COMMENTARY

Lessons Learned From Mandatory Cardiac Screening of Young Athletes

Letter to the Editor

Aneil Malhotra, MB BChir, PhD; Sanjay Sharma, MBBS, MD

Disclosures

November 09, 2018

To the Editor:

Re: Should Mandatory Screening of Young Athletes End?

We read with interest the thoughtful and persuasive commentary by John Mandrola, MD,[1] on our recent study reporting the outcomes of cardiac screening among adolescent soccer players.[2] There are few topics within cardiology that consistently open the proverbial "can of worms" more forcibly than cardiac screening in ostensibly healthy young athletes. This is reflected by the varied range of opinions from Medscape readers and beyond, which transcend medical speciality, occupation, and nationality. Everyone has an opinion, be it an electrophysiologist who has just performed yet another ablation for asymptomatic arrhythmia, or a bereaved parent who has lost a child from sudden cardiac death (SCD).

While the ultimate goal of any pre-participation cardiovascular screening program is to prevent SCD, the first step is to identify those with a condition that predisposes them to SCD. In this regard, the quote from Karl Popper that Mandrola cited is more than appropriate: "The more we learn about the world, and the deeper our learning, the more conscious, specific, and articulate will be our knowledge of what we do not know, our knowledge of our ignorance."[3]

Valuable Lessons

We should therefore start with emphasizing what has been learned from this study. Among the 11,168 adolescent athletes (mean age, 16.4 years) screened with an ECG and echocardiogram, 267 (2.4%) harboured a cardiac condition (1 in 42 athletes). In this group, 42 athletes were diagnosed with conditions associated with exercise-related SCD, all of whom were monitored clinically and the vast majority (71%) of which underwent corrective procedures that enabled them to return to play. Forty of the 42 athletes with serious conditions remained alive at the end of the study period (mean follow-up, 10.6 years). Among the two cases of SCD, both athletes had been diagnosed with hypertrophic cardiomyopathy and continued to participate in competitive sport against medical advice.

The ECG was the most effective screening tool for detecting serious cardiac disease (86%), followed by the echocardiogram (31%), with a meagre 10% detected using the American Heart Association/American College of Cardiology recommendations of a health questionnaire and physical examination.

During the follow-up period of 118,351 person-years, there were 23 deaths, eight (35%) of which were attributable to a cardiac cause. This equates to an incidence of 1 in 14,700 person-years or 6.8/100,000 athletes, which is not particularly high but is at least threefold greater than numbers reported historically.[4] Moreover, in this study the death rate was seven times higher among black athletes than white athletes, replicating a similar difference between black and white national collegiate level basketball players in the United States.[5] Of the eight deaths that occurred, six demonstrated a normal screen at the age of 16 years. The mean period between screening and SCD was 6.8 years.

Costs per QALYs

These were the facts. Now let us examine conjecture. Dr Mandrola states that many individuals undergoing cardiac screening would wrongly be diagnosed with disease. In light of the recent international recommendations for the interpretation of the athlete's ECG,[6] the false-positive rate among adult athletes is just 2%,[7] which is significantly lower than reported false-positive rates (14%) among well-established breast cancer screening programs.

Much is made of the $4 million (£2.9 million) used to screen 11,168 athletes. This cost was calculated over a 20-year period and amounted to $102,782 (£77,000) per serious cardiac disorder identified. We appreciate that most organizations work within financial constraints, and when analysed in terms of quality annual life-years (QALYs), the British government is willing to spend up to $39,000 (£30,000) per QALY. Assuming that athletes with such conditions may gain as many as 60 years of life after intervention, the $1700 (£1300) per QALY seems a paltry sum, particularly when compared with the $31,000 (£25,000) per QALY that a cardiac resynchronization therapy defibrillator device may cost for an elderly patient with end-stage heart failure. Moreover, given the hereditary nature of many cardiac diseases affecting young athletes, identification of a susceptible athlete has the added benefit of detecting other young first-degree relatives through familial assessment.

Six of the eight deaths attributable to a cardiac cause occurred in athletes who demonstrated a normal initial screen at 16 years of age. Although we did not perform serial evaluations to show subsequent development of a cardiomyopathy, the concept of age-related penetrance must be considered because many individuals destined to develop cardiomyopathy do not express the disease during adolescence.[8] Conversely, intense exercise regimens can unmask the phenotype in those at risk. The mean age of presentation in decedents with arrhythmogenic right ventricular cardiomyopathy, for example, is 31 years, and the phenotypic manifestation of the condition is accelerated with exercise.[9] An argument could therefore be made to recommend serial cardiac evaluations during late adolescence and young adulthood. In light of the study findings, the English Football Association has extended the screening program with serial assessments at the age of 18, 20, and 25 years. The University of Washington is following suit.

This study highlights that cardiac screening is not an alternative to providing facilities for early resuscitation and defibrillation. We believe that automated defibrillation provision and implementation should be mandatory.

As Albert Einstein said, "Look deep into nature, and then you will understand everything better." The opportunity to investigate and follow up all members of a specific cohort in this rigorous screening program allowed the generation of an expansive dataset without introducing the inherent risk for selection bias. This mandatory screening program provided invaluable insights into the burden of cardiac disease and the prevalence of SCD in adolescent athletes. In an era in which patient autonomy and shared decision-making are paramount, we are hopeful that findings from our study will aid the consent process for athletes who wish to be screened.

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