Heart attack deaths spiked across all age groups in the U.S. since the beginning of the COVID-19 pandemic, according to a study from the Smidt Heart Institute at Cedars-Sinai.

People between ages 25 and 44 are most affected, with a 29.9% relative increase in heart attack deaths over the first two years of the pandemic, according to the study, which was published in the Journal of Medical Virology.

“Young people are obviously not really supposed to die of heart attacks—or even have heart attacks at all,” said Susan Cheng, MD, MPH, director of the Institute for Research on Healthy Aging in the Department of Cardiology and the Erika J. Glazer Chair in Women’s Cardiovascular Health and Population Science at the Smidt Heart Institute.

Other age groups also experienced an increase in heart attack deaths. Deaths increased by 19.6% in adults between ages 45 and 64 and by 13.7% in adults 65 and older.

The spike in U.S. heart attack deaths continued through the Omicron surge, despite that variant of the SARS-CoV-2 virus being associated with milder illness than previous variants. The increases in heart attack deaths have aligned with COVID-19 surges nationwide.

The correlation is more than coincidence, Cheng said, given what’s known about how COVID-19 affects the cardiovascular system. Infection with SARS-CoV-2 appears to affect the stickiness of blood and thus the likelihood of clot formation. Infection with SARS-CoV-2 also increases inflammation in the blood vessels and can cause stress that increases hypertension.

Researchers are not certain why young people are increasingly affected. One theory, said Cheng, is that the virus’ impact on the cardiovascular system may be due to an excessive immune response—which is more likely in young, healthy people with strong immune systems.

Hypertension, Heart Disease History Associated With COVID-19 Hospitalization

Previous Smidt Heart Institute research published in Hypertension found that even in vaccinated people who received booster shots, hypertension more than doubles the risk of hospitalization related to Omicron infection.

By reviewing electronic medical records, Cedars-Sinai investigators identified 912 people who were fully vaccinated with an mRNA vaccine, received a booster shot, and were subsequently diagnosed with COVID-19 during the surge that occurred in Southern California from Dec. 1, 2021, through April 20, 2022. Of these individuals, 145 required hospitalization.

“We were surprised to learn that many people who were hospitalized with COVID-19 had hypertension and no other risk factors,” said Cheng, a senior author of the study. “This is concerning when you consider that almost half of American adults have high blood pressure.”

Investigators also found that chronic kidney disease and history of heart attack or heart failure greatly increase the risk of hospitalization after SARS-CoV-2 infection. Hypertension is common in people with these health conditions. Investigators conducted an analysis that excluded people diagnosed with these conditions and found that hypertension alone was associated with the greatest magnitude of risk: 2.6-fold.

These findings extend reports from early in the pandemic that also found associations between hypertension and severe COVID-19. Notably, the researchers found that conditions such as obesity and diabetes—which were identified as risk factors early in the pandemic—were not as strongly associated with hospitalization during the Omicron surge. The hypertension risk, however, persisted.

More research is needed to understand the biological processes that may cause more severe COVID-19 illness in people with hypertension and learn how to reduce this risk.

“Uncovering why hypertension is linked to COVID-19 could help us better understand how SARS-CoV-2 affects the body and provide clearer targets for prevention and treatment,” said Cheng.

Patients with hypertension who develop COVID-19 should be made aware of their heightened risk for hospitalization and are good candidates for antiviral therapy if infected with SARS-CoV-2.

A Dearth of Good COVID-19 Data

Our understanding of the trends in heart attack deaths in young people and other long-term effects of COVID-19 is challenged by a lack of good COVID-19 data.

Better tracking and reporting of COVID-19 cases could improve understanding of how the SARS-CoV-2 virus interacts with other health conditions. Determining if COVID-19 caused a hospitalization or death, or if a different health condition or illness is the culprit, is a “murky” process, Cheng said.

“It’s hard to parse things out except in the most obvious cases,” she said. “The healthcare system is still struggling to keep up. We do the best we can to code cases and deaths as appropriately as possible, but we are far from an ideal state of being able to talk about establishing consistency in how we code these things.”

 

To learn more about this study or other Smidt Heart Institute research, email heartinstitute@cshs.org.