New findings could help protect elite athletes from cardiac arrest

A new study involving 281 elite athletes from Australia and Belgium has revealed one in six have measures that would normally suggest reduced heart function. The study conducted by scientists at the St Vincent’s Institute of Medical Research in Melbourne and the Victor Chang Cardiac Research Institute also discovered this same group of athletes had a genetic predisposition to the reduction in heart function. The first-of-its-kind study included winners of the world’s top cycling races – and could one day lead to elite athletes being genetically tested to prevent them from suffering from sudden cardiac arrest.

Journal/conference: Circulation

Organisation/s: Victor Chang Cardiac Research Institute (VCCRI), St Vincent’s Institute of Medical Research (SVI)

Funder: This work was supported by the National Health and Medical Research Council of Australia (APP1130353), Baker-Royal Melbourne Hospital Seed Grant, Heart Foundation of Australia, Australian Cardiovascular Alliance/Bioplatforms Australia Research Catalyst Program, and the Perpetual Impact Philanthropy Program. The ASPREE study was supported by a Flagship cluster grant (including the Commonwealth Scientific and Industrial Research Organisation, Monash University, Menzies Research Institute, Australian National University, University of Melbourne); and grants (U01AG029824 and U19AG062682) from the National Institute on Aging and the National Cancer Institute at the National Institutes of Health, by grants (334047 and 1127060) from the NHMRC, and by Monash University and the Victorian Cancer Agency. Dr Lacaze is supported by a National Heart Foundation Future Leader Fellowship (102604).

Media release

From: Victor Chang Cardiac Research Institute (VCCRI)

A new landmark study involving 281 elite athletes from Australia and Belgium has revealed one in six have measures that would normally suggest reduced heart function.

Genetic analysis revealed that those athletes also had an enrichment of genes associated with heart muscle disease. Thus, a genetic predisposition may be ‘stressed’ by exercise to cause profound heart changes. The long-term consequences will continue to be evaluated in this international collaboration.

Associate Professor Andre la Gerche, who heads the HEART Laboratory that is jointly supported by St Vincent’s Institute in Melbourne and Victor Chang Cardiac Research Institute, says the findings highlight the need for far closer monitoring of the heart health of elite athletes and could one day lead to genetic testing being part of health screening.

A/Prof La Gerche says: “We have long known that elite athletes have hearts very different from those of the general population. Exercise promotes profound heart changes.  The heart is large in all elite athletes, but there is still considerable variation ranging from large to enormous. The long-term significance of the most extreme changes is not yet certain.”

“We discovered that one in six athletes had reduced heart pumping action, as well as showing for the first time the role genetics plays in heart function in these athletes. We must monitor these athletes over the long term to see the long-term impact on their health, which is still to be played out.

“We want to keep our athletes healthy and prevent them from suffering a cardiac arrest. The better we understand the athletes’ heart, the more we will be able to identify risks in advance of tragedy.”

The team of international researchers have now recruited over 400 elite endurance athletes that includes winners of the world’s biggest cycling races. This analysis of the first 281 athletic men and women was performed using the same state-of-the-art exercise and heart imaging in six cities across Australia and Belgium. The results were published in Circulation.

Key findings

  • One in six athletes (15.7%) had heart measures that fall in a range normally associated with heart disease – including an enlarged heart, irregular rapid heartbeat, and changes in the heart’s left ventricular chamber responsible for pumping blood full of oxygen out to the body.
  • The reduced heart function was only observed when they were at rest. When exercising, the heart functioned at levels known as super normal, which means their hearts could substantially increase the pumping action when needed to boost cardiac output.
  • Athletes were also genetically screened to discover if they had genes associated with developing dilated cardiomyopathy (DCM). Those elite athletes with the highest genetic load were 11 times more likely to have a reduction in heart function measures.

Professor Diane Fatkin, of the Victor Chang Cardiac Research Institute, who undertook the genetic analysis of the athletes alongside Associate Professor Eleni Giannoulatou, said this study was the first in the world to look at the role of genetics in susceptibility to DCM in athletes.

“The phenomenon of the athletes’ heart has long been known, but we were the first team to investigate an athlete’s genetic makeup in their heart function and structure. We have found that there are far more profound changes than thought and that a high number of these athletes have altered heart function,” said Professor Fatkin.

“It’s very important we don’t think of these athletes as having sick hearts because they can still function at a very high level. But we don’t know what the long-term effect will be and if this means these athletes will go on to develop cardiomyopathy.”

A/Prof La Gerche says it is now vitally important to follow this same group of athletes over the next 25 years to see if they do go on to develop DCM.

“Regular exercise is associated with clear health benefits, but maybe there is a small group with a genetic predisposition in whom that benefit is less. It might even be potentially dangerous for them to exercise at this incredibly high level,” says A/Prof La Gerche.

“Our overall hope from this research is that we can make all sport safe for all participants. Understanding the interplay between genetic traits and high-dose exercise is a step towards this goal”.

SOURCE

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