The international criteria for electrocardiography (ECG) interpretation in athletes perform better than prior iterations in predominantly African American National Basketball Association (NBA) players, but the false-positive rate is still relatively high in these elite athletes, a new study suggests.
Among 519 NBA players (78.8% African American) with no structural disease on preseason echocardiographic testing, abnormal ECG findings were identified in 25.2% by using the 2013 Seattle criteria, 20.8% by using the 2014 refined criteria, and 15.6% by using the 2017 international criteria.
"The false positive rate in white athletes is now only 3%, but we still have a way to go with black athletes," he said. "This is because 6% have inferior T-wave inversion and 4% have lateral T-wave inversion."
Sharma noted that false-positive rates reached almost 40% in black athletes screened with the 2010 European Society of Cardiology recommendations, which were derived from a group of white, predominantly amateur Italian athletes and considered T-wave inversion (TWI), axis deviation, atrial enlargement, and right ventricular hypertrophy as ECG anomalies that warranted further tests.
Since then, large studies have shown that TWI in the anterior leads (V1 to V4) are normal variants in black athletes and are usually preceded by ST-segment elevation. Other studies have also shown that axis deviation, atrial enlargement, and right ventricular hypertrophy are normal variants in all athletes.
At baseline in the present study, the 519 NBA players had a mean age of 24.8 years (the oldest group was age 27 to 39 years; the youngest group was age 18 to 22 years), a mean height of 199.9 cm, and a mean body surface area of 2.37 m2.
White athletes were older than African American athletes and had a higher mean body surface area, while African Americans were more likely to have two or more training-related ECG findings (66% vs. 49%), including early repolarization (72.6% vs. 58.3%).
The results, published recently in JAMA Cardiology, showed no significant relationship between abnormal ECG findings and race, athlete height, body surface area, or left ventricular (LV) mass or cavity size.
Abnormal ECG findings, however, were significantly more common in the oldest vs the youngest athletes and in those in the highest vs lowest tertile for LV relative wall thickness (RWT). Abnormal TWIs were present in 6.2% of athletes but did not differ significantly by athlete race, age, height, body surface area, or LV mass.
"This finding emphasizes the importance of these factors of left ventricular geometry and this particular left ventricular concentric geometric pattern, which appears to have a significant influence on the surface ECG," the authors write.
"The association of concentric left ventricular remodeling or hypertrophy with inferior and/or lateral TWI raises the question of whether left ventricular hypertrophy induced by sports in black athletes might be a harbinger for serious arrhythmias, as is the case in black patients with hypertensive heart disease," Sharma reports.
This is pertinent, he says, because exercise-associated sudden cardiac death (SCD) has been shown to be far more common in predominantly black National Collegiate Athletic Association (NCAA) Division I male basketball players than in NCAA athletes overall.
He notes that the present study lacked information on blood pressure readings, use of performance-enhancing agents, and how comprehensively the athletes were investigated to exclude the broader phenotypic spectrum of hypertrophic cardiomyopathy.
Finally, DiFiori agreed that further research is needed and said the present results were based on a unique population of elite athletes. As a result, they aren’t necessarily generalizable to other age groups or other athletes with different anthropomorphic characteristics.
Still, the study should give some people pause about simply using an ECG as a screening tool as has been suggested to target at-risk athletes, particularly at the NCAA level.