Assessment of cardiovascular risk among school athletes: A retrospective cross-sectional study

Sri Lankan situation

At present, Sri Lanka lacks a comprehensive database for cardiovascular abnormalities or sudden deaths among young athletes. However, numerous deaths have been reported in this population, particularly during endurance sports. Public concern about this health issue grew significantly following four consecutive deaths during school marathon races in January 2013. Between 2013 and 2024, a total of 14 sudden deaths were recorded during endurance events. Sadly, nearly all of these individuals had not undergone any cardiovascular risk assessments.^[10]

Structural cardiac abnormalities such as ASD, VSD, and rheumatic valvular conditions like MVP are occasionally identified when athletes visit sports medicine clinics for pre-participation medical clearance. Although no official statistics have been published, heat stroke is believed to be a leading trigger of fatal cardiac arrhythmias, contributing to unexpected fatalities among young endurance athletes in Sri Lanka. Other cardiac causes, including myocarditis, hypertrophic cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy, are also significant contributors. In addition, commotio cordis, a sudden non-penetrative impact to the chest, can induce fatal arrhythmias, resulting in the death of a young athlete. The occurrences of sudden deaths among young athletes during sporting events since 2013 have prompted governing bodies to focus on implementing proper PPE assessments for all athletes before engaging in endurance sports. To battle against such sudden athletic deaths, on 8^th of April 2015, the Ministry of Health launched a comprehensive PPE and pre-event program to screen all due athletes. Through the Ministry of Health, the government has issued a circular declaring the mandatory PPE screening, the (H-1246) clearance certificate by the government circular.^[10-14]

Justification

Adolescents participating in endurance sports with undetected cardiovascular risks face potentially life-threatening situations. Many of these deaths could be prevented through comprehensive pre-participation assessments and medical clearance implemented nationwide. To address this, the Ministry of Health in Sri Lanka introduced an assessment tool (H-1246) in 2015 to reduce sudden athletic deaths in selected endurance and contact-collision sports.^[11-13] However, data on cardiovascular risk factors in Sri Lankan athletes remain unpublished and poorly understood.

To address this gap, a pilot study will be conducted at a Sports Medicine clinic in the Teaching Hospital, Galle. This study aims to identify cardiovascular risks in adolescent school athletes participating in endurance sports. The findings will serve as a foundation for further research in sports medicine, contributing to the enhancement of existing preventive strategies or the development of new measures to mitigate these risks.

Objectives

Study design

This is a retrospective cohort study.

Setting

The study was carried out at the Sports Medicine Unit of National Hospital Karapitiya, Galle, Sri Lanka, from January 1, 2022 to June 30, 2023.

Data collection method

The research utilized archived clinic records of athletes who visited the Sports Medicine Unit at Teaching Hospital Karapitiya. Risk assessment involves reviewing medical history, conducting physical examinations, and performing basic medical investigations when necessary.^[10,15]

Trained sports medicine physicians identified adolescent school endurance athletes with cardiovascular risks that could impact their participation in endurance sports during the medical clearance process. In accordance with the protocol and guidelines set by the Sports Medicine Development Committee of the Ministry of Health in Sri Lanka, only authorized medical officers or consultants in sports medicine are allowed to issue the PPE clearance certificate (H-1246). Therefore, the questionnaires kept in the clinic were filled out by these authorized professionals, who affixed their signatures and official stamps onto the documents.

Data collecting instrument

Further, all athletes seeking the H-1246 PPE clearance certificate must submit the standardized application form along with an ECG in advance. The application form is designed as a comprehensive medical history questionnaire and also allows space for a medical officer to document the clinical examination findings, investigation results, referrals made to any other medical specialties, endurance test results, diagnosis, and final inferences of the athlete’s cardiovascular fitness level. Those completed questionnaires should be signed and stamped by the medical officer and also be kept for a minimum of 1 year. The relevant data for the research were extracted from those questionnaire forms, which were archived in the clinic record room and then transferred to the data extraction sheets as secondary data [Supplementary material]. The study utilized the collected data to identify the prevalence of cardiovascular risks and the factors linked to these risks among adolescent school athletes involved in endurance sports.

