This study shares the experience of a large specialized cardiac center in assessing and managing patients who developed myocarditis and/or pericarditis following the administration of COVID-19 vaccination. As shown in previous studies, myocarditis was seen more frequent than pericarditis [9, 10]. As expected, the majority of patients in the current study were adolescent or young adult (85% below 40 years), males (70%), who develop symptoms within few days (median 3 days) from receiving second/booster doses of COVID-19 vaccine (79%). The findings were very close to those reported by large systematic reviews that described more than 20,000 myocarditis and pericarditis events reported to regulatory authorities in USA, UK, and Europe [20–22]. The reviews confirmed higher risk in males (60–82%), younger age (60% were less than 40% in USA), and with second dose (47–82%) [20–22]. Symptoms in previous studies started on average after 2–4 days after vaccination [22, 23]. These classic epidemiologic characteristics of VAMPS may be explained by the underlying pathophysiologic mechanisms; the male predominance may be related to the possible protective role of female sex hormones while the higher risk after the second dose may be related to autoimmune reaction that requires developing autoantibodies after the first dose [10, 11].
Cardiac MRI is widely accepted as the most important non-invasive confirmatory method of VAMPS, which can be used also in follow-up and to guide clinical decisions [19]. Similar to previous studies [19, 24, 25], cardiac MRI was abnormal in 90% of the patients in the current study. The most frequent MRI findings were largely preserved LV function (80%), LEG of subepicardial and/or mid wall pattern (65%), and pericardium effusion (55%). A large systematic review including 468 patients with vaccine-associated myocarditis showed that 91% of the patients had LEG of subepicardial and/or mid wall pattern and 96% of the patients had preserved LV function [24]. Another smaller study showed that all patients with vaccine-associated pericarditis had pericardial effusion with thickening and/or LGE of pericardial layers [19].
The most frequent laboratory tests examined in the current study were WBCs, Troponin, BNP, CRP, and ESR. They were examined in 70–95% of the patients. The most frequently elevated laboratory test was CRP (66%), followed by BNP (44%) troponin (33%), and ESR (29%). These results were generally lower than reported in a systematic review of similar case studies and case series where troponin, CRP, BNP, and ESR were elevated in 99%, 90%, 78%, and 60% of the patients with VAMPS [26]. It should be noted that with the exception of troponin which was examined on most of the patients, other laboratory tests reported in the systematic review were examined only sporadically in the patients with VAMPS [23, 26].
The majority of patients in the current study recovered using anti-inflammatory medications mainly colchicine (72%), aspirin (39%), and ibuprofen (33%). Unlike cardiac injury due to COVID-19 infection, the prognosis of VAMPS is usually benign [23, 27]. For example, in a retrospective analysis of 238 patients with vaccine-associated myocarditis in the USA, death was observed in five (1.7%) patients including three (1.3%) patients with biopsy/autopsy-confirmed myocarditis [23]. Even lower mortality (0.9%) was observed in the European union database for adverse reactions of drugs (EudraVigilance database) [28]. Although none of the patients in the current study died, VAMPS can result in serious complications such as constrictive pericarditis cardiac arrest, dilated cardiomyopathy and drop in left ventricular function.
In conclusion, we are reporting a cohort of 20 patients with VAMPS. The patients were typically adolescent or young adult, males, who developed symptoms within few days from receiving second/booster dose of COVID-19 vaccine. Cardiac MRI and laboratory testing can help in confirming the diagnosis. Although none of the patients died, 30% developed serious complications. Cardiologists should put the possibility of VAMPS in the differential diagnosis of patients who recently received COVID-19 vaccinations.