• Posted February 25, 2025

Study Finds No Spike in Cardiac Arrest in Athletes During Pandemic

A new study has found no evidence that COVID vaccines increase the risk of sudden cardiac arrest in young athletes, despite numerous claims that circulated during the pandemic.

The six-year study — published Feb. 24 in JAMA Network Open — compared sudden cardiac arrests and deaths among competitive athletes aged 10 and older before and during the pandemic. Cardiac arrest is when the heart suddenly stops beating.

"This cohort study found no increase in [sudden cardiac arrest or sudden cardiac death] in young competitive athletes in the US during the COVID-19 pandemic, suggeting that reports asserting otherwise were overestimating the cardiovascular risk of COVID-19 infection, vaccination, and myocarditis," researchers wrote.

They found 203 cases from 2017 to 2019 and 184 cases from 2020 to 2022, showing no spike after vaccines became available.

“I think the results speak for themselves. There was really no change in the overall frequency of sudden cardiac arrest and death in young athletes across the U.S.,” study author Dr. Jonathan Drezner, director of the Center for Sports Cardiology at the University of Washington, told NBC News.

The study challenges misinformation spread during the pandemic, including claims that COVID vaccines caused athletes to collapse.

In 2021, a viral video set to ominous music and posted on a website of an internet talk show founded by anti-vaccine activist Del Bigtree showed athletes collapsing during games, NBC News reported. 

The Buffalo Bills' Damar Hamlin’s cardiac arrest in 2023 and Bronny James' collapse later that year fueled more speculation.

Experts stress that these claims were never based on real science.

"[This study should] make it clear to everyone, even naysayers, that Covid was not a particularly difficult virus for young, healthy people, and that the vaccine did much more good than harm,” Dr. Aaron Baggish, a cardiologist at the Massachusetts General Hospital Heart Center, who was not involved in the study, said.

Cardiac arrest in young athletes is rare and is usually linked to underlying heart conditions like genetic disorders or birth defects, rather than vaccines or viruses.

The study noted that 30% of cardiac arrests happened outside exercise.

Dr. Neel Chokshi, medical director of Penn Medicine’s Sports Cardiology and Fitness Program, called that unsurprising. 

“We’ve noticed that oftentimes ... it’s not during actual exercise or strenuous activity, but it can happen at any time,” said Chokshi, who was not involved in the study. 

More information

Johns Hopkins Medicine has more on cardiac arrest.

SOURCES: JAMA Network Open, Feb. 24, 2025; NBC News, media report, Feb. 24, 2025