Participants

A representative group of 784 athletes who visited the clinic requesting pre-participation medical clearance, the (H-1246) clearance certificate between the 1^st of January 2022 and June 30^th of 2023, over a period of 18 months, were selected.

Inclusion criteria

Adolescent school endurance athletes aged between 10 and 19 years.

Taking part in a sport with a mandatory PPE screening, the (H-1246) clearance certificate by the government circulars by the Ministries of Health and Education includes running 1500 m and or above running, swimming 400 m and or above, martial arts, boxing, cadeting, rugby, soccer, race walking, cycling, hiking, and any other sport when an athlete is having a significant health issue.^[10]

Exclusion criteria

Non-schooling adolescent athletes.

School adolescent endurance athletes requesting the (H-1246) clearance certificate for any sport other than the mandatory government-designated sporting events mentioned above. The rationale for focusing on school athletes stems from the study’s objective to produce data that are directly relevant to the school setting. This approach facilitates the development and implementation of targeted injury prevention programs within schools. Moreover, the structured and organized nature of school sports programs ensures greater consistency and control in data collection while providing easier access to participants through the school system. In contrast, non-school adolescent athletes often engage in more varied and less structured sports environments.

Variables

Analysis was done on age, gender, sport, ECG analysis, and cardiovascular examination findings.

Data sources/management

Experienced sports medicine physicians and a pediatric cardiologist meticulously handled the data obtained from the clinic records.

Bias

The risk was minimal as sports physicians extracted data retrospectively from standard sources and filled gaps by contacting athletes when necessary.

Study size

Simple random sampling was used.

The sample size was calculated based on an anticipated prevalence of abnormalities at 15%, referencing a study in the USA by Price et al., 2014.^[9]

The sample size was calculated using the following formula: Lowanga and Lameshow, 1991, and considering the anticipated prevalence as 15%.^[16]

(*z=1.96, **P=0.15, ***d=0.025)

n = 783.7

Data from 784 students were analyzed.

n = Number of participants (sample size), *z = Level of confidence (level of significance - 0.05), **d = absolute precision, ***P = estimated proportion of individuals in the sample with the characteristics of interest.

Statistical method

The data analysis was conducted using the Statistical Package for the Social Sciences software, version 25. Descriptive statistics were applied to present the basic sociodemographic information, while cross-tabulation was utilized to compare various groups of athletes. As all data were directly obtained from fully completed, archived questionnaires, the study did not encounter any confounding variables, missing data, or loss to follow-up. In cases requiring additional clarification, patients could be contacted using the mobile number or school postal address provided on the questionnaires.

Participants

About 1117 eligible questionnaires have been archived in the clinic record room for the period of analysis. About 784 questionnaires were randomly selected and retroactively analyzed.

Descriptive data

Based on the study sample, as presented in Table 1, male marathon participants accounted for 63.3% (497), while females made up 36.7% (287). This highlights a greater inclination among male adolescent athletes to participate in marathons compared to their female counterparts. The higher incidence of fatal events among male athletes has been attributed to their greater participation in competitive sports, coupled with more rigorous training regimens and higher levels of athletic performance compared to females.

As indicated by the study sample in Table 2, marathon participation was comparatively higher among athletes aged 16-19 years. This trend could be attributed to athletes in this age group having more established training routines, greater experience, and increased confidence in competing in endurance events.

Outcome data

Based on the analysis of Table 3, the prevalence of cardiovascular abnormalities was determined to be 3% (24 cases). The most frequently identified condition was mitral valve prolapse, accounting for 1.4% (11 cases). Other detected abnormalities included mitral stenosis (MS) at 0.2% (2 cases), VSD at 1.2% (9 cases), and AS at 0.2% (2 cases).

