiology and the European Society of Cardiology advise against vigorous sports participation in all patients with ICDs. These recommendations are based on the potential risks for failure of the ICD to defibrillate, injury as a result of syncope that could result from an exercise induced-arrhythmia or shock, or damage to the ICD from the sport. Nonetheless, these theoretical risks have not been investigated. The ICD Sports Safety registry is an observational registry to identify risks associated with sports participation for ICD patients.

This registry examined patients with ICDs who participated in organized sports, involving regular practice and regular competition, and looked at sports more vigorous than golf or bowling. They included those aged 10 to 60 years who were already participating in sports, including even high-risk sports (where brief loss of control could result in injury, such as skiing or surfing). However, enrollment in this registry was not endorsing participation in the sport. The participants were self-selected. A total of 372 persons with ICDs were included, with 44 participating in high risk sports. Sixty of the participants were engaged in varsity/junior varsity team competitions, and 72 of the athletes were participating on a national or international level. A median of 5.1 hours per week was spent participating in practice or competition. The primary endpoint of this study was tachyarrhythmic death or resuscitated tachyarrhythmia, and no one met this endpoint. A total of 77 (21 %) persons in the cohort did experience one or more shock with 40 participants receiving at least one inappropriate shock. Thirty-six (10% of the cohort) individuals experienced a shock while participating in the sport; 29 (8%) had shocks with other physical activity; and 23 (6%) had shocks during rest. Of those persons who had shocks with the sport, 21 were appropriate and it was more likely appropriate if the athlete was 20 years or older.

This observational study challenges the current guidelines and is the first to show that many athletes with ICDs can engage in sports without physical injury or failure to terminate an arrhythmia. Even though ICD shocks occurred with sports, there were no tachyarrhythmic deaths or injuries related to shocks that occurred with sports. Interestingly, although shocks occurred more often with physical activity, there was no real difference in someone getting a shock with the competitive sport/practice and shocks that occurred with other recreational activities.

This study is important because, for our patients who are athletes, participation in sport is part of their quality of life. Restricting activities can decrease quality of life just as ICD shocks can. A blanket recommendation against competitive sports may not be warranted based on these observational data.

Nevertheless, the data are still observational and do not tell us it is safe for all athletes with ICDs to continue competitive sports. Those in this registry were self-selected, and it is difficult to know if they are equally representative of all ICD participants in competitive sports. High contact sports, such as hockey, were not well-represented at all in this study. Shocks themselves were self-reported by the participants, and it isn’t clear if this would underrepresent the occurrence of ICD shock deliverance. In addition, there may be a survival bias since the participants could enroll any time after ICD implantation, with the median time being about 2 years. Certainly longer follow up is needed, and follow-up from time of implantation would be helpful.

But the data that came from this observational registry will help guide cardiologists who care for athletes with ICDs who want to continue to participate in sports. Shocks may occur, whether appropriately or inappropriately, but knowing this can help open a discussion about the risks of sports participation between the cardiologist and their athletic patient. And it should open up thoughts to how we can better study such patients prospectively to really determine safety of competitive sport participation in those with ICDs.

For more information:

Lampert R. Circulation. 2013;127:2021-2030.