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A new registry study suggests that cases of myocardial inflammation following administration of the Pfizer-BioNTech mRNA COVID-19 vaccine have significantly lower mortality compared with myocarditis associated with viral infection.
The researchers examined Hong Kong Territory National Health Registry data to compare 6-month outcomes in patients who developed myocarditis after administration of the Pfizer-Biontech COVID-19 vaccine (BNT162b2) to non-COVID-19 compared with a historical control group of patients. viral myocarditis A case that occurred before the pandemic.
They identified 104 patients with myocarditis after COVID-19 vaccination and 762 patients with myocarditis associated with viral infections other than COVID-19.
Results showed that 1 (1%) of 104 patients with post-vaccination myocarditis died, compared with 84 (11%) of 762 patients with viral infection-associated myocarditis. rice field.
An adjusted analysis showed that the post-vaccination myocarditis group had a 92% lower risk of death compared with the historical control group (adjusted HR, 0.08; 95% CI, 0.01-0.57).
1 case (1%) dilated cardiomyopathy and 2 cases (1.9%) heart failure 28 (3.7%) and 93 (12.2%) in the post-vaccination group compared with 28 (3.7%) and 93 (12.2%) in the viral infection-associated myocarditis group, respectively.
No significant differences were found in other prognostic outcomes.
The study appears in the December 13th issue Journal of the American College of CardiologyWhen published online today.
“The incidence of postmyocarditis, heart failure and dilated cardiomyopathy after mRNA vaccination is very low (less than 1 per 10,000 person-days), with an incidence of 7, 8, 2 per 10,000 person-days and were contrasting among patients with viral infection-associated myocarditis, respectively,” said the authors, led by Dr. Francisco Tsz Tsun Lai of the University of Hong Kong.
They note that about 4 million people in Hong Kong have been vaccinated with Pfizer Biontech’s COVID-19 vaccine. The 104 cases of myocardial inflammation identified in the study as possibly related to the vaccine represent a rate of 2.6 cases per 100,000 people, which is comparable to previous estimates in other populations, they note. I’m here.
The authors also report that the findings of this study are otherwise consistent with the existing literature. First, the demographic characteristics of the post-mRNA vaccination cohort of myocarditis patients were more male and generally younger. Second, the prognosis of myocarditis patients after mRNA vaccination was usually mild, with few deaths or other poor outcomes recorded.
“Nevertheless, this study is, to our knowledge, the first to compare the prognostic outcomes of mRNA vaccine-associated myocarditis and viral infection-associated myocarditis,” they say.
“Importantly, patients with myocarditis after mRNA vaccination had a significantly and significantly lower mortality compared with those with viral infection-associated myocarditis.”
They noted that this difference was already adjusted for different clinical histories, medication use, and demographic information, thus distinguishing this finding from those acquired by other methods such as viral infection. , may point to a potentially different etiology of myocarditis conditions associated with mRNA vaccines.
“Given immunology, it may be prudent to predict a milder prognosis because of the usual brief exposure to stimuli that provoke an immune response (vaccine versus virus),” they added.
They also noted that underlying health status, particularly cardiovascular health, in patients with myocarditis following mRNA vaccination was better across age groups than in patients with viral infection-associated myocarditis. increase.
“This finding potentially suggests that the incidence of myocarditis associated with viral infection is generally higher in people with underlying medical conditions,” they commented. “Therefore, it also reflects the iatrogenicity of cases of myocardial inflammation associated with mRNA vaccines, which can occur in otherwise healthy individuals. Low incidence of mortality, heart failure, and cardiomyopathy. may be partly explained by this observation.”
“Reliable First Look”
and Accompanying editorialPeter P. Liu, MD and Tahir S. Kafil, MD, of the University of Ottawa, Ottawa, Canada, point out some limitations of the current study.
These included the lack of standardized case-definition criteria for vaccine-associated myocarditis, and investigators were unable to confirm the diagnosis of myocarditis with clinical study data such as: cardiac MRIwe were also unable to confirm the exclusion of other potential causes of myocarditis.
They also noted that the comparison group was “not ideal” because viral myocarditis is a highly heterogeneous group of conditions affected by local seasonal viral patterns and underlying population comorbidities. points out.
They suggested that COVID-19-induced myocarditis might be a better comparator, and the US National Patient-Centered Clinical Research Network (PCORnet) records examined More than 15 million patients from 40 healthcare systems were studied to determine their risk for adverse cardiac events such as myocarditis.pericarditis Young men are still 1.8- to 5.6-fold higher after COVID-19 infection than after COVID-19 vaccination.
Noting that the mechanisms behind this vaccine-associated myocarditis are unknown, the editors noted the anticipated need for routine COVID-19 booster vaccinations and the potential for various other medical indications. Vaccine myocarditis continues to be an ongoing challenge given the advances in mRNA technology for pneumonia. in the near future.
They need to work together to understand the long-term outcome of these patients, identify specific individual risk factors leading to the development of myocarditis, and identify mitigation strategies for those affected. I point out that there is.
“Participating in a global collaborative study is critical to our overall success. This current study provides a reassuring first look at outcome data six months after BNT162b2 vaccination. But it’s not time to roll up your sleeves yet,” they conclude.
This study was funded by a research grant from the Department of Food Health, Government of the Hong Kong Special Administrative Region. Lai reported research funding from the Laboratory of Data Discovery for Health, her RGC Postdoctoral Fellowship under the Hong Kong Research Grants Council, funded by her AIR@InnoHK managed by the Innovation and Technology Commission. I’m here. and the Food Sanitation Department of the Government of the Hong Kong Special Administrative Region.
J Am Call CardiolPublished online December 5, 2002. Overview, editorial
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