A notable finding during pre-participation examinations is the presence of cardiac murmurs. As shown in Table 4, the prevalence of heart murmurs within the sample is 2.8% (22 cases).

Analyzing the ECG [Table 5] is crucial in PPE examinations. The prevalence of detected electrocardiographic abnormalities was 5.6% (44 cases). The addition of a 12-lead ECG notably improves the sensitivity of the screening process in identifying cardiac conditions that increase the risk of sudden deaths while engaged in physical activities. Maron, 2005, stated that up to 95% of individuals with hypertrophic obstructive cardiomyopathy (HOCM) - the leading cause of instant cardiac demise among adolescent athletes - exhibit abnormal electrocardiographic findings.^[17] Similarly, according to Corrado et al., 1988, ECG abnormalities have been frequently reported in many athletes who succumbed to arrhythmogenic right ventricular dysplasia.^[18]

From the analysis of Table 6, it can be inferred that the most frequently observed ECG abnormality was the right bundle branch block (RBBB), accounting for 2.8% (22 cases). RBBB is generally considered a benign finding in young athletes, often reflecting physiological cardiac remodeling due to regular, intense physical activity. Other abnormalities included T-wave inversion in individuals over 16 years of age at 1.7% (14 cases). T-wave inversion in this age group has clinical significance since it may warrant further evaluation to rule out underlying structural or functional cardiac abnormalities, particularly when found in specific leads or associated with clinical symptoms. Further, ectopic beats at 0.5% (4 cases) and right ventricular hypertrophy (RVH) also at 0.5% (4 cases) were detected. While ectopic beats are relatively common and often benign in athletes, RVH requires careful assessment to differentiate physiological adaptations from pathological conditions such as pulmonary hypertension or congenital heart disease.

Running events exceeding 1500 m were found to have the highest prevalence of cardiovascular and/or ECG abnormalities, accounting for 42% (28 cases) [Table 7]. Other sports with notable prevalence included swimming events over 400 m at 18% (12 cases), martial arts at 15% (10 cases), and cycling/hiking at 7.5% (5 cases), from a total of 66 detected cardiovascular and/or ECG abnormalities.

Table 8 illustrates the cross-tabulation analysis of age versus the detection of abnormal ECG findings with the measures of association. The prevalence of abnormal ECGs was approximately 3% in the 10-12-year age group, while the ≥13-year age group had a prevalence of 2.55%. Similarly, the 10-15-year age group demonstrated a prevalence of 4.20%, whereas the ≥16-year age group showed a lower prevalence of 1.40% for abnormal ECGs.

Key results

Participation in sports among school athletes has notably decreased in recent years, largely due to the unforeseen sudden cardiac deaths of adolescent school athletes. These catastrophic events have had a significant effect on sports participation, leading many parents to hesitate in permitting their children to take part in endurance competitions. Without a proper PPS system, young athletes engaging in endurance sports face a heightened risk of career-ending outcomes. A scientific evaluation of cardiovascular risk factors through comprehensive pre-participation clinical assessments is therefore essential to prevent sudden cardiac deaths during events such as marathons.

This research, conducted at the Sports Medicine Clinic of the Teaching Hospital Karapitiya in Sri Lanka, identified a 3% prevalence of cardiovascular abnormalities among school athletes. A total of 68 cardiovascular irregularities were documented, including 24 cases of valvular heart disease and 44 ECG abnormalities across various sports. In addition, 11 physiological murmurs were observed. Out of the 24 valvular defects, 22 were detected through meticulous auscultation of murmurs, while the remaining two were confirmed using echocardiography.

