Objective The IOC recommends periodic cardiovascular screening of athletes, but the adoption of these recommendations is unknown. The purpose of this investigation was to evaluate and compare cardiovascular screening practices of countries participating in the Rio 2016 Olympic Games.
Methods A list of chief medical officers (CMOs) was compiled by the IOC during the 2016 Olympic Games. CMOs were requested to complete an online survey about cardiovascular screening of their countries’ Olympic athletes. Comparisons of screening practices were made by categorising countries by continent, gross domestic product (GDP) per capita and size of athlete delegation.
Results CMOs for 117/207 (56.5%) countries participating in the 2016 Olympic Games were identified. 94/117 countries (80.3%) completed the survey, representing 45.4% of all countries and 8805/11 358 (77.5%) of all 2016 Olympic athletes. Most of the countries surveyed (70.2%) perform annual cardiovascular screening. Among the survey respondents, all or most athletes from each country were screened at least once with the following components: personal history (86.2% of countries), family history (85.1%), physical examination (87.2%), resting ECG (74.5%), echocardiogram (31.9%) and stress test (30.8%). Athletes were more likely to be screened with ECG in countries with relatively larger athlete delegation (OR 2.05, 95% CI 1.10 to 3.80, p=0.023) and with higher GDP per capita (OR 1.69, 95% CI 1.11 to 2.57, p=0.014).
Conclusion Most of the responding countries perform annual cardiovascular screening of Olympic athletes, but there are differences in the components used. Athletes from countries with larger athlete delegations and higher GDP per capita were more likely to be screened with ECG.
- athlete’s heart
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Exercise and sport participation can trigger sudden cardiac arrest (SCA) in athletes with underlying cardiovascular abnormalities.1–3 These conditions are often asymptomatic prior to the onset of SCA.4–6 There is universal agreement regarding the importance of emergency planning to prevent sudden cardiac death (SCD) in sport by means of early recognition of SCA and defibrillation with automated external defibrillators.7–10 Alternatively, primary prevention with cardiovascular screening may identify at-risk athletes with occult cardiac pathology.11
A stated goal of the periodic health evaluation (PHE) is to detect conditions that place athletes at the risk of injury or illness and specifically sudden death in sport.12 Screening for cardiac abnormalities is therefore routinely performed by medical providers caring for athletes of all levels. In the USA, cardiovascular screening of athletes involves reviewing personal and family history and performing a physical examination every 1–2 years. This is the approach advocated by the American Heart Association and adopted by most high school and many collegiate athletic teams in the USA.13
Over the past decade, the traditional screening strategy with history and physical examination has been questioned as a result of an Italian study that demonstrated a reduction in SCD through a mandatory screening programme that included a resting ECG and subsequent studies that showed a low sensitivity of history and physical examination to detect cardiovascular conditions.14–16 Simultaneously, athlete-specific ECG interpretation criteria have been developed, optimising the ability to differentiate pathology from the benign training-related cardiovascular changes described as ‘athlete’s heart’, thus decreasing the false-positive rates. These include the European Society of Cardiology (ESC) Criteria in 2010, Stanford Criteria in 2011, Seattle Criteria in 2013, Refined Criteria in 2014 and most recently International Consensus Standards in 2017.17–20
As a result, cardiovascular screening inclusive of ECG has been recommended by the ESC for many years21 and is now required by most of the international sport governing bodies, including the FIFA, Fédération Internationale des Sociétés d’Aviron and Union Cycliste Internationale, as well as all major professional sports leagues in the USA: NFL, Major League Baseball, NBA, Women’s NBA, NHL, and Major League Soccer. Several professional leagues recently began screening athletes with stress echocardiography as well.22
In 2009, the IOC published a consensus statement on PHE of elite athletes recommending screening athletes with a personal and family history questionnaire, physical examination and resting 12-lead ECG.23 In our preceding study, the US National Governing Bodies (NGBs) and National Paralympic Committees were found to have varying approaches to cardiovascular screening of athletes.24 The purpose of the current study is to evaluate the cardiovascular screening practices of countries participating in the Rio 2016 Olympic Games and the relationship of ECG screening with gross domestic product (GDP) per capita and size of athlete delegation. The hypothesis was that cardiovascular screening strategies vary among countries participating in the Rio 2016 Olympic Games.
