Sex differences in ECGs of trained athletes: A systematic review and meta-analysis

Aims: To describe and quantify sex differences in the screening electrocardiograms (ECG) of athletes. Method: Five databases (MEDLINE, EMBASE, Scopus, SPORTDiscus and Web of Science) were searched from inception until October 2024. Included studies were original research articles examining athletes aged 16-40 years, who had a 12-lead screening ECG, and where analysis was stratified by sex. Risk of bias was assessed using a validated tool. A meta-analysis was performed, using a random-effects model, assessing proportions of athlete normal, borderline and abnormal ECG features (according to the 2017 International Criteria) and several ECG measurements. Results: Eighty-five cross-sectional studies were included. The studies comprised 19,069 female athletes (mean age 20.6±2.8 years) and 57,745 male athletes (mean age 21.3±3.1 years). Female athletes were more likely to have abnormal T-wave inversion (TWI) (OR 2.3, 95% CI: 1.5-3.5), and isolated TWIV1-V3 (OR 5.6, 95% CI: 3.2-9.9) compared to males. No female athletes and two male athletes with isolated TWIV1-V3 were diagnosed with a condition associated with sudden cardiac arrest or death (both male athletes diagnosed with arrhythmogenic cardiomyopathy). Female athletes were also more likely to have an abnormal ECG per the International Criteria, though the finding was not statistically significant (OR 1.3, 95% CI: 0.7-2.4). Female athletes had a 16ms (95% CI 4-27ms) longer QTc interval than male athletes. Conclusion: Compared to male athletes, female athletes were twice as likely to have abnormal TWI and six times as likely to have isolated TWIV1-V3, a finding which was not accompanied by diagnoses of cardiac pathology in female athletes. These data should help inform sex-specific aspects of athlete ECG screening guidelines.