Originally Published: 06 MAR 23 12:45 ET

Updated: 06 MAR 23 13:10 ET

By Jacqueline Howard, CNN

(CNN) -- In a new study, most elite athletes with a diagnosed genetic heart disease did not experience serious or fatal symptoms of their condition, such as sudden cardiac death. The research suggests it can be "feasible" and "safe" for athletes to continue to participate in their sport.

Among a sample of 76 elite athletes with a genetic heart disease who had competed or are still competing in either Division I university or professional sports, 73 out of the 76 did not experience a cardiac event triggered by their disease during the study period, according to researchers behind a late-breaking clinical trial presented Monday at the American College of Cardiology's Annual Scientific Session Together With the World Congress of Cardiology.

Among those elite athletes with a genetic heart disease, 40 of them -- 52% -- were asymptomatic, the study abstract finds.

Over the years, researchers have become more aware of alarming reports about elite athletes experiencing heart problems, or even suddenly collapsing during games.

"For athletes with genetic heart conditions, and I would add non-athletes, the tragedies occur when we don't know of their condition," said Dr. Michael Ackerman, a genetic cardiologist at Mayo Clinic in Rochester, Minnesota, who was a senior author of the new research. "When we know of their condition, and we assess the risk carefully and we treat it well, these athletes and non-athletes, they can expect to live and thrive despite their condition."

The new research has not yet been published in a peer-reviewed journal, but the findings suggest that many athletes with a genetic heart disease can decide with their health care professionals on whether to continue competing in their sport and how to do so safely, instead of being automatically disqualified due to their health conditions.

"In sports, historically, we've been paternalistic and de-emphasize patient preference and risk tolerance, but we know that athletes come from all walks of life. They are intelligent and when there's scientific uncertainty, their values should be incorporated in medical decision-making," Dr. J. Sawalla Guseh, cardiologist at Massachusetts General Hospital, who was not involved in the new study, said during Monday's scientific session.

"Shared decision-making when done well can have very favorable outcomes," he said.

Athletes and heart risks

Elite basketball, hockey, soccer and football players, were among the 76 athletes included in the new study, conducted by researchers at Mayo Clinic and other institutions in the United States. They wrote in their study abstract that this is the first study to their knowledge describing the experience of athletes competing at the NCAA Division I level or in professional sports with a known genetic heart disease that puts them at risk of sudden cardiac death.

The athletes in the study were cleared for return-to-play at either a NCAA Division I school or at the professional level. They were studied over an average of seven years, and all had been diagnosed with a genetic heart disease in the past 20 years, being treated at either Mayo Clinic, Morristown Medical Center, Massachusetts General Hospital or Atrium Health Sports Cardiology Center.

"Only three of them had a breakthrough cardiac event, which means after they were diagnosed and treated, they were still having an event," said Katherine Martinez, an undergraduate student at Loyola University in Baltimore, who helped conduct the research as an intern in the Mayo Clinic's Windland Smith Rice Sudden Death Genomics Laboratory.

Fainting was the most common event, and one athlete received a shock with an implantable cardioverter defibrillator, or ICD. None of the athletes died.

"The majority of these athletes went on to continue their career with no events at all," Martinez said. But most of the athletes in the study -- 55 of them, or 72% -- were initially disqualified from competing by their primary provider or institution after their diagnosis. Most ultimately opted to return to play with no restrictions after undergoing comprehensive clinical evaluations and talking with their doctors.

While each sports league has its own set of rules, historically, some people diagnosed with a genetic heart disease that puts them at an increased risk for sudden cardiac death have been restricted from competitive sports, the researchers wrote in their study abstract.

"Just because you were given this diagnosis, doesn't mean that your life, your career, the future that you see for yourself is over, but taking a second opinion from an expert who knows what they're doing and is comfortable with shared decision-making is the next step," said Martinez, who worked on the new research alongside her father, Dr. Matthew Martinez, director of Atlantic Health System Sports Cardiology at Morristown Medical Center and an author of the new research.

Regarding the new study, "the take-home message is, if you have one of these findings, seek out an expert who's going to help you identify a safe exercise plan for you and determine what level you can continue to safely participate in," he said. "This is the next best step -- the next evolution -- of how we manage athletes with genetic heart disease."

'Do we need to take a closer look?'

Leaving their sport due to a genetic heart disease can be "very destructive" for athletes who have devoted their lives to excelling in competitions, said Dr. Lior Jankelson, director of the Inherited Arrhythmia Program at NYU Langone Heart in New York, who was not involved in the new research.

Yet he added that these athletes still need to consult with their doctors and be watched closely because some genetic diseases could be more likely to cause a serious cardiac event than others.

The new study highlights that "the majority of athletes with genetic heart disease could probably -- after careful, meticulous expert risk-stratification and care strategy -- participate in sports," Jankelson said. "But at the same time, this is exactly the reason why these patients should be cared only in high-expertise genetic cardiology clinics, because there are other conditions that are genetic, that could respond very adversely to sports, and have a much higher risk profile of developing an arrhythmia during intense activity."

Separately, the NCAA Sports Science Institute notes on its website, "Though many student-athletes with heart conditions can live active lives and not experience health-related problems, sudden fatality from a heart condition remains the leading medical cause of death in college athletes."

For athletes with a genetic heart disease, their symptoms and their family history of cardiac events should be considered when determining their risks, said Dr. Jayne Morgan, a cardiologist with Piedmont Healthcare in Atlanta, who was not involved in the new research.

"Certainly, there is concern with elite athletes competing and whether or not they are being screened appropriately," Morgan said. But she added that the new research offers "some understanding" to the mental health implications for athletes with a genetic heart disease who may be required to step away from a competitive sport that they love.

"This study, I think, begins to go a long way in identifying that we may not need to pull the trigger so quickly and have athletes step away from something that they love," Morgan said.

The new study is "timely" given the recent national attention on athletes and their risk of sudden cardiac death, Dr. Deepak Bhatt, director of Mount Sinai Heart in New York City, who was not involved in the research, said in an email.

"These are some of the best data showing that the risk of return to play may not be as high as we fear," Bhatt said about the new research.

"Some caveats include that the majority of these athletes were not symptomatic and about a third had an implantable defibrillator," he added. "Any decision to return to the athletic field should be made after a careful discussion of the potential risks, including ones that are hard to quantify. Input from experts in genetic cardiology and sports cardiology can be very helpful in these cases."