Spotting Risk: Cardiac Screening Essentials in Athletes

This transcript has been edited for clarity. 
My name is Dr Jonathan Kim. I direct sports cardiology at Emory University and Emory Healthcare. I’m also the current chair for the American College of Cardiology’s Sports and Exercise Cardiology Council. I’ve been asked to talk about the important topic of sudden cardiac arrest and death in athletes. This is a topic that everyone takes very seriously, and the reason is, when you think about a competitive athlete, you generally think of an individual who embodies optimal health. 
Unfortunately, if there’s a tragic event and an athlete suffers sudden cardiac arrest during exercise or playing a competitive sport, this generates a visceral response among all of us. “How could this possibly happen? How often does this occur? What are the common causes? How can we prevent such events? If an athlete suffers sudden cardiac arrest and they, thankfully, survive, can they actually get back to playing competitive sports?” We’re going to talk about all of these very important topics. 
Let’s begin with the first question. “How common is this?” Available estimates are imprecise because of limitations in the literature. The limitations exist because, in the United States, we don’t have a uniform mandatory reporting system of cases of sudden cardiac death. 
As a result, there can be flaws in the data that report these types of events. “What’s the study design?” A retrospective study design has limitations. “How do you identify all the right cases? How do you know you’ve identified all the right cases?” That’s the numerator. What about the denominator? What group are you specifically looking at in terms of different competitive athlete groups? 
Although we don’t have precise estimates, what is reasonable to say is that these cases are overall uncommon, thankfully. That’s why subtle changes in how you define either the numerator or the denominator can actually make very dramatic differences in terms of the reported prevalence or incidence. 
“What are the specific etiologies?” This is very clear-cut. Etiologies are very much age dependent. For the young athlete, which we define as athletes who are under 35 years of age, cases will generally fall into one of three different categories. 
It could be a structural heart problem or cardiomyopathy, which are genetically inherited heart conditions. The perfect example is hypertrophic cardiomyopathy, and another example is arrhythmogenic cardiomyopathy. 
Is it a primary arrhythmia, one of the primary inherited arrhythmia syndromes? The classic example here is long QT syndrome. 
The third and final category includes acquired cardiac abnormalities, and the classic example here is myocarditis, where there’s inflammation in the heart. This generally occurs after an infectious process. 
For the older athlete, which we define as 35 years of age or older, the most common cause is underlying coronary artery disease. When a case occurs in any age group, it does require a very comprehensive evaluation, which is generally driven by a sports cardiologist in collaboration with other specialists, such as an electrophysiologist or interventional cardiologist, to potentially identify one of these specific diagnoses. 
One question that comes up frequently is, “What’s the most common cause of sudden cardiac death in a young competitive athlete?” As I mentioned, for the older athlete, it is usually due to underlying ischemic heart disease. For the younger athlete, at present, it’s most common that you can’t find a cause, where the autopsy for a deceased athlete is normal. We define these cases as autopsy-negative — sudden unexplained death. 
The next question, which really garners most of the attention is, “How can we prevent these cases?” This really begins with primary prevention. This is about screening. “How can we identify a young athlete, who may harbor one of these underlying conditions before a potential catastrophic event occurs?” This is actually the space where there’s a bit of controversy. 
Where we all agree is that screening begins with the 14-point history and physical. This is the opportunity to send an athlete to see a medical professional. For young athletes, this may be the first time they’ve gone to see a physician as young adults. It is really important to get a blood pressure reading and to go through basic cardiac risk factors. 
As it pertains to screening, we’re trying to assess whether there are exertional symptoms during exercise, listening for concerning cardiac murmurs, and most importantly, we go through a very detailed family history to determine whether there’s been a family history of unexplained sudden cardiac death or any of the inherited conditions that I mentioned. 
Where the controversy comes into play is that, from a screening standpoint, the sensitivity of the history and physical is really quite dismal. That sensitivity is improved when you add in a 12-lead ECG. You can potentially identify conditions that aren’t easily identifiable just by asking simple questions. 
There are a few things to consider, however, when you think about the ECG. First, I’d say, is that sensitivity does increase by about 90%. “What are some of the things to consider as to why this isn’t considered a ‘slam dunk’ and therefore a test we should do with every athlete here in the United States?” 
First, you have to remember that there are some conditions that an ECG can’t pick up, such as problems with coronary artery origins, what we call anomalous coronary arteries; problems with the aorta; problems with the heart valves; and, of course, myocarditis, because many times, an athlete is screened before they could be afflicted with myocarditis. 
A 12-lead ECG isn’t going to pick up everything. Where the challenge really comes into play is that you have to have the appropriate expertise. Remember, if you’re going to do more testing, it’s ultimately going to lead, potentially, to more tests and referrals. You have to have the right expertise. 
Who is interpreting that 12-lead ECG? Perhaps the most important thing is to have a cardiologist who’s interpreting an athlete’s ECG who’s familiar with the criteria that you should use when you read an athlete’s ECG. That’s called the international consensus for the interpretation of the ECG in athletes. 
In addition, you have to think about downstream resources. We have to make sure that we have equitable outcomes for all athletes. Unfortunately, not all athletes come from neighborhoods where resources are equitable. What’s important to note is, even when you look at the 2017 International Consensus, there is almost double the prevalence of false positives for ECG readings of self-identified Black athletes. If you’re screening a large number of athletes, particularly for those athletes who come from underserved neighborhoods, an inaccurate reading could actually lead to further marginalization that already exists within this community. 
Those are the things that have to be considered. To recap, I would say — this is my opinion — that screening ECGs are certainly reasonable because we know we’re going to pick up more conditions. Ultimately, that’s really going to improve the medical care if you can identify risk factors that require focused cardiac care. But you should only integrate ECG screening if you have thought carefully through these processes. You have to make sure the right people are reading the ECG, and you have to make sure those resources I previously mentioned, with regard to ensuring racial equity, are intact. 
Where we have no disagreement, when we talk about this subject among experts, is secondary prevention, and this is the emphasis on the emergency action plan, or EAP. If you’re going to be involved with organized athletics, you have to make sure that the EAP is in place. I’m specifically talking about the cardiac EAP. This plan begins with immediate recognition of sudden cardiac arrest. You have to know what it looks like. 
Then there has to be immediate implementation of CPR. Of course, that means there has to be emphasis on CPR training and education. There has to be immediate access to defibrillation as well, for those rhythms that require defibrillation. These are all the core tenets of the EAP. It’s also important to emphasize that the EAP has to be practiced, it has to be reviewed at least on an annual basis, and certainly edited, if that’s required. That’s part of the primary and secondary prevention part of the equation. 
Finally, “If an athlete survives a sudden cardiac arrest event, can they return to competitive sports?” The answer is maybe. This athlete still has to undergo very comprehensive diagnostic algorithms. You have to know what the diagnosis is, what caused the event. That condition has to be risk-stratified appropriately. Appropriate treatments have to be implemented. 
Then you have to proceed with what we call shared decision-making. Bring in all the stakeholders and include the athlete as well. What they want is certainly most important, and some athletes may not want to go back to sports. Their families have to be involved as well as the physicians, and then, of course, any other stakeholders. All of these parties have to work together to come up with a decision that potentially could include a return to competitive sports. 
I could have spent at least an hour on all of these topics, but I just wanted to touch on some of the core topics within this space of sudden cardiac arrest in competitive athletes. Thank you so much for listening.