National Harbor, MD - US doctors have shown it is possible to use an abbreviated echocardiogram for the screening of young athletes to try to identify those at risk of sudden cardiac death (SCD) [
1].
The echo—which takes 15 images as opposed to the usual 60 to 80—was employed, along with a health questionnaire, physical exam, and ECG, by
Dr Michelle A Grenier (Cincinnati, OH) and colleagues. In a poster presented at the
American Society of Echocardiography (ASE) 2012 Scientific Sessions here last weekend, Grenier reported results from the first 85 young people who were screened, but she told
heartwire that her team has now screened almost 400 athletes using the protocol.
"My objective was to take the standard echo protocol and modify it so that it could be performed in a 10-minute window, just to screen, knowing that it would be less than perfect. We're now doing our fourth set of screenings, and I'm amazed. It works like clockwork; we definitely have the flow now. We can efficaciously screen 200 athletes in a day with echo if we find it's a useful modality."
She adds, however, "I didn't seek to answer the question of whether this is a useful modality; that's a very difficult question to answer. I sought to see whether it was reasonable to add this abbreviated echo, whether it was possible to add it, and whether it was cost-effective." The latter, she said, will require screening about 200 more individuals before there is enough statistical power to answer that question.
Is it practical to perform echoes on everyone?
The screening of athletes for potential cardiac problems is highly controversial, with much disagreement between experts as well as between countries on which protocols should be used. Italy has led the way in screening young athletes before allowing them to compete in sports, and its model includes a physical examination, family history, and screening with a 12-lead ECG.
In the US, the
American College of Cardiology and
American Heart Association limit screening to a physical examination and medical history, whereas the
European Society of Cardiology and
International Olympic Committee recommend using resting 12-lead ECG to detect cardiac abnormalities. The argument against mass screening has been that it is like looking for a needle in a haystack; but recently,
cardiac arrests among very high-profile soccer players—one of whom survived and one of whom died—and the sudden deaths of a young Norwegian swimmer and a Serbian rower have brought the subject firmly into the media spotlight.
Whether to include echocardiography in screening is also a subject of debate; this form of screening is generally reserved for elite athletes. For example, the US National Football League and National Basketball Association perform ECGs and echocardiograms.
Sports cardiologist and screening expert Dr Sanjay Sharma (St George's Hospital, London) told heartwire: "If we are reserving screening for the crème-de-la-crème type athlete—for example, Olympic teams—then I think it's very reasonable to do echocardiography, because it's not a massive undertaking. But if we are going to roll this out to every single person who competes—as the Italians do—then I think it would become very impractical." ECG, he says, "takes about four minutes to perform and seconds to interpret if you know what you are looking at. A good echocardiogram takes 15 to 20 minutes to perform."
Grenier says this is one reason she is trying to develop a shortened echo: "If elite athletes are subject to that sort of testing, our young athletes should be subjected to it as well," she asserts.
Very high number of abnormal echoes
In designing the abbreviated echocardiogram, she explains she took the "standard" protocol for an echo, as stipulated by the ASE, and amended it to include 15 images, including the long- and short-axis views, a four-chamber view, and an ejection fraction, as well as looking at the aortic arch and abdominal aorta. The abbreviated echo allows measurement of myocardial dimensions and function, evaluation of valve anatomy and function, and coronary anatomy, as well as aortic anatomy and flow patterns, and it enables septal defects to be excluded, she says.
The initial 85 athletes—who were aged 14 to 18 years and from local schools, pediatric offices, and athletic clubs—were screened by six sonographers. Echoes were triaged on the spot, with Grenier herself personally reviewing them all. The researchers found a disproportionately high number of individuals with abnormal echoes—10 of the 85 (12%) athletes—who were then referred for further assessment. These individuals all had normal health questionnaires, physicals, and ECGs.
Grenier says that this percentage has dropped to about 8% with further screenings of around 400 athletes but acknowledges "this is still high." She stresses that the abbreviated echo protocol "has undergone several modifications," and it will continue to be tweaked as it undergoes future development. For example, "We are measuring aortic roots as large, and I think that the numbers we are using as baseline may be an underestimate of what normal may actually be."
No false positives; follow-up warranted
Nevertheless, she stresses that of the 85 athletes initially screened, there were "no false positives." Of the 10 athletes who had abnormal echoes, there were four with dilated aortic roots, who received further cardiovascular genetic evaluation; one with a silent patent ductus arteriosus, for which no action was taken; one with an atrial septal defect; and four with left ventricular abnormalities, who were further evaluated at a cardiomyopathy clinic. There were also two additional young people with structurally normal hearts who exhibited long QT.
Two of the 10 athletes (one with LV hypertrophy and one with LV noncompaction) were restricted from competitive athletics based on the echo findings.
Grenier says that the risk of not having detected the abnormalities is unknown. "But we need to follow a lot of these kids over time. It's a snapshot of what their heart looks like, and we don't know how it's going to evolve, but they could potentially run into trouble in the future."
