Better ECG Interpretation Criteria Needed for Professional Basketball Players, Study Suggests

ECG abnormalities detected as part of a cardiac screening program mandated by the National Basketball Association (NBA) were found in 15.6% of active players and potential draftees, a new analysis shows. This suggests not that there is a high rate of dangerous health problems in the league but rather that ECG interpretation criteria need to be better refined to reflect normal structural changes that accompany intensive training in professional athletes.

“When we compare the ECG data with matched echocardiographic data, we see that their hearts are actually normal and these abnormal ECGs are false-positive ECGs,” senior author David Engel, MD (NewYork-Presbyterian/Columbia University Medical Center, New York, NY), told TCTMD, noting that no cases of structural heart disease were found.

“It shows that the ECG in isolation is not necessarily a perfect test to be used for screening basketball players,” he added. “If you’re going to do systematic screening of basketball players, you may need to . . . do other imaging tests, especially an echocardiogram, so that you can really put the ECG findings into context.”

The study was published online today ahead of print in JAMA Cardiology.

Elevated Risk of Sudden Cardiac Death in Basketball Players

ECG interpretation is complicated in athletes, Engel explained, because it can be difficult to distinguish between findings tied to normal cardiac structural changes stemming from training and those caused by pathological conditions like hypertrophic cardiomyopathy and other cardiac abnormalities.

For that reason, there has been a series of athlete-specific ECG interpretation criteria released over the past several years. Each iteration has improved the accuracy of identifying normal versus abnormal findings according to studies conducted diverse athlete populations, but they are not specific to any one sport, Engel said.

He added that the issue of accurately interpreting ECGs is particularly important for basketball players because of a much higher rate of sudden cardiac death in this group than in the general population. That understanding prompted the NBA to implement mandated, league-wide cardiac screening and monitoring—done in conjunction with NewYork-Presbyterian/Columbia University Medical Center—that involves ECGs and stress echocardiograms performed yearly for active players and before entry into the league for prospective players.

Investigators developed a core laboratory for the league and now maintain all of the findings in a centralized database. Engel, lead author Marc Waase, MD, PhD (NewYork-Presbyterian/Columbia University Medical Center), and colleagues tapped into that trove of data to see how well the most recent ECG interpretation criteria—the “international” criteria published earlier this year—work in professional basketball players.

The analysis included 404 active players during the 2013-2014 and 2014-2015 seasons and 115 participants in the combines used to evaluate prospects before the league’s drafts in 2014 and 2015. Overall, 78.8% of the players were African-American, 18.5% were white, and the rest were other races/ethnicities. Mean age was 24.8 years.

Physiologic, training-related ECG changes were detected in 89.0% of athletes; the most prevalent was early repolarization (69.7%).

ECG abnormalities defined by the international criteria were found in 15.6%, and their presence was strongly related to increasing age and LV relative wall thickness on echo. Body size and race/ethnicity were not related to the presence of abnormalities, however.

The most common abnormality was abnormal T-wave inversion (TWI), found in 6.2% of players. That finding correlated with a smaller LV cavity size and greater LV relative wall thickness, which “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.

Sport-Specific ECG Interpretation Criteria

Engel said the study provides a frame of reference for interpreting ECG findings in basketball players and “suggests that the existing criteria might need to be individualized for the sport.”

In an invited commentary accompanying the paper, Sanjay Sharma, MD (St. George’s, University of London, England), says the study “is an important contribution to sports cardiology. It emphasizes the need for more detailed investigation in larger cohorts of black athletes to ascertain whether assessing the pattern, depth, and/or width of inferior/lateral TWI might help predict more precisely which black athletes might be at risk of cardiac disease or death.

“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,” he continues, adding, “Until further data are available, it would be prudent to routinely investigate black athletes with inferior and/or lateral TWI for cardiomyopathy.”

Engel said that his group is currently performing a similar analysis in the Women’s National Basketball Association and is collecting serial data from the cardiac screening program to see whether there are any changes over time that may provide insight into the significance of abnormal ECG findings.