Heart complications after SARS-CoV-2 infection, mRNA vaccine
Summary and introduction
Cardiac complications, particularly myocarditis and pericarditis, have been associated with infection with SARS-CoV-2 (the virus that causes COVID-19)[1–3] and COVID-19 mRNA vaccination.[2–5] Multisystem inflammatory syndrome (MIS) is a rare but serious complication of SARS-CoV-2 infection with frequent cardiac involvement. Using electronic health record (EHR) data from 40 US healthcare systems between January 1, 2021 and January 31, 2022, researchers calculated the incidence of cardiac outcomes (myocarditis; myocarditis or pericarditis; and myocarditis , pericarditis, or MIS) in people aged ≥5 years who have had SARS-CoV-2 infection, stratified by sex (male or female) and age group (5–11, 12–17, 18– 29 and ≥30 years old). Incidences of myocarditis and myocarditis or pericarditis were calculated after the first, unspecified second, or any (first, second, or unspecified) dose of COVID-19 mRNA (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) vaccines, stratified by sex and age group. Hazard ratios (RRs) were calculated to compare the risk of cardiac outcomes after SARS-CoV-2 infection to that after COVID-19 mRNA vaccination. The incidence of cardiac findings after COVID-19 mRNA vaccination was highest in males 12-17 years old after the second vaccine dose; however, among this demographic, the risk of heart problems was 1.8 to 5.6 times higher after SARS-CoV-2 infection than after the second dose of vaccine. The risk of cardiac outcomes was also significantly higher after SARS-CoV-2 infection than after a first, second, or unspecified dose of COVID-19 mRNA vaccination for all other groups by gender and by gender. age (RR 2.2–115.2). These findings support the continued use of COVID-19 mRNA vaccines among all eligible individuals aged ≥5 years.
This study used EHR data from 40 healthcare systems* participating in PCORnet, the national patient-centered clinical research network, January 1, 2021 through January 31, 2022. PCORnet is a national network of networks that facilitates healthcare data access and interoperability through the use of a common data model across healthcare systems. participant health (https://pcornet.org/data) . The PCORnet Common Data Model contains information extracted from EHRs and other healthcare data sources (e.g., health insurance claims), including demographics, diagnoses, prescriptions, procedures and laboratory test results, among other things. The study population included individuals with documented SARS-CoV-2 testing, viral illness diagnostic codes, or COVID-19 vaccination during the study period. Data was obtained through a single query run by participating healthcare systems to generate aggregated results.
Five cohorts were created using coded data from the EHR among individuals aged ≥ 5 years: 1) an infection cohort (individuals who received ≥ 1 positive molecular or antigen test result for SARS-CoV-2) ; 2) a first-dose cohort (people who received a first dose of a COVID-19 mRNA vaccine); 3) a second dose cohort (people who received a second dose of a COVID-19 mRNA vaccine); 4) an unspecified dose cohort (individuals who received an unspecified COVID-19 mRNA vaccine dose as a first or second dose); and 5) an all-dose cohort (individuals who received a dose of COVID-19 mRNA vaccine). The any-dose cohort is a combination of the other three vaccination cohorts; people who received 2 doses were included twice in this cohort, once for each dose.† Vaccine doses specifically coded as booster or supplemental doses were excluded. Individuals with a positive SARS-CoV-2 test result ≤30 days prior to receipt of a COVID-19 mRNA vaccine were excluded from the vaccine cohorts; individuals who had received a COVID-19 mRNA vaccine dose ≤ 30 days prior to a positive SARS-CoV-2 test result were excluded from the infection cohort. In the infection cohort, there were no further exclusions based on vaccination status. The following index dates were used for cohort entry: first positive SARS-CoV-2 test result for the infection cohort; first vaccination for the first dose cohort; second vaccination for the second dose cohort; single vaccination for the non-specific dose cohort; and first, second, and unspecified vaccination for the any-dose cohort. People could be represented twice in the any-dose cohort if they received a first and a second dose; they would have a different index date for each of the doses.
The incidence of three cardiac outcomes (myocarditis; myocarditis or pericarditis; and myocarditis, pericarditis or MIS) was defined using International Classification of Diseases, Tenth Revision, Clinical Modification (CIM-10-CM) diagnostic codes§ in risk windows of 7 or 21 days after the index date; persons with one of these diagnoses in the year prior to the index date were excluded. Outcome, including MIS, was only assessed for the infection cohort, as rare reports of MIS after COVID-19 mRNA vaccination typically showed evidence of prior SARS- CoV-2; a 42-day window of risk was also used for this outcome to account for a possible long latency between infection and GIS diagnosis¶. Since people with SIM who have cardiac involvement may only receive an ICD-10-CM code for SIM, rather than myocarditis or pericarditis, this combined result provided a comprehensive capture of complications. potential heart disease after infection. Nearly 80% of MIS cases have cardiac involvement. Cohorts were stratified by gender and age group.