The most common abnormality was mitral valve prolapse (1.4%, 11 cases). Other detected conditions included MS (0.2%, 2 cases), VSD (1.2%, 9 cases), and AS (0.2%, 2 cases). There were 118 (15.1%) individuals in the age category of 10-12 years, 164 (20.9%) in the age category of 13-15 years, and 502 (64%) in the age category of 15-19 years. There were 24 participants with ECG abnormalities in the age category of 10-12 years, while the other two categories combined (i.e., ≥13 years of age) had 20 participants (i.e., a relative risk of 6.773 (confidence interval [CI] 3.868-11.859) for having an ECG abnormality in the age group of 10-12 years compared to the age group of ≥13 years). The odds ratio was 8.247 (CI of 4.385-15.509).

Similarly, when the ≥16-year age group (n = 502) was compared with the other two age groups combined (i.e., 10-15 years, n = 282), there were 11 ECG abnormalities and 33 ECG abnormalities, respectively. This gives a relative risk of 5.340 (CI 2.742-10.401) for showing ECG abnormality in the age group of 10-15 years compared to ≥16-year age group. The odds ratio between the same groups was 5.916 (CI 2.940-11.903).

A notable feature is that the age group 10-12 has a higher relative risk of an abnormal ECG finding compared to other age groups. This could have happened because of the overall smaller number of athletes requesting fitness medicals.

Analysis of past literature, including the work of De Noronha et al. 2009,^[7] and the researcher’s personal experience highlight three critical factors that substantially elevate the predisposition to heart conditions:

1. A significant familial history of cardiovascular disease

2. The existence of additional coronary risk factors

3. Symptoms that strongly indicate the presence of heart disease.

The main drawback is the lack of similar studies conducted in Sri Lanka or globally that directly align with the specific population and focus of our research. This absence of comparable studies underscores the novelty of our work and its potential to fill a critical gap in the existing literature.

While global studies frequently report a higher prevalence of cardiovascular abnormalities (ranging from 5% to 10% depending on the population, types of sports being considered, and screening methods), the lower prevalence in Sri Lanka may reflect differences in screening protocols rather than actual incidence. The reliance on basic diagnostic methods, such as physical examinations and selective use of ECG, contrasts with more resource-intensive approaches seen in high-income countries, where echocardiography and advanced imaging are often employed.

The observed prevalence in Sri Lanka also highlights a narrower focus on endurance sports compared to global studies that often evaluate a wider array of athletic disciplines. For example, contact sports such as American football and rugby, which dominate studies in North America, carry their unique cardiovascular risks due to the intense physical strain and potential for trauma. In contrast, the predominance of running in Sri Lanka’s athletic profile provides insights into how specific sports influence cardiovascular risks.

One major similarity lies in the age-related findings. Both global and Sri Lankan studies indicate that younger athletes, particularly those in early adolescence, exhibit higher rates of ECG abnormalities. This underscores the importance of initiating cardiovascular screening early in an athlete’s career to ensure timely identification and management of potential risks. Differences also emerge in the resources and infrastructure available for cardiovascular evaluations. High-income countries often implement more comprehensive PPE protocols, including access to portable ECG devices, advanced imaging technologies, and specialized personnel. In contrast, Sri Lanka’s resource limitations mean that screenings are less comprehensive, potentially leading to under-diagnosis of certain conditions.

Recommendation

The findings of this retrospective study align closely with those of other research conducted on the subject. Considering the evidence, the following recommendations are proposed:

Suggestions for future research

To further prevent sports-related fatalities, future research should focus on understanding the underlying causes and mechanisms of sudden death in athletes, with an emphasis on improving screening strategies.

Limitations and strength

Limitations include getting the ECG for all mandatory sports before PPE. Government hospitals prioritize ECG testing for patients over testing for athletes. The primary strength of the study lies in its analysis of a larger cohort of athletes in many different age groups in several different kinds of endurance sports. There could be the researchers’ bias while interpreting the ECG. Some of the pathological ECG changes might not appear at the time of test. The history given by the athlete and the filling of the questionnaire may have false information.