Outcomes of 10 years of cardiac screening of elite New Zealand athletes
Authors: Orchard J , Orchard J W , Davis A J , Puranik R , Isbister J , La Gerche A , Driscoll T , Doughty R N , Hamilton B 
Published: November 2023

Abstract

Background/Introduction
Cardiac screening of competitive athletes for conditions associated with sudden cardiac death is recommended by bodies including the European Society of Cardiology. High Performance Sport New Zealand (HPSNZ) commenced cardiac screening of elite Olympic sport athletes in 2012.

Purpose
To report the 10 year outcomes and findings of the HPSNZ cardiac screening program, including comparisons of electrocardiogram (ECG) features between sexes, sports and ethnicities.

Methods
Athletes were screened by HPSNZ from February 2012-June 2022 in accordance with HPSNZ protocols and as required by their International Federations. Screening included a personal/family history, physical examination and resting 12-lead ECG (interpreted by a cardiologist experienced in athlete ECGs), and athletes were followed for up to 11 years. Clinical findings and ECGs were managed contemporaneously as required. In July 2022 all screening records, including demographic data, ECGs, follow-up testing and diagnoses were reviewed. Although ECG guidelines changed during the period, any abnormal/equivocal ECGs were re-reviewed using the International Criteria. Comparisons between groups were performed using Fisher’s exact test (2-sided, p&lt;0.05 considered significant).

Results
2075 ECGs from 1189 athletes (53% female, mean age 21 years; 83% European, 14% Māori and Pacific Islander, 3% other ethnicities) were included. Major diagnoses included Wolff-Parkinson-White (WPW) syndrome (0.7%) and cardiomyopathies (0.3%). Overall, 3.5% of ECGs were abnormal (International Criteria). ECGs of female athletes were more frequently abnormal (4.4% vs 2.5%, p=0.02) and had more abnormal T-wave inversion (TWI) (3.1% vs 0.9%, p=0.0005) compared to males. 47% of the abnormal TWI in females was limited to V1-V3 with no other ECG abnormalities. There were no differences in the proportion of abnormal ECGs between the highest intensity/endurance sports and other sports, nor between Māori and Pacific Island athlete ECGs compared with European (Table 1). No athletes retired for cardiac reasons, there were no cardiac deaths nor major cardiac incidents during the period (mean follow up from first screening: 73 months). There was a significant reduction in follow-up tests recommended after the introduction of the International Criteria.

Conclusions
WPW was the most frequent diagnosis, with very little cardiomyopathy found in this cohort. The proportion of abnormal ECGs was low overall, and lowest after the introduction of the most recent athlete ECG guidelines, likely reflecting enhanced specificity. ECGs of female athletes were more frequently abnormal, predominantly because of anterior TWI V1-V3, which potentially could be considered a normal finding in elite female athletes. We report for the first time a comparison between Māori/Pacific Island athletes and European athletes, showing no difference in the proportion of abnormal ECGs, although further data are needed.