Is cardiac screening the answer?

Recently we saw the unfortunate retirement of English cricket international James Taylor. During a pre-season fixture, he felt ill and was taken to hospital were a scan identified arrhythmogenic right ventricular cardiomyopathy (ARVC).

Such conditions can be exacerbated by exercise and potentially cause sudden death. A similar heart condition led to the on-pitch collapse of professional footballer Fabrice Muamba in 2012. While sudden cardiac death is estimated to be rare, around one in 100,000 people aged 12-35,1 public interest remains high as the emotional events are often highly visible.

The sudden death of an athlete during training or competition is a devastating event and often occurs in asymptomatic individuals with undiagnosed heart conditions, for these reasons it has been proposed that young lives could be saved by screening all athletes.

Around 0.3% of the population suffer from a number of rare genetic and acquired heart disorders that can cause sudden cardiac death.2 Often these young athletes are unaware of their heart condition and the first presentation of the disease is sudden death.

Researchers have focused on screening athletes as exercise has been identified as a potential trigger to sudden death within this population.1 Basic screening consists of taking a patient’s history and doing an examination. However, due to the fact that many patients are asymptomatic and have unremarkable examinations, few patients are identified this way.3 To increase the sensitivity of the screening experts have suggested using an electrocardiogram (ECG).4 It’s estimated that an ECG would increase the sensitivity to 0.75 as it would hopefully pick up arrhythmias, however it would still fail to identify a number of congenital anomalies of the coronary arteries.5 Furthermore, there is a large overlap between a normal ECG and an ECG of someone with a cardiac disease, especially in highly trained athletes.

Mandatory screening of young athletes has been compulsory in Italy since the 1970s and a pivotal paper published in 2006 highlighted that screening had reduced sudden cardiac deaths in athletes by 90%.6 However, without controlled randomised trials it is hard to determine if this was due to a reduction in incidence. Furthermore, this study also highlighted the frailties of the screen as of the 269 athletes that died due to sudden cardiac death 49 had undergone the pre-participation screening.6

Being able to distinguish true positives is only side of the current problem. In a search to increase the sensitivity of the screen, we will almost certainly decrease specificity, leading to false positives. This will ultimately lead to additional cardiovascular testing, which may cause anxiety and psychological harm, unnecessary and unwanted restriction from sports and barriers to insurance and employment.7,8

The Italian screening programme lead to 2% of athletes being disqualified from competition. However, this number is a lot higher than the incidence of cardiac conditions. This suggests that many of these athletes could have gone on to participate in sport without any cardiac complications.9 The issue is further complicated as many of these cardiac conditions don’t have a standard management pathway, so once identified some patients go untreated, while the patients that are treated often have the same risk of death as that of sudden cardiac death.

Even with the relatively low cost of an ECG, screening all young athletes wouldn’t be cost effective due to the low frequency of sudden athletic death. The authors of the Italian study argue that an ECG is a relatively low outlay that can potentially reduce sudden cardiac death by 90%. However, the effectiveness of pre-participation screening has still not been substantiated with solid evidence.

At present, a publicly-funded screening programme for all athletes has the potential to induce more harm than benefit because of the high number of false positive. Lifelong disqualification from sport will have a psychological and financial impact on young athletes. It also leads to young people avoiding exercise and missing out on all the health benefits associated with sport.

However, while I’m not sure a national screening programme is the most appropriate way to tackle sudden cardiac death in young athletes. What I am amazed at is how individuals such as James Taylor and Fabrice Muamba managed to go their whole professional sporting career without their cardiac conditions being picked up. Fabrice Muamba was bought by Blackburn Rovers for 5 million pounds and with an investment of that size you would think that the club’s medical surrounding his transfer would include an ECG.

In the future, if screening becomes more accurate and cost effective, a national programme could save a number of lives. However, until then general strategies such as education may have a role in preventing sudden cardiac death in athletes. Raising awareness among healthcare professionals such as primary care doctors is particularly important. Finally, at a community level, compulsory training in cardiopulmonary resuscitation, especially in coaches and players would save more lives.

References

  1. Semsarian C. Sweeting J. Ackerman MJ. Sudden cardiac death in athletes. BMJ. 2015;350:1218.
  2. Sharma S, Estes A. Vetter L. Corrado D. Clinical decisions. Cardiac screening before participation in sports. N Engl J Med. 2013;369:2049-53.
  3. Magalski A. McCoy M. Zabel M. et al. Cardiovascular screening with electrocardiography and echocardiography in collegiate athletes. Am J Med. 2011;124:511-8.
  4. Corrado D. Pelliccia A. Bjørnstad H. et al. Study Group of Sport Cardiology of the Working Group of Cardiac Rehabilitation and Exercise Physiology and the Working Group of Myocardial and Pericardial Diseases of the European Society of Cardiology Consensus Statement of the Study Group of Sport Cardiology of the Working Group of Cardiac Rehabilitation and Exercise Physiology and the Working Group of Myocardial and Pericardial Diseases of the European Society of Cardiology. Cardiovascular pre-participation screening of young competitive athletes for prevention of sudden death: proposal for a common European protocol. Eur Heart J. 2005;26:516-24.
  5. Maron J. Doerer J. Haas S. Tierney M, Mueller O. Sudden deaths in young competitive athletes: analysis of 1866 deaths in the United States, 1980-2006. Circulation. 2009;119:1085-92.
  6. Corrado D, Basso C, Pavei A, Michieli P, Schiavon M, Thiene G. Trends in sudden cardiovascular death in young competitive athletes after implementation of a preparticipation screening program. JAMA. 2006;296:1593-601.
  7. Maron J. Friedman A. Kligfield P. et al. American Heart Association council on clinical cardiology, advocacy coordinating committee, council on cardiovascular disease in the young, council on cardiovascular surgery and anesthesia, council on epidemiology and prevention, council on functional genomics and translational biology, council on quality of care and outcomes research, and American College of Cardiology. Assessment of the 12-lead ECG as a screening test for detection of cardiovascular disease in healthy general populations of young people (12-25 Years of Age): a scientific statement from the American Heart Association and the American College of Cardiology. Circulation. 2014;130:1303-34.
  8. Carroll E. How useful are screening tests? JAMA. 2015;313:1304.
  9. Nishimura A. Ommen R. Tajik J. Cardiology patient page. Hypertrophic cardiomyopathy: a patient perspective. Circulation. 2003;108:e133-5.

 

 

 

 

 

 

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s