How Seriously Should We Take the Risk for SCD?
When midfielder Marc-Vivien Foé collapsed in the center circle of a French soccer field in 2003, sports medicine changed forever.
Foé's death during an international match showed just how poorly the world of professional sports had attended to sudden cardiac death (SCD), the leading medical cause of death among athletes. According to press reports, several minutes passed before anyone attempted to defibrillate the 28-year-old Cameroonian. An autopsy later revealed hypertrophic cardiomyopathy.
Not only could his condition have been diagnosed long before he collapsed, but immediate defibrillation also might have revived him. Now professional sports leagues have begun to institute screening and make automated external defibrillators (AEDs) available. I'd like to see both of these programs expanded throughout competitive sports.
By the 2006 World Cup, the Fédération Internationale de Football Association (FIFA) had instituted screening for professional soccer players and referees with echocardiography and electrocardiogram (ECG) as part of a comprehensive medical examination. And in 2013, the organization began distributing medical emergency bags with AEDs to all 209 member associations.
Sports medicine has been divided on the screening part of this two-pronged approach. The Sports Cardiology Study Group of the European Society of Cardiology recommends universal ECG screening prior to sports participation. But the American Heart Association (AHA) recommends only a cardiovascular-oriented history and physical examination. Opponents of mandatory ECG screening argue that it is not cost-effective and that false positives would unnecessarily bar too many athletes from sports.
Inaccurate Estimates of the Incidence of SCD
In part, these arguments rest on inaccurate estimates of the incidence of SCD. For example, the US Registry of Sudden Death in Athletes (USRSDA) attempted to extrapolate the number of sudden cardiac deaths by using media reports, reports by next of kin, and electronic databases. The researchers arrived at an incidence of 1 death in 164,000 US athletes.
But studies in US college athletes, using more precise numbers of athletes and deaths, suggest that the incidence is closer to 1:50,000.
That puts US numbers more in line with a prospective cohort study in the Veneto region of Italy, in which the reported rate was 1:28,000 from 1979 to 1980 per athlete. The incidence sank to 1:250,000 in the Veneto cohort from 2003 to 2004 following the implementation of mandatory screening with ECG throughout Italy.
There was no change in the incidence of SCD in the general population during this time, suggesting that the screening program prevented athletes' deaths by disqualifying those most at risk from sports.
Of course, initial screening will produce some false positives. But by using ECG and echocardiogram together with a detailed history and physical exam, we can flag those athletes who need further testing. Once these more extensive tests are completed, the risk for an unnecessary disqualification is low.
And it's worth noting that the AHA program of physical exams and family history without ECG can also produce false positives. In a study of 1596 US professional, college, and high school athletes, 23.8% had at least one positive response to the AHA personal and family elements questions.
As technology improves, screening will become increasingly accurate. And screening itself will improve our understanding about the way risk factors vary.
Already we have learned about important demographic differences in athletes. Male athletes appear much more likely than female athletes to suffer from SCD. The most common cause of SCD in athletes in the United States appears to be hypertrophic cardiomyopathy, while in Italians it appears to be arrhythmogenic right ventricular cardiomyopathy.
Age matters too; in the United States, arteriosclerosis is the most common cause of SCD among athletes over age 40.
FIFA has set up a registry to analyze SCD during soccer matches. As we learn more about this condition, our ability to screen for it will also improve.
Medscape Orthopedics © 2015 WebMD, LLC
Any views expressed above are the author's own and do not necessarily reflect the views of WebMD or Medscape.
Cite this: Is SCD in Athletes Too Rare to Warrant Serious Precautions? - Medscape - Jun 19, 2015.