Chief medical officers (CMOs) for National Olympic Committees (NOCs) of the Rio 2016 Olympic Games were surveyed regarding the cardiovascular screening practices of their respective teams. Names and contact information of the CMOs were provided by the IOC. The assessment included questions regarding the CMO’s medical specialty, duration of involvement with their country’s NOC and existing mandates regarding cardiovascular screening. For each cardiovascular screening component, the CMO was asked to indicate the proportion of athletes who undergo screening and the frequency of screening. Questions regarding criteria for ECG interpretation or why an ECG was not used during screening were also asked. Economic data for countries were obtained from the International Monetary Fund April 2015 World Economic Outlook database.25
The primary outcome was the utilisation of cardiovascular screening components as part of the country’s PHE. The secondary outcomes were the frequency of performing the various cardiovascular screening components. A multivariable logistic regression model was used to evaluate the relationship between each country’s GDP per capita and number of athletes on ECG screening practices. The binary outcome was categorised as ECG screening in all or most athletes (yes/no). Quartiles for GDP per capita and number of athletes were created based on the data distribution. For GDP per capita, the categories were <US$2985, US$2986–US$10545, US$10 546–US$31860 and >US$31 860. For number of athletes, the categories were <12, 13–50, 51–121 and >121. These two variables were used as ordinal variables in the model, and the SEs were adjusted for any clustering effect within the same continent. A variable was statistically significant if the 95% CI did not cross the null value of 1.
CMOs for 117 of 207 NOCs (56.5%) were identified with assistance from the IOC. Of the 117 identified CMOs, 94 (80.3%) completed a survey regarding cardiovascular screening of their Olympic athletes. These 94 responding countries represented 45.4% of all countries and 8805 of 11 358 total athletes (77.5%) of all athletes participating in the Rio 2016 Olympic Games. The median years of involvement of the CMO with their respective NOC was 12 years. Primary care (family medicine, internal medicine and paediatrics) was the most common primary medical specialty of the responding CMOs with 42.6%, followed by orthopaedic surgery (19.1%), sports and exercise medicine (13.8%), physiatry (9.6%) and emergency medicine (3.2%). Other specialties comprised the remaining 11.7%. PHEs were performed by NOC or NGB medical providers in 72.6% of responding countries. CMOs reported that written mandates regarding the PHE existed for 54 of 94 countries (57.4%), of which 70.4% specified the frequency of the PHE and 79.6% specified the cardiovascular screening components.
Cardiovascular screening components
The following screening components were reported as being performed at least once in all or most athletes: 81 of 94 countries (86.2%) screened with personal history, 80 (85.1%) with family history, 82 (87.2%) with physical examination, 70 (74.5%) with ECG, 30 (31.9%) with echocardiogram and 29 (31.9%) with stress test (table 1). When measured in combination, the majority of countries screened all or most athletes at least once with at least personal history, family history and physical examination (75 countries, 79.8%). Of those 75 countries, 62 screened with ECG as well as personal history, family history and physical examination (66.0% of all countries). Fifteen countries (16.0%) reported screening some or few athletes with ECG. The remaining nine countries (9.6%) did not screen any athlete with ECG. Figure 1 illustrates the geographic variations in cardiovascular screening using ECG.
Cardiovascular screening frequency
Most countries performed annual cardiovascular screening (table 2) with 66 of 94 countries (70.2%) screening all or most athletes with at least one component annually. Specifically, personal history and family history were performed annually in 47 (58.0%) and 40 (50.0%) of the countries that screen all or most athletes, respectively. For the countries who use ECG for all or most athletes, it is performed with the initial evaluation in four countries (4.9%), more than initial evaluation but less than annually in 15 (21.4%) and annually in 49 (70.0%).
Reasons for not using ECG were reported by nine countries. The most commonly cited reasons were the following: expense of follow-up tests (5 of 9; 55.6%), expense of performing ECG screening (4 of 9; 44.4%), lack of cardiology consultant (4 of 9; 44.4%) and lack of ECG equipment (3 of 9; 33.3%). Most of the countries that screen athletes with ECG reference the ESC (30.1%), Seattle Criteria (9.6%), Refined Criteria (6.9%) or Stanford Criteria (4.1%). An additional 21.9% of CMOs reported using more than one criteria, 4.1% used an unlisted criteria and 23.3% did not know which criteria were used.
Multivariable analysis of ECG screening
A total of 92 countries (98%) responded to the questionnaire with information to classify the outcome of ECG screening in all or most athletes for the multivariable model. The ORs and 95% CIs are shown in table 3. Both GDP per capita and number of athletes were statistically significant, with each category increase for both variables independently contributing to greater use of ECG screening in participating countries.
The IOC recommends periodic cardiovascular screening of athletes, but until now, the adoption of these recommendations among countries participating in the Olympic Games has been unknown. Cardiovascular screening practices may vary with some countries adopting the traditional medical history and physical examination, while others may include an ECG or even advanced imaging and other screening modalities. The decision as to which screening protocol is chosen may depend on several factors such as screening mandates, local practices, belief in cost-effectiveness, available resources and infrastructure for cardiovascular evaluation.
