Two researchers found that more than 1,500 athletes have suffered cardiac arrest since COVID-19 vaccinations began, compared to a previous average of 29 athletes per year, suggesting the vaccines are causing a dramatic rise in such cardiac issues.

The researchers cited a number from a blog that lists news stories about recent deaths and medical emergencies among people of all ages, from all over the world — some of which were attributed to other causes.

Following Buffalo Bills safety Damar Hamlin’s cardiac arrest during a game Monday, social media posts and Fox News gave air to a long-circulating and faulty narrative that COVID-19 vaccines are causing a dramatic increase in athlete deaths.

“Cardiologist Peter McCullough and researcher Panagis Polykretis looked into this trend in Europe, European sports leagues.

They found that prior to COVID and the COVID-19 vaccines there were roughly 29 cardiac arrests in those European sports leagues per year,” Fox’s Tucker Carlson claimed in a segment Tuesday. “Since the vax campaign began, there have been more than 1,500 total cardiac arrests in those leagues and two-thirds of those were fatal.”

Carlson was in fact referencing a letter, not a rigorous study, that McCullough and Polykretis published in a Scandinavian journal in late 2022. And that letter simply cites the blog goodsciencing.com.

The blog’s list is a compilation of news reports about recent deaths and medical emergencies, and it includes cases not reported to be spurred by cardiac arrest: Some deaths, for example, were reportedly from cancer. The list also includes incidents from around the world and among people of all ages — including some in their 70s and 80s — not just athletes in “European sports leagues,” as Carlson claimed.

“It’s not real research,” Dr. Matthew Martinez, director of sports cardiology at Atlantic Health System in Morristown Medical Center, told the AP. “Anybody can write a letter to the editor and then quote an article that has no academic rigor.”

Dr. Jonathan Kim, chief of sports cardiology at Emory University School of Medicine, similarly said of the blog post: “It’s just shocking to use that as a citation.” “It’s scientific garbage, you can’t just pull a bunch of media reports,” he added.

The letter by McCullough and Polykretis goes on to compare the blog’s questionable “1,598″ figure of recent incidents to a 2006 study that found 1,101 reports of sudden cardiac death in athletes over a 38-year period, or an average of 29 per year.

That analysis, however, reviewed literature specifically for reports of sudden cardiac death among athletes under the age of 35.

The study also noted that its findings were limited because cases were likely underestimated.” Dr. Neel Chokshi, medical director of Penn Medicine’s Sports Cardiology and Fitness Program, said it would be “inaccurate” to make conclusions by comparing the 2006 study and the blog’s figures.

“The data presented here does not support the notion that vaccines have caused an increase in sudden death,” he said.

The COVID-19 vaccines from Pfizer and Moderna do carry a rare risk of myocarditis, an inflammation of the heart, though experts and officials say the benefits of vaccination outweigh the risks. Cardiologists have told the AP that they have not observed the dramatic increase in sudden cardiac arrest as alleged on social media.

McCullough and Fox News did not return requests for comment.