Sex- and age-stratified incidences of cardiac outcomes (cases per 100,000 people) were calculated in risk windows of 7, 21, or 42 days. Unadjusted RRs and 95% CIs were calculated as the incidences of outcomes within the infection cohort divided by the incidences in the first, second, unspecified cohort and any dose cohort separately for each stratum of sex and age. RRs with CIs not including 1.0 were considered statistically significant; RRs were not compared across outcomes, risk windows, vaccine dose, or sex and age stratum. This activity has been reviewed by the CDC and was conducted in accordance with applicable federal law and CDC policy.**
The study population consisted of 15,215,178 people aged ≥ 5 years, including 814,524 in the infection cohort; 2,548,334 in the first dose cohort; 2,483,597 in the second dose cohort; 1,681,169 in the dose-unspecified cohort; and 6,713,100 in the any dose cohort (Table 1).†† Among the four COVID-19 vaccination cohorts, 77% to 79% of people were ≥ 30 years old; within the SARS-CoV-2 infection cohort, 63% were ≥ 30 years old.
In males aged 5-11 years, the incidence of myocarditis and myocarditis or pericarditis was 12.6-17.6 cases per 100,000 after infection, 0-4 after first dose of vaccine and 0 after the second dose; the incidences of myocarditis, pericarditis or MIS were 93.0 to 133.2 after infection (Table 2). Since there were no or few cases of myocarditis or pericarditis after vaccination, the RRs of several comparisons could not be calculated or were not statistically significant. RRs were significant when comparing myocarditis, pericarditis, or SIM within 42 days of infection (133.2 cases per 100,000) with myocarditis or pericarditis after the first (4.0 cases per 100,000 ; RR 33.3) or the second (4.7 cases per 100,000; RR 28.2 ) dose of vaccine.
In men aged 12 to 17, the incidence of myocarditis and myocarditis or pericarditis was 50.1 to 64.9 cases per 100,000 after infection, 2.2 to 3.3 after the first dose of vaccine and from 22.0 to 35.9 after the second dose; the incidences of myocarditis, pericarditis or MIS were 150.5 to 180.0 after infection. The RRs for cardiac outcomes comparing infected people with first-dose recipients were 4.9 to 69.0, and with second-dose recipients were 1.8 to 5.6; all RRs were statistically significant.
In men aged 18 to 29, the incidence of myocarditis and myocarditis or pericarditis was 55.3 to 100.6 cases per 100,000 after infection, 0.9 to 8.1 after the first dose of vaccine and 6.5 to 15.0 after the second dose; the incidences of myocarditis, pericarditis or MIS were 97.2 to 140.8 after infection. The RRs for cardiac outcomes comparing infected people with first dose recipients were 7.2 to 61.8, and with second dose recipients were 6.7 to 8.5; all RRs were statistically significant.
In men aged ≥30 years, the incidence of myocarditis and myocarditis or pericarditis was 57.2 to 114.0 cases per 100,000 after infection, 0.9 to 7.3 after the first dose of vaccine and 0.5 to 7.3 after the second dose; the incidences of myocarditis, pericarditis or MIS were 109.1 to 136.8 after infection. The RRs for cardiac outcomes in infected people compared to first-dose recipients were 10.7 to 67.2, and compared to second-dose recipients, were 10.8 to 115.2; all RRs were statistically significant.
In women aged 5 to 11 years, the incidence of myocarditis and myocarditis or pericarditis was 5.4 to 10.8 cases per 100,000 after infection, and the incidence of myocarditis, of pericarditis or SIM was 67.3 to 94.2 after infection (Table 3). No cases of myocarditis or pericarditis after vaccination have been identified. The incidence of cardiac outcomes did not vary by age in women aged ≥ 12 years. In this group, the incidences of myocarditis and myocarditis or pericarditis were 11.9 to 61.7 cases per 100,000 after infection, 0.5 to 6.2 after the first dose of vaccine, and 0. 5 to 5.4 after the second dose; the incidences of myocarditis, pericarditis or MIS were 27.1 to 93.3 after infection. In women aged ≥ 12 years, the RRs for cardiac outcomes comparing infected people to people who received the first dose were 7.4 to 42.6, and with people who received the second dose, 6.4 at 62.9; all RRs were statistically significant.