Without that information, it’s hard to know what to make of the Frankfurt COVID-19 study or others like it. Yes, some patients have myocarditis—but what does that mean? How do the numbers compare to other respiratory viruses? Will COVID-19 patients with myocarditis recover fully, or will some have long-term problems? Is this virus doing something strange, or are researchers just studying it more intensely than other viral infections? For now, it’s difficult to say.
The worry is that COVID-19 is doing whatever it’s doing at scale. The original SARS epidemic of 2003 infected only 8,000 people, killed slightly fewer than 800, and was over in three months; its impact on the heart was “lost in the historical bin of the scientific literature,” says Checchia. SARS-CoV-2, by contrast, has infected at least 31 million people and killed at least 960,000. Its effects are thousands of times more obvious than its predecessor’s. Even if it’s no worse than any other viral illness, its sheer scope means that a tiny risk of severe long-term problems would still translate to a lot of failing hearts.
Reassuringly, “there hasn’t been an obvious influx of patients being admitted to the hospital with unexplained myocarditis, despite the huge numbers who have had COVID-19,” says Venkatesh Murthy, a cardiologist at the University of Michigan. “I don’t find it convincing that there is a major amount of serious clinically relevant myocarditis in people who are feeling well.”
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Still, he and others say that long-term studies are important. “We’re still early,” says Chen. “I don’t think there’s a defined time point when we’d expect to see heart failure, so we have to follow these patients for months or years down the road.”
That can be unnerving for people who are currently sick. Long-haulers, who are struggling with months of debilitating COVID-19 symptoms, are “responding to the media’s interpretation of these studies and, to put it bluntly, are rightfully freaking out,” said Kontorovich, who is part of a team that provides care for long-haulers. But for now, she sees the myocarditis issue and the long-hauler phenomenon as separate matters.
Some long-haulers have been diagnosed with dysautonomia—a group of disorders that disrupt involuntary bodily functions, including heartbeats (which can become inexplicably fast) and blood pressure (which can suddenly crash). But people who have lingering heart problems after viral myocarditis don’t usually experience the chronic symptoms that long-haulers do, and they typically have measurable changes to their hearts that long-haulers don’t. “There may be a connection, but it hasn’t been proved,” Kontorovich said.
College athletes are also facing immediate decisions. In just the past two months, the 27-year-old basketball player Michael Ojo died from a heart attack during a practice, while the 20-year-old football player Jamain Stephens Jr. died from a blood clot in his heart. Both had previously contracted COVID-19.