Cardiac Magnetic Resonance Findings of Coronavirus Disease 2019 (COVID-19) Vaccine-Associated Myopericarditis at Intermediate Follow-Up: A Comparison with Classic Myocarditis

Abstract

Objective: To report intermediate cardiac magnetic resonance (CMR) findings of coronavirus disease 2019 (COVID-19) vaccine-associated myopericarditis (C-VAM) and compare with classic myocarditis.

Study design: Retrospective cohort study including children diagnosed with C-VAM from May 2021 through December 2021 with early and intermediate CMR. Patients with classic myocarditis from January 2015 through December 2021 and intermediate CMR were included for comparison.

Results: There were 8 patients with C-VAM and 20 with classic myocarditis. Among those with C-VAM, CMR performed at a median 3 days (IQR 3, 7) revealed 2 of 8 patients with left ventricular ejection fraction <55%, 7 of 7 patients receiving contrast with late gadolinium enhancement (LGE), and 5 of 8 patients with elevated native T1 values. Borderline T2 values suggestive of myocardial edema were present in 6 of 8 patients. Follow-up CMRs performed at a median 107 days (IQR 97, 177) showed normal ventricular systolic function, T1, and T2 values; 3 of 7 patients had LGE. At intermediate follow-up, patients with C-VAM had fewer myocardial segments with LGE than patients with classic myocarditis (4/119 vs 42/340, P = .004). Patients with C-VAM also had a lower frequency of LGE (42.9 vs 75.0%) and lower percentage of left ventricular ejection fraction <55% compared with classic myocarditis (0.0 vs 30.0%), although these differences were not statistically significant. Five patients with classic myocarditis did not receive an early CMR, leading to some selection bias in study design.

Conclusions: Patients with C-VAM had no evidence of active inflammation or ventricular dysfunction on intermediate CMR, although a minority had persistent LGE. Intermediate findings in C-VAM revealed less LGE burden compared with classic myocarditis.

Keywords: BNT162 vaccine; C-VAM; CMR; COVID vaccine; SARS-CoV-2; mRNA vaccine.

Figure 1

Flow chart of C-VAM and classic myocarditis patients during the study period. Bolded boxes indicate patients included in the cohorts. LLC – modified Lake Louise Criteria. LGE – late gadolinium enhancement.

Figure 2

LGE distribution and burden among myocarditis groups. Frequency of left ventricular wall segments with LGE among patients with C-VAM and classic myocarditis. Segments are recorded in accordance with the 17-segment AHA heart model. The classic myocarditis 2-12 month graphic only includes the 15 classic myocarditis patients who had early CMR.

Figure 3

CMR Images from C-VAM Patient. Top row: Baseline CMR performed 1 day after diagnosis of C-VAM with short axis images including (A) early post-contrast T1-weighted spoiled gradient compressed SENSE cine still frame showing regional signal hyperintensity (B) late gadolinium enhancement and (C) corresponding regional post-contrast shortening of T1 relaxation times in the basilar inferolateral segment as depicted by the arrow. Bottom row: Follow-up CMR performed at 89 days after diagnosis with short axis images including (D) normal native T1 mapping relaxation times (E) normal T2 mapping relaxation times (F) persistent late gadolinium enhancement and (G) post-contrast shortening of T1 relaxation times in the basilar inferolateral segment as depicted by the arrow.

Figure 4

LGE distribution and burden among myocarditis groups with inclusion of the 15 classic myocarditis patients with early CMR and the full complement of 20 patients with intermediate CMR. Frequency of left ventricular wall segments with LGE among patients with C-VAM and classic myocarditis. Segments are recorded in accordance with the 17-segment AHA heart model. The early classic myocarditis graphic includes 15/20 study patients with early CMR, and the 2-12 month classic myocarditis graphic includes the full complement of 20 patients who had intermediate CMR available.