Cardiac Risks Higher With COVID-19 Infection Than mRNA Vaccination
Even though they are very rare, cardiac risks such as myocarditis and pericarditis remain a concern for adolescent males who get COVID-19 shots, especially after the second vaccine dose. New research documents, however, that the risk of those and other cardiac outcomes after infection with SARS-CoV-2 is considerably higher than that with mRNA vaccines. Here is more information pharmacists can share with those concerned about getting vaccinated.
BOSTON – For adolescent males, 12-17, the incidence of cardiac outcomes after mRNA COVID-19 vaccination was highest after the second vaccine dose, but the risk remained much higher -- 1.8–5.6 times – with SARS-CoV-2 infection than vaccination.
That’s according to an article in the national Centers for Disease Control and Prevention’s Morbidity & Mortality Weekly Report. Researchers led by Harvard Medical School and the CDC COVID-19 Emergency Response Team add that the risk for cardiac outcomes “was likewise significantly higher after SARS-CoV-2 infection than after first, second, or unspecified dose of mRNA COVID-19 vaccination for all other groups by sex and age (RR 2.2–115.2). These findings support continued use of mRNA COVID-19 vaccines among all eligible persons aged ≥5 years.”
Background information in the article notes that cardiac complications, especially myocarditis and pericarditis, have been associated with SARS-CoV-2, the virus that causes COVID-19 infection, as well as RNA COVID-19 vaccination. In addition, the authors note that multisystem inflammatory syndrome (MIS), a rare but serious complication of SARS-CoV-2 infection, frequently involves cardiac symptoms.
The study team used electronic health record (EHR) data from 40 U.S. health care systems during Jan. 1, 2021–Jan.31, 2022 to estimate incidences of cardiac outcomes -- myocarditis; myocarditis or pericarditis; and myocarditis, pericarditis, or MIS – among anyone over age 5 who had SARS-CoV-2 infection. Results were stratified by sex (male or female) and age group (5–11, 12–17, 18–29, and ≥30 years.
Researchers also quantified cases of myocarditis and myocarditis or pericarditis after the first, second, unspecified, or any (first, second, or unspecified) dose of mRNA COVID-19 (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) vaccines, stratified by sex and age group.
Essentially, five cohorts were created:
- an infection cohort (patients who received 1 or more positive SARS-CoV-2 molecular or antigen test results);
- a first dose cohort including those who received the first dose of an mRNA COVID-19 vaccine
- a second dose cohort (those who received a second dose of an mRNA COVID-19 vaccine);
- an unspecified dose cohort (those who received an mRNA COVID-19 vaccine dose not specified as a first or second dose); and
- an any-dose cohort (those who received any mRNA COVID-19 vaccine dose). The any-dose cohort is a combination of the other three vaccination cohorts; persons who received 2 doses were included twice in this cohort, once for each dose, although vaccine doses specifically coded as booster or extra doses were excluded.
Researchers looked at cardiac outcomes within a 7-day or 21-day risk window. The outcome including MIS was assessed only for the infection cohort, and a 42-day risk window was used for that outcome to allow for a possible long latency between infection and diagnosis of MIS.
Overall, the study population included about 15 million people, including 814,524 who had been infected, about 2.5 million each in the first and second dose cohorts, 1.7 million in the unspecified dose cohort and 6.7 million in the any-dose cohort. Among those who were vaccinated, 77%–79% of persons were 30 or older; the percentage was 63% among those who had been infected.
Results indicate that, among males aged 12–17 years, the incidences of myocarditis and myocarditis or pericarditis were 50.1–64.9 cases per 100,000 after infection, 2.2–3.3 after the first vaccine dose, and 22.0–35.9 after the second dose compared to 150.5–180.0 after infection. “RRs for cardiac outcomes comparing infected persons with first dose recipients were 4.9–69.0, and with second dose recipients, were 1.8–5.6; all RRs were statistically significant,” the authors note.
Among older males, aged 18–29 years, the study determined that incidences of myocarditis and myocarditis or pericarditis were 55.3–100.6 cases per 100,000 after infection, 0.9–8.1 after the first vaccine dose, and 6.5–15.0 after the second dose. Incidences of myocarditis, pericarditis, or MIS were 97.2–140.8 after infection. That means that RRs for cardiac outcomes comparing infected persons with first dose recipients were 7.2–61.8, and 6.7–8.5 for second dose recipients, which researchers consider statistically significant.
For males over 30, incidences of myocarditis and myocarditis or pericarditis were 57.2–114.0 cases per 100,000 after infection, 0.9–7.3 after the first vaccine dose, and 0.5–7.3 after the second dose vs. 109.1–136.8 after infection. Among females aged 5–11 years, incidences of myocarditis and myocarditis or pericarditis were 5.4–10.8 cases per 100,000 after infection, and incidences of myocarditis, pericarditis, or MIS were 67.3–94.2 after infection, according to the report, which adds that no cases after vaccination were identified.
Among females 12 and older, RRs for cardiac outcomes comparing infected persons with first dose recipients were 7.4–42.6, and with second dose recipients, were 6.4–62.9, which also were statistically significant, the authors write.