Myocarditis: Covid-19’s hidden risk?
Even athletes who’ve recovered from a mild bout of Covid-19 are sustaining heart damage according to recent academic research. It’s dividing opinion about the danger the virus poses to the young, fit and healthy.

The recent publication of a research paper by JAMA Cardiology is creating lively debate about the risk and prevalence of the heart disease, myocarditis, among young athletes who’ve recovered from Covid-19.

It’s an important issue not only for the athletics community but also the wider population at large given how many young people believe that contracting Covid-19 will not make them ill, or leave them with any lasting health issues.

Myocarditis, is a form of heart inflammation and is one of the most challenging conditions for cardiologists to diagnose. Viruses are a well-known cause, although most people recover from it without ever knowing they’ve had it in the first place.

But it is particularly dangerous for sportsmen and women because intense exercise puts additional pressure on the heart, potentially leading to cardiac arrest if there’s undiagnosed inflammation. American magazine, Sports Illustrated, says that myocarditis accounted for 2% to 5% of sudden deaths per annum in US sports before the pandemic.

The large numbers of people who have contracted Covid-19, especially in the Western world, potentially exposes a larger than normal number of unwitting athletes to cardiac issues.

The study, published this September, analysed 26 US college level athletes in Ohio State who’d had a mild or asymptomatic case of Covid-19. Their mean age was 19.5 and 57.7% were male.

They found that four athletes had evidence of myocarditis based on two indicators: elevated troponin I (a heart protein that’s released into the blood if the heart is damaged) and; nonischemic LGE (a sign of scar tissue which can be seen on MRIs). A further 12 had nonischemic LGE alone.

However, both issues were only discovered after the athletes had received cardiac MRI scans (magnetic resonance imaging). Their electrocardiogram and echocardiogram results had come back normal. The former analyses the heart’s electrical activity and the latter checks whether the muscle and valves are working normally.

The research builds on earlier studies, which have shown the damage, which Covid-19 can inflict on the heart. This is because of the cytokines, which the immune system releases to clear the virus out from heart cells. If the immune system overreacts, the heart gets damaged.

However, the problem is that most people don’t get an MRI scan after they’ve had a virus, so researchers don’t know how widespread the issue was before the current pandemic.

The researchers behind the Ohio State study suggest that MRI scans could be used to identify high-risk athletes. However a few weeks later, a group of 50 scientists published an open letter pointing out that the study was based on a limited data set and that it is unclear if the MRI findings flagged in these studies are clinically significant.

They were worried that the media coverage such studies are receiving are also generating high levels of anxiety that might have worse longer-term implications than the inflammation itself, which could clear up of its own accord. They don’t want people to stop exercising and are concerned about the number of people seeking MRI scans without any evidence of cardiac symptoms.

A second JAMA Cardiology study published in late October struck a similar theme. Researchers from the Massachusetts General Hospital and Emory University School of Medicine pointed out that, “bouts of exercise in individuals in good health often leads to a transient elevation in troponin levels and short-term imagining findings suggestive of cardiac fatigue including myocardial inflammation.”

They also said that 36% of the patients in another German study (that had similar results) had existing preconditions including diabetes and hypertension, which might explain their MRI findings rather than Covid-19.

Their conclusion: athletes that have had a mild or asymptomatic case of Covid-19 do not need an MRI scan, adding that, “while concerns about the implications of cardiac injury attributable to Covid-19 infection deserve further study, they should not constitute a primary justification for the cancellation or postponement of sports.”

Nevertheless, that does not mean that people should not be aware of the warning signs of myocarditis. These include shortness of breath, an abnormal heartbeat, fainting, light-headedness, and painful or swollen joints. They all warrant a visit to the doctor.

Standard treatments after a diagnosis of myocarditis include ACE inhibitors, which widen blood vessels, beta blockers, which slow the heart down and diuretics, which aid the kidneys and help the heart to pump. Bed rest is also important and for athletes, cardiologists typically recommend staying off intense physical exercise for three to six months.


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