Abstract：
OBJECTIVE: In 2021, the US Centers for Disease Control and Prevention reported increased cases of myocarditis and pericarditis in the United States after mRNA COVID-19 vaccines. Our study aims to estimate the incidence of myocarditis in Apulia (Southern Italy) and the cause-effect relationship between COVID-19 mRNA vaccines and the risk of myocarditis.
METHODS: The Apulian regional archive of hospital discharge forms was used to define the cases of myocarditis in Apulia, considering data from 2017 to 2022. The overall vaccination status of patients was assessed via data collected from the Regional Immunization Database. The history of SARS-CoV-2 infection was extracted from the Italian Institute of Health platform.
RESULTS: Since 2017, 5687 cases of myocarditis have been recorded in Apulian subjects; the overall incidence described a decreasing trend, with a slight increase in 0-40 years-old subjects. From 2021 to 2022, 2,930,276 doses of COVID-19 mRNA vaccines were administered; a diagnosis of myocarditis after the second dose of the mRNA vaccine was reported for 894 (0.03%) of Apulian inhabitants, with an incidence rate of 17.9 × 1,000,000 persons-month. The multivariate analysis, adjusted for age