Cardiac adverse reactions of COVID-19 vaccination: cardiac MRI findings.

BACKGROUND: The rapid development of COVID-19 vaccines in the wake of the COVID-19 pandemic has led to an equally expediently deployed vaccination campaign with more than 12 billion vaccinations administered worldwide. Reports of vaccine-associated adverse reactions (VAARs) have ranged from headaches and pain at the injection site to potentially life-threatening events such as cerebral venous sinus thrombosis. The heart has also not been spared of VAARs, as vaccine-associated myocardial infarction and more commonly, albeit still rare, myocarditis and perimyocarditis have been reported in predominantly young male recipients. METHODOLOGICAL INNOVATIONS: Cardiac magnetic resonance imaging findings of vaccine-associated myocarditis such as prolonged T1 and T2 relaxation times, increased T2 signal intensity ratio, and subepicardial late gadolinium enhancement have been demonstrated to be similar to those in virus-induced myocarditis, enabling the use of the modified 2018 Lake Louise Criteria for diagnostic purposes to confirm vaccination-associated myocardial inflammation. Other reported cardiac findings such as cardiomyopathies and arrhythmias were confined to case reports. The incidence of myocardial infarction was not noted to be higher than in the overall population. CONCLUSION: The overall preliminary prognosis of vaccine- associated myocarditis seems to be good as suggested by initial reports, but long-term follow-up is needed to sufficiently assess possible sequelae and consequences.

Cardiac MRI in Suspected Acute Myocarditis After COVID-19 mRNA Vaccination.

PURPOSE: To evaluate cardiac MRI characteristics in patients with suspected hypersensitivity myocarditis following mRNA COVID-19 vaccination. MATERIALS AND METHODS: Patients clinically suspected of acute myocarditis after COVID-19 vaccination were retrospectively analyzed and compared against a healthy control group. Cardiac MRI protocol included parameters such as T1 and T2 relaxation times, extracellular volume (ECV), T2 signal intensity ratio, and late gadolinium enhancement (LGE). Lymph node size was assessed in the patient group on the injection side. Student t-test, analyses of variance (ANOVA) with Tukey post-hoc test, and χ2 test were used for statistical analysis. RESULTS: 20 patients with clinically suspected post-vaccine myocarditis (28 ±â€Š12 years; 12 men) and 40 controls (31 ±â€Š11 years; 25 men) were evaluated. According to the 2018 Lake Louise criteria (LLC), patients with clinically suspected myocarditis were further subdivided into an LLC-positive group (n = 9) and an LLC-negative group (n = 11). The mean time of symptom onset after vaccination was 1.1 ±â€Š1.2 days (LLC-positive) and 6.5 ±â€Š9.2 days (LLC-negative). Group differences in inflammatory variables between myocarditis patients and control subjects were more pronounced in the LLC-positive group (e. g., T1 relaxation time: 1041 ±â€Š61 ms [LLC positive] vs. 1008 ±â€Š79 ms [LLC-negative] vs. 970 ±â€Š25 ms [control]; p <.001; or T2 signal intensity ratio 2.0 ±â€Š0.3 vs. 1.6 ±â€Š0.3 [LLC-negative] and vs. 1.6 ±â€Š0.3 [control], p = .012). LLC-positive patients were significantly faster in receiving an MRI after initial symptom onset (8.8 ±â€Š6.1 days vs. 52.7 ±â€Š33.4 days; p = .001) and had higher troponin T levels (3938 ±â€Š5850 ng/l vs. 9 ±â€Š11 ng/l; p <.001). LGE lesions were predominantly located at the subepicardium of the lateral wall. Axillary lymphadenopathy was more frequent in the LLC-positive group compared to the LLC-negative group (8/9 [89 %] vs. 0/11 [0 %], p < 0.001). CONCLUSION: Vaccine-induced myocarditis should be considered in patients with acute symptom onset after mRNA vaccination, especially if elevated serum troponin T is observed. Imaging findings of vaccine-induced myocarditis are similar to virus-induced myocarditis, allowing for the use of the Lake Louise Criteria for diagnostic purposes. KEY POINTS: · Vaccine-induced hypersensitivity myocarditis can be confirmed with cardiac MRI. · Especially patients with sudden onset of symptoms and elevated serum troponin T had positive cardiac MRI findings. · Cardiac MRI characteristics of vaccine-induced myocarditis are similar to those in virus-induced myocarditis. CITATION FORMAT: · Kravchenko D, Isaak A, Mesropyan N et al. Cardiac MRI in Suspected Acute Myocarditis After COVID-19 mRNA Vaccination. Fortschr Röntgenstr 2022; 194: 1003 - 1011.