April 03, 2014

WASHINGTON, DC — In the end, it really wasn't much of a debate at all. Two experts, citing similar research, made the case that most athletes with heart problems requiring an implantable cardioverter defibrillator (ICD) should be allowed to participate in sports.

While there did appear to be some argument as to exactly what those sports might be—for example, there is a big difference between football, hockey, and rugby compared with low-impact sports like cycling and soccer—the two researchers agreed that most of these athletes can engage in sports without harm.

The debate, which included Dr David Cannom (University of California, Los Angeles) and Dr Rachel Lampert (Yale University School of Medicine, New Haven, CT), took place recently at the American College of Cardiology 2014 Scientific Sessions .

"The most important factor to consider is the underlying diagnosis," Cannom told heartwire . "If there are other reasons, the diagnosis is far and away the most important. I think it's also important to make sure the athlete wants to participate. Sometimes they're getting pushed into it by their parents and they're looking for a way out. It's important to get the mother, the father, the kid, and me in a room and make the decision together."

For Cannom, catecholaminergic polymorphic ventricular tachycardia (CPVT), an arrhythmia that is most prevalent when an individual is under physical or emotional stress, and arrhythmogenic right ventricular dysplasia (ARVD), are two conditions that should preclude participation in sports. For individuals with coronary disease, he is less concerned as long as the patient is checked out periodically with treadmill testing.

During the debate, Lambert agreed, noting that it remains critical for physicians to distinguish between CPVT and idiopathic VT/ventricular fibrillation. Lampert quoted Dr Michael Ackerman (Mayo Clinic, Rochester, MN), saying that it's not that CPVT patients can't participate in sports, but rather that inadequately treated CPVT patients can't participate. For CPVT patients wishing to engage in physical activity, she recommends consulting an expert who regularly manages these individuals so they're treated appropriately.

Death of Hank Gathers Changed the Game

Speaking during the debate, Cannom said the safety of sports for athletes with ICDs is a relative new issue, one that is in the process of redefinition. During his talk, Cannom cited the case of Eric "Hank" Gathers, a 23-year Loyola Marymount University basketball player who collapsed and died on the court during a game in 1990. Gathers had a first syncopal episode a few months prior, and while an ICD was recommended for what was diagnosed as exercise-induced VT, he refused it because he wanted to play professional basketball in the National Basketball Association (NBA).

"This was tragic for the Gathers family, but it was also tragic for a generation of athletes that came just after him," said Cannom. "His death sent chills down the spine of every athletic director and every lawyer who was trying to certify athletes with cardiac problems."

Cannom also discussed the recent case of a 20-year-old Pepperdine University basketball player who had a syncopal episode. Diagnosed with hypertrophic cardiomyopathy, the physicians implanted an ICD. However, after waiving liability and receiving a supporting letter from Cannom, the player was told he could not play because the Bethesda Guidelines—the 2005 document on eligibility recommendations for competitive athletes with cardiovascular abnormalities—recommend restricting athletes with an ICD for primary or secondary prevention from participating in sports. The player eventually transferred to Texas Tech University where he was allowed to play, but even this required a signed waiver from a leading cardiologist in the state.

The Bethesda Guidelines, said Cannom, are based largely on clinical experience and expert opinion rather than on clinical trials. In fact, the data are scant supporting the recommendations in the document.

Given the limitations of the existing guidelines, Cannom and Lampert established a prospective registry to evaluate the safety of sports for athletes with ICDs. They identified 372 athletes participating in organized or high-risk sports (mean age 33 years). Long-QT syndrome was the most common cardiac diagnosis (20%), while hypertrophic cardiomyopathy was also common (17%).

Published just last year, the registry showed that over 31 months of follow-up, no patients died or had a cardiac arrest requiring resuscitation during sports. In addition, there were no arrhythmia- or shock-related injuries during the activity. In total, 37 athletes received 49 shocks during a practice or a game. There were 39 shocks in 29 participants during other physical activity and 33 shocks in 24 athletes at rest. There were eight ventricular arrhythmias picked up by the ICD, and these were all terminated by the device. After receiving a shock, four stopped participating in sports entirely, but the majority remained engaged in activity.

"This is a large sample size, and we found that most athletes who participate in sports can do so without harm or injury," said Cannom. "The ICD shocks occurred, but there were no tachyarrhythmia deaths. The notion that we developed is that sports are giving these patients back a quality of life they had lost when they received a diagnosis of, say, long-QT syndrome or hypertrophic cardiomyopathy. While shocks can decrease quality of life, so too can sports restriction."

Cannom told heartwire the registry includes some really "unusual" people, noting that more than half of those with an ICD had a previous cardiac arrest that led to the implant, yet they returned to sports. Lampert said the registry did not measure quality of life, but the participants "voted with their feet." Even the shocks did not hold them back, with two-thirds returning to their sport. Two runners had appropriate shocks while running a marathon, yet they finished the race. "That's the kind of crazy people in this study," she said.

Lead Survival and Different Sports

During the debate, Lampert tackled the issue of whether these data support participation in any or all sports. There were a large number of athletes participating in running, including marathons, as well as basketball, baseball, and soccer players. There were not a lot of high-intensity, contact sports, the type of sports where the "whole reason to buy a ticket is to watch these people bash each other into the ground and get carried off the field."

Lead survival in the registry—97% and 90% freedom from lead malfunction at five and 10 years, respectively—was in line with other data. It is unknown whether this would be the case with athletes participating in football, rugby, or hockey. In addition, every patient in the registry had a transvenous ICD, and while the registry is ongoing, there are no data yet as to how well leads for a subcutaneous ICD, which are not protected by the thorax, would hold up with more physical sports.

To heartwire , Cannom said that he is aware of at least one patient playing in the NBA with a subcutaneous ICD. He wears a Kevlar vest that wraps around his ribcage to protect the device from physical contact. Hockey players, however, might have more problems with the subcutaneous device than basketball players, given the level of contact during a game, he said.


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