SAN FRANCISCO – Among cases of sports-associated sudden cardiac death in middle-age men, 51% had known preexisting cardiac disease and at least two documented cardiac risk factors, and 31% had cardiovascular symptoms that preceded the sudden cardiac arrest event, results from large ongoing prospective study showed.
"The prevention of SCD during sports should include education of sport participants: The way of practicing sports should be different if you have a known heart disease," and warning symptoms should be heeded, one of the study authors, Dr. Eloi Marijon said in an interview after the annual scientific sessions of the Heart Rhythm Society, where the study was presented.
In the ongoing Oregon-SUDS (Oregon Sudden Unexpected Death Study), Dr. Marijon and his associates identified sudden cardiac arrest (SCA) cases among 944 men aged 35-65 years in the metropolitan area of Portland, Oregon, during 2002-2012, including systematic and comprehensive assessment of their lifetime medical history. "This is the first work aiming to study sudden cardiac death during sports in the community in United States," said Dr. Marijon, a visiting faculty scientist at Cedars-Sinai Medical Center, Los Angeles. "There are some data in the European Union, but data from the United States were coming only from studies carried out among young competitive athletes," he said. These U.S. studies have allowed for significant improvements in the field, notably initiation and optimization of preventive strategies.
However, "recent European experience has emphasized that, in the community, the largest burden of sports-associated SCA results from events among male middle-age participants. However, except for limited data on specific recreational sport activities there are, to the best of our knowledge, no studies evaluating SCA during sports among middle-age subjects in any United States community."
The researchers found that among the 944 SCA cases, 59 (6%) occurred during sports at a mean age of 51 years, which translated into an incidence of 41/million per year. SCA cases associated with sports activity were significantly more likely to be a witnessed event than were those not related to sports (86% vs. 53, respectively), with higher rates of bystander cardiopulmonary resuscitation (46% vs. 26%) and ventricular fibrillation as the presenting rhythm (84% vs. 57%). In addition, survival to hospital discharge was nearly twice as high for sports-related SCA cases than for nonsports–related SCA cases (25% vs. 13%).
The researchers also found that slightly more than half of sports-related SCA cases (51%) had known preexisting cardiac disease and at least two documented cardiac risk factors, while nearly one-third (31%) had cardiovascular symptoms that preceded the SCA event, "opening room for intervention," Dr. Marijon said.
Even though the researchers considered lifetime past medical history in all cases, "investigation of SCA remains particularly challenging, especially since a great majority of subjects die in the field, and consequently the information collected by emergency medical services is often restricted to data regarding the resuscitation process," Dr. Marijon noted. "Details of the past medical history of SCA patients (especially those that cannot be resuscitated) are thus usually sparse and very rarely considered systematically."
The principal investigator of Oregon-SUDS is Dr. Sumeet S. Chugh of the department of genomic cardiology at the Cedars-Sinai Heart Institute.
The study was funded by the National Heart, Lung, and Blood Institute. Dr. Marijon had no relevant financial conflicts of interest to disclose.