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Vaccination against COVID-19 is associated with fewer major adverse cardiovascular events (MACE) among people who were previously infected with SARS-CoV-2, a new report suggests.
Patients who were fully vaccinated had a 41% lower risk of experiencing a cardiac event versus those who were not vaccinated. Partially vaccinated people had a 24% lower risk.
“To our surprise, even partial vaccination was associated with lower risk of adverse cardiovascular events,” said first author Joy Jiang, an MD/PhD candidate at the Icahn School of Medicine at Mount Sinai in New York City.
“Given the magnitude of SARS-CoV-2 infection worldwide, we hope our findings could help improve vaccination rates, especially in individuals with coexisting conditions,” she said.
The study was published online in the Journal of the American College of Cardiology on February 20, and will be presented at the upcoming American College of Cardiology (ACC) Scientific Session/World Congress of Cardiology (WCC) 2023.
SARS-CoV-2 infection increases the risk for MACE and long-term cardiovascular complications after recovery, the study authors write. However, questions have remained about COVID-19 vaccination and the association with cardiovascular outcomes after a prior infection.
Jiang and colleagues analyzed data from the National COVID Cohort Collaborative (N3C), including patients ages 18-90 who were initially infected with SARS-CoV-2 between March 1, 2020, and February 1, 2022. Starting from the first day after initial infection, the follow-up time was 180 days.
The research team included mRNA vaccines by Pfizer-BioNTech and Moderna, as well as vector vaccines by Johnson and Johnson. Patients were classified as fully vaccinated if they received two or more mRNA doses or one Johnson and Johnson dose 14 or more days before infection. Partial vaccination was considered as one mRNA dose or a second mRNA dose or single Johnson and Johnson dose within 14 days of infection.
Among more than 1.9 million patients, the average age was 45, and 55.9% were women. About 81.3% of patients were White, 15.5% were Black, 2.4% were Asian, 0.6% were “other,” and 0.2% were Native Hawaiian or Pacific Islander.
Overall, 195,136 patients (10.1%) were fully vaccinated, and 22,707 patients (1.2%) were partially vaccinated. The remaining 1.7 million people (88.7%) weren’t vaccinated.
Major adverse cardiovascular events were observed among 13,948 patients (0.7%), including 12,733 cases among nonvaccinated patients (0.7%), 160 among partially vaccinated patients (0.7%), and 1055 in fully vaccinated patients (0.5%).
The median time to MACE after infection was 17 days, and the median time from the last vaccination to MACE was 212 days. In total, 3175 patients died after MACE.
In general, patients with MACE had significant differences in comorbidities from those who didn’t experience an event. For instance, about 29.1% of patients with MACE had a previous MACE compared with 0.9% who didn’t experience an event.
In addition, among patients with MACE versus those without, 33.9% had type 2 diabetes (versus 7.5%), 50.7% had hyperlipidemia (versus 14.4%), 40.6% had ischemic heart disease (versus 3.9%), 4% had liver disease (versus 0.8%), and 29.4% had obesity (versus 16.4%).
The risk for MACE significantly increased after infection for men, those aged 66 or older, and those with comorbidities, especially previous MACE.
However, both full vaccination and partial vaccination were associated with a reduced risk for MACE. Full vaccination was associated with a 41% lower risk for MACE in the 6 months after infection compared with no vaccination (adjusted hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.55 – 0.63), and partial vaccination was associated with a 24% lower risk for MACE compared with no vaccination (adjusted HR, 0.76; 95% CI, 0.65 – 0.89).
“We sought to clarify the impact of previous vaccination on cardiovascular events among people who develop COVID-19 and found that, particularly among those with comorbidities such as previous MACE, type 2 diabetes, high cholesterol, liver disease, and obesity, there is an association with a lower risk of complications,” said senior author Girish Nadkarni, MD, a professor of medicine at the Icahn School of Medicine at Mount Sinai.
“While we cannot attribute causality, this shows supportive evidence that vaccination may have beneficial effects on a variety of post-COVID-19 complications,” he said.
Investigating Next Steps
Additional studies are needed to understand the mechanisms involved, the study authors write, as well as how new variants and reinfections affect the risk for MACE.
“Evidence keeps piling up that SARS-CoV-2 infection increases risk of heart problems, and there is evidence that vaccination reduces that risk,” said Ziyad Al-Aly, MD, chief of research and development at the Veterans Affairs St. Louis Health Care System and clinical epidemiologist at Washington University in St. Louis, Missouri.
Al-Aly, who wasn’t involved with this study, has researched cardiovascular complications after infection, including Long COVID. He and colleagues have found that vaccination provides some protection.
“There is so much vaccine hesitancy and misinformation out there — this letter further adds to the evidence base providing data that vaccines actually reduce risk of major heart problems,” he said. “They show a nice, graded degree of protection — you get some protection from partial vaccination but most optimal protective effect from full vaccination.”
J Am Coll Cardiol. Published online February 20, 2023. Full text
American College of Cardiology (ACC) Scientific Session/World Congress of Cardiology (WCC) 2023. Presentation #1458-185/185. To be presented March 5, 2023.
The study was supported by the National COVID Cohort Collaborative (N3C) and IDeA CTR Collaboration. The authors disclosed research funding, consultancy agreements, and honoraria from various organizations and companies not involved with this paper. Al-Aly declared no relevant financial relationships.
Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape, MDedge, and WebMD.
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