Vaccination outweighs risk of myocarditis and other heart issues, cardiologist says

Canadian soccer star Alphonso Davies' return to his German club Bayern Munich was put on hold. The reason: inflammation of the heart muscle.

Davies contracted a mild form of myocarditis after a bout of COVID-19, according to the team.

Myocarditis is the inflammation of the heart muscle and pericarditis is the inflammation of the heart lining. Both have been observed as a result of viral infections, and early in the pandemic, cardiologists started to see reports of them in COVID-19 patients. They have also been listed as rare side effects of the mRNA Pfizer and Moderna vaccines.

The risk for either is not great, according to multiple studies, the U.S. Centers for Disease Control and Prevention (CDC), and Health Canada.

"It wasn't a large number of patients, but definitely there was some association and it was published, and subsequently, many other publications came along and confirmed that COVID infection can, in fact, cause myocarditis," said Dr. Vartan Mardigyan, a cardiologist who runs the Jewish General Hospital's Pericardial Diseases program.

COVID-19, Mardigyan said, primarily affects the lungs and damage to the heart remains rare, according to medical journal registries in the U.K., Israel, the U.S. and elsewhere.

The same, he said, can be said about the Pfizer and Modern vaccines.

"Similar type of phenomenon, but at a lower incidence," said Mardigyan. "It's specific to those vaccines. And both of those vaccines have about an incidence of 10 cases per million... Of those cases, 95 per cent of them are like very mild cases that subside on their own."

Mardigyan added cardiologists are seeing fewer cases of myocarditis related to other viruses that usually cause it, so the rate of infection remains the same.

"There's less flu going around, there's less than the other viruses, so the actual incidents in what we're seeing in clinics and hospitals, we're not seeing more myocarditis cases," he said.

The age group most affected is young men. Davies is 21 years old, and square in the middle of the demographic.

The Canadian National Advisory Committee on Immunization (NACI) said to mitigate the risk of myocarditis or pericarditis, a smaller Pfizer-BioNTech dose is recommended for those 12 to 29 years old and an eight-week interval is recommended between the first and second dose. The same goes for the booster shot.

1 IN 50,000 DOSES

Health Canada said myocarditis and/or pericarditis has been reported in around one in 50,000 (0.002 per cent) doses administered.

Health Canada continues to say vaccination benefits outweigh the risks.

"Infection with the virus that causes COVID-19 is linked to a wide variety of complications that can result in hospitalizations and/or death," the health agency wrote in a statement last month. "Myocarditis is one of the known complications of COVID-19 infection, with much higher risks after infection than after vaccine."

The CDC issued a report Tuesday after reviewing reports to the Vaccine Adverse Event Reporting System (VAERS) between December 2020 and August 2021, and found that "myocarditis was identified as a rare but serious adverse event that can occur after mRNA-based COVID-19 vaccination, particularly in adolescent males and young men."

"However, this increased risk must be weighed against the benefits of COVID-19 vaccination," the report reads.

A study out of Hong Kong published in the Annals of Internal Medicine journal found similar conclusions looking at the Pfizer vaccine and the Chinese developed CoronaVac vaccines.

Mardigyan said when he talks to patients, at times they fear side effects, but assures them that vaccination benefits will far outweigh the risks.

"I often feel like part of the reason is because they have a disproportionate perspective of what the actual risk is," he said. "If you look at the consequences of getting COVID of lung issues, myocarditis and all the other things that can be related to COVID, there's no doubt about the benefit of getting the vaccination."