Long-term follow-up of cardiac magnetic resonance imaging in myocarditis following messenger ribonucleic acid COVID-19 vaccination: a case report

Abstract

Background: Presently, the association between myocarditis and messenger ribonucleic acid (mRNA) COVID-19 vaccination is well established. From the most current data, cases of myocarditis following COVID-19 vaccination seem to be mild with fast clinical recovery. Nevertheless, the complete resolution of the inflammatory process is still unclear.

Case summary: We report the case of a 13-year-old boy who developed chest pain following the second dose of the Pfizer-BioNTech COVID-19 vaccine with long-term follow-up of cardiac magnetic resonance (CMR) imaging. An electrocardiogram (ECG) revealed progressively ST-segment elevation on the 2nd day of admission with a rapid improvement within 3 hours where only mild ST-segment elevation remained. The peak level of high-sensitivity cardiac troponin T was 1546 ng/L with rapid reduction. Echocardiogram revealed depressed left ventricular septal wall motion. CMR mapping techniques showed myocardial oedema with an increase in native T1 and extracellular volume (ECV). On the other hand, T1-weighted and T2-weighted images and late gadolinium enhancement (LGE) did not detect inflammation. The patient's symptoms were relieved by oral ibuprofen. After 2 weeks, ECG and echocardiogram were unremarkable. However, the inflammation process was still present based on the CMR by mapping technique. During the 6-month follow-up, CMR returned to normal.

Discussion: In our case, the subtle myocardial inflammation was diagnosed by mapping technique with only a T1-based marker according to the updated Lake Louise Criteria and the inflammation of the myocardium returned to normal within 6 months after the onset of the disease. Further follow-up and larger studies are needed to determine the complete resolution of the disease.

Keywords: Cardiac magnetic resonance; Case report; Long-term follow-up; Myocarditis; mRNA vaccine.

Figure 1

Electrocardiogram (ECG). (A) ECG on day 1 shows diffuse ST elevation in lead I, II, aVL, aVF, and V₂–V₆ with ST depression in lead V₁. (B) ECG on day 2 shows progressive ST elevation. (C) ECG on day 2 after 3 h shows significant improvement in ST-segment elevation. (D) ECG after 1-week follow-up shows ST elevation in lead V₂–V₅, the biphasic T waves in lead I, II, III, aVL, and V₄–V₆ with incomplete right bundle branch block.

Figure 2

Strain imaging echocardiography: regional longitudinal strain shows mildly depressed left ventricular function at anteroseptal and inferoseptal area.

Figure 3

Serial cardiac magnetic resonance (CMR) imaging performed on admission day (1), 2 weeks (2), and 6 months (3). The figure shows steady-state free precession imaging (SSFP CINE), T1-weighted imaging (T1W), T2-weighted imaging (T2W), T2-weighted short-tau inversion recovery imaging (T2W STIR), late gadolinium enhancement imaging (LGE), native T1 mapping (nT1 mapping), enhanced T1 mapping (eT1 mapping), and T2 mapping.

Figure 4

(A) Native T1 mapping and postcontrast images showing a region of interest (ROI) draw in the six basal segments with increased T1 native in all segments (1031 ± 23.7 ms) and postcontrast T1 mapping (469 ± 20.3 ms), and (B) T2 mapping image with value (54.1 ± 2.96 ms). Data are reported as mean ± SD (range). Cutoff value: T1 native > 1000 ms, T2 native > 55.9 ms. The normal values at our centre: native T1 mapping = 998 ± 23.9 ms, enhanced T1 mapping = 420 ± 9 ms, T2 mapping = 54.6 ± 8.64 ms. ms, milliseconds. Cardiac magnetic resonance (CMR) acquisition protocol included balanced steady-state free precession cine-MR (SSFP cine MR) images. Oedema CMR was performed by black–blood T2-weighted short tau inversion recovery (STIR) and T2 mapping. A dose of 0.2 mmol/kg Gadobutrol (Gd-DO3A-butrol, Gadovist; Bayer Healthcare, Leverkusen, Germany) was injected with a rate of 2.5 mL/s.