Sudden cardiac deaths: one-off screening misses cardiomyopathies in young footballersBMJ 2018; 362 doi: https://doi.org/10.1136/bmj.k3474 (Published 09 August 2018) Cite this as: BMJ 2018;362:k3474
One-off cardiac screening at age 16 failed to detect most cardiomyopathies associated with sudden cardiac deaths in adolescent footballers, a large UK cohort study has found.1 But results from the 20 year study also showed that the rate of sudden cardiac deaths was much higher than expected, prompting the English Football Association (FA) to recommend more frequent cardiac assessments for young footballers.
Sanjay Sharma, study coauthor, said, “The death of a young athlete is highly tragic when one considers that most deaths are due to congenital/inherited diseases of the heart that are detectable during life. Such deaths raise questions about possible preventative strategies.” Sharma is professor of inherited diseases and sports cardiology at St George’s, University of London and chairs the FA’s expert cardiac committee.
The study, funded by the English FA and research charities, screened 11 168 teenage footballers recruited to youth academies at clubs affiliated with the association from 1 January 1996 to 31 December 2016. The mean age of the players at cardiac screening was 16.4 years.
The screening—mandatory for all teenagers joining youth academies who have the potential to become professional footballers—included a health questionnaire, a physical examination, electrocardiography (ECG), and echocardiography.
Researchers collected data on deaths that occurred among the screened cohort using a database compiled from voluntary reports to the FA. They also sent a survey to health professionals working at the football clubs included in the study to ask about deaths from any cause, in addition to obtaining death certificates of any cohort members who died during the study period.
The screening results, reported in the New England Journal of Medicine,1 showed that 42 athletes (0.38%) had cardiac disorders associated with sudden cardiac death, five of whom (0.04%) had hypertrophic cardiomyopathy.
During the follow-up period 23 deaths from any cause occurred. Eight of these (35%) were sudden deaths attributed to cardiac disease, and cardiomyopathy accounted for seven of these deaths (88%).
The overall incidence of sudden cardiac death among the adolescent footballers in the cohort was one in every 14 794 person years, or 6.8 in 100 000 athletes. This figure is at least three times higher than previous estimates of 0.3 to 2.0 in 100 000, depending on the population studied and method used.
Sharma said, “Our results represent the minimum incidence of sudden cardiac death among screened adolescent soccer players. Since we may not have captured all cases of sudden death, the death rate could be higher.”
Five of the seven athletes who died from cardiomyopathy had had a normal ECG and echocardiogram when screened at 16. The mean time between screening and sudden cardiac death was 6.8 years (range 0.1 to 13.2 years).
The authors said, “Screening at this age [16 years] seems logistically appropriate, given that most people will be post-pubertal and will have overt evidence of any electrical or structural cardiac abnormalities.” But they added, “This study shows that screening during late adolescence will fail to detect a substantial proportion of athletes who have or will eventually have a cardiomyopathy.”
They suggested that the disease is not yet manifest at that age or that ECG and echocardiography are not sensitive enough to detect early disease in some adolescents.
“On our advice the FA has now extended the screening process to protect this cohort of young athletes,” said Sharma. The new recommendation is for young footballers to have an ECG at ages 18, 20, and 25, after an ECG and echocardiogram at age 16.
The lead author, Aneil Malhotra, said, “The rationale is to improve the fact that six of the eight players who were screened at the age of 16 years revealed a normal screen and subsequently died. Five of these were due to cardiomyopathies.” Malhotra is NIHR clinical lecturer at St George’s University of London and a member of the FA’s Cardiology Consensus group.
He noted that the sensitivity of ECG is over 90% in detecting cardiomyopathies such as hypertrophic cardiomyopathy. He said, “Either the tests were not sensitive enough, or more plausibly, the players were harbouring subtle or incomplete expressions of cardiomyopathy that manifest later on in adolescence or in their 20s.
“The mean age of presentation from these conditions is in the early 20s, and we know that ECG changes precede echo manifestations of the disease by up to five years. Hence screening with ECG only at 18, 20, and 25 years will go towards addressing this.”
He added, “Longitudinal prospective serial evaluation of footballers will help shed light onto the issue of if and when a cardiomyopathy may manifest. The Football Association recommendations of ECG at 18, 20, and 25 years of age following an ECG and echo at 16 years will provide data to help investigate this.”
In addition, Malhotra suggested that further research is needed to investigate the study finding of a sixfold higher incidence of sudden cardiac arrest among black footballers than white footballers. He said, “Although there were many more white (90%) than black subjects, this corroborates findings in the USA among black basketball players. The reasons behind this ethnic variation should be explored further.”
The BMJ contacted England’s Rugby Football Union to ask whether it had similar screening procedures to the FA. A spokesperson said, “Working with Cardiac Risk in the Young [the charity CRY], we have been screening England representative players at U18, U20 and senior level since 2004, and since 2010 the programme has also included all Premiership players and Regional Academy players about the age of 16.
“We screen every two years from 16 to 20 and have done since 2010. Our processes are currently being reviewed, and CRY and other governing bodies are contributing to the review.