Data from this investigation were compiled using survey information from countries that represented 77.5% of all athletes who competed in the Rio 2016 Olympic Games. The majority of countries had written mandates regarding the PHE, including the frequency and components of cardiovascular screening. Interestingly, nearly 75% of countries included an ECG in the screening of all or most of their athletes, which is notable given the controversy and debate surrounding the inclusion of an ECG during the PHE as well as the fact that the IOC recommends but does not mandate ECG screening.
Results from this investigation provide three major findings: (1) The majority of Olympic athletes receive an ECG as part of their PHE; (2) Developed countries and those countries with a larger number of athletes were more likely to use an ECG; (3) Cost and lack of infrastructure are the major obstacles for countries who do not use an ECG during screening. Of note, countries that used an ECG still had room for continued quality improvement. For example, many countries used older athlete-specific criteria for ECG interpretation and nearly a quarter (23.3%) of CMOs were unsure of the criteria used to interpret their athletes’ ECGs. Improved utilisation of the latest criteria may be achieved by specifying the recommended criteria in future revisions of the IOC consensus statement.
This two-tiered approach to cardiovascular screening for Olympic athletes highlights socioeconomic differences and inequality that exists among countries, such that wealthier countries have higher standards for screening. While a level playing field may not be possible in the athletic realm, screening for rare diseases that predispose athletes to potentially lethal conditions can be a matter of life or death and evaluation practices should be as uniform as possible. To address this disparity, a strategic plan could be developed to close the gap in screening standards. This may include using the physician expertise in sports cardiology that may be seen in more developed countries, developing affordable educational courses to assist in programme development, and constructing/promoting freely available online modules (such as those from BMJ Learning on ECG screening) that can assist all team physicians with the advancement of their screening evaluation.
In addition to the limitations in resources and infrastructure reported by some countries that affect cardiovascular screening, the variations in screening strategies seen in this study could reflect an individualised assessment of the risk of SCA and cost-effectiveness of screening. The American Medical Society for Sports Medicine published a position statement on cardiovascular screening in 2016 that recognised the knowledge gaps and advocated for a careful assessment of the risk of SCA in their specific athlete population and also determine the available resources and infrastructure for cardiovascular evaluation.26 The incidence of SCA in Olympic-level athletes remains unknown. However, the prevalence of cardiovascular abnormalities was found to be 4% in athletes screened by the Italian NOC when using history, physical examination, resting and exercise ECG, and echocardiogram.27
Strengths and limitations
This is the first study to assess cardiovascular screening practices among the countries who provide care for their Olympic athletes. The study is limited by the inability to identify CMOs for 90 of 207 countries and receive responses from 23 of the identified CMOs. However, this only represented 22.5% of all athletes who participated in the Rio 2016 Olympic Games. It is likely that these countries without identified CMOs and with smaller athlete delegations have less resources and infrastructure for cardiovascular screening, which may further magnify the socioeconomic disparities for screening found in this investigation. Lastly, the prevalence of cardiovascular disease and the results of cardiovascular screening within the different countries were not assessed in this investigation, which could be an area for future research.
Among responding countries that participated in the Rio 2016 Olympic Games, cardiovascular screening was regularly performed with variation in the components and frequency. Wealthier countries (as measured by GDP per capita) and those with larger athlete delegations were more to screen athletes with an ECG. The results of the study will support the IOC in its efforts to encourage NOCs to achieve the recommended PHE standards and also be a resource for NOCs when evaluating their own cardiovascular screening strategy.
What are the findings?
Most responding countries perform annual cardiovascular screening of Olympic athletes, but there are differences in the screening components used.
Nearly three-quarters of responding countries screen all or most athletes with ECG.
For countries that do not screen athletes with ECG, the most common reasons were expense of follow-up testing, expense of ECG tests and lack of cardiology consultants.
How might it impact on clinical practice in the future?
Medical team members at every level of sports should assess the risk of sudden cardiac arrest (SCA) in the athletes under their care.
Cardiovascular screening strategies should reflect the SCA risk of the athletes and available resources and infrastructure.
Once a screening strategy has been defined, it must be consistently performed and refined based on the latest research.
The authors wish to acknowledge Professor Lars Engebretsen and the IOC Medical and Scientific Commission for making this study possible.
Contributors BGT: concept, design, acquisition of data, analysis of data, interpretation of data, drafting the manuscript, approval of final version. IMA: concept, design, interpretation of data, drafting the manuscript, critical revising, approval of final version. SAR: design, interpretation of data, critical revising, approval of final version. DIL: analysis of data, interpretation of data, critical revising, approval of final version. CJC: concept, design, critical revising, approval of final version.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent Not required.
Ethics approval The study was approved by Hospital Special Surgery Institutional Review Board on 5 May 2016 and renewed on 5 October 2017 (study ID 2015-691).
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement No additional data are available.
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