Four cases at Duke
In the second paper in JAMA Cardiology, a group led by Han W. Kim, MD, reported four patients with acute myocarditis occurring within days of mRNA COVID-19 vaccination (two Pfizer and two Moderna) in patients treated at Duke University Medical Center, Durham, N.C. The hospital courses of the four patients with myocarditis following COVID-19 vaccination were uneventful, and they were discharged within 2-4 days.
The authors said that, although a causal relationship cannot be established, none of the patients had a viral prodrome or had coincident testing that revealed an alternative explanation.
They stated that these four patients represent the majority of patients with acute myocarditis identified in the past 3 months at their institution, and this led to the highest total number of patients with acute myocarditis, compared with the same 3-month period for the past 5 years.
“Additionally, we identified only those patients with severe unremitting chest pain who sought medical attention. Those with mild or moderate chest pain might not seek medical attention, and it is possible that subclinical myocarditis may occur and could be detected by active surveillance, as has been described with smallpox vaccination,” they wrote.
Further case reports
In one of the papers in Circulation, a group led by Kathryn F. Larson, MD, from the Mayo Clinic in Rochester, Minn., described eight patients hospitalized with chest pain who were diagnosed with myocarditis within 2-4 days of receiving either the Pfizer or Moderna vaccine.
Two of the patients had previously been infected by SARS-CoV-2 without need for hospitalization. All individuals were otherwise healthy males between the ages of 21 and 56 years. All but one patient developed symptoms after their second dose, and the one patient who developed myocarditis after the first vaccine dose had previously been infected with SARS-CoV-2.
Systemic symptoms began within 24 hours after vaccine administration in five of eight patients, with chest pain presenting between 48 and 96 hours later. Troponin values were elevated in all individuals and appeared to peak the day after admission, whereas none had eosinophilia.
Cardiac MRI revealed findings consistent with myocarditis in all patients. All patients had resolution of their chest pain and were discharged from the hospital in stable condition.
“The patients presented here demonstrated typical signs, symptoms, and diagnostic features of acute myocarditis. The temporal association between receiving an mRNA-based COVID-19 vaccine and the development of myocarditis is notable,” the authors said.
They added that they would consider the use of corticosteroids in these patients but cautioned that this could reduce the specific immune response against SARS-COV-2 triggered by the vaccine. “Thus, the duration of corticosteroid administration should be limited to the resolution of the symptoms or ventricular arrhythmias or the recovery of the left ventricular ejection fraction.”
Pending publication of long-term outcome data after SARS-CoV-2 vaccine–related myocarditis, they suggest adherence to the current consensus recommendation to abstain from competitive sports for a period of 3-6 months with reevaluation prior to sports participation.
In another of the Circulation papers, a group led by Carolyn M. Rosner, MSN, presented a case series of seven patients hospitalized for acute myocarditis-like illness following COVID-19 vaccination, from two U.S. medical centers, in Falls Church, Va., and Dallas. All patients were males below the age of 40 years and of White or Hispanic race/ethnicity. Only one patient reported prior history of COVID-19 infection. Six patients received mRNA (Moderna or Pfizer) and one received the adenovirus (Johnson & Johnson) vaccine. All patients presented 3-7 days post vaccination with acute onset chest pain and biochemical evidence of myocardial injury.
Hospital length of stay was 3 days, and all patients’ symptoms resolved by hospital discharge.
And finally, the third paper in Circulation reported a detailed description of one patient – a 52-year-old, previously healthy male who presented with acute myocarditis 3 days after the administration of the second dose of Moderna’s COVID-19 vaccine. The symptoms resolved, and there was a gradual improvement in cMRI findings. Ischemic injury and other potential causes of acute myocardial injury were excluded, as were other potential infectious causes of myocarditis, and there was no evidence of systemic autoimmune disease.
“Clinicians should be aware that myocarditis may be present in patients exhibiting cardiac signs and symptoms 2-4 days after COVID-19 vaccination,” the authors said.
They added that additional surveillance of such adverse events post–COVID-19 vaccination will help identify subgroups at higher risk for this vaccine-related effect, and whether additional precautions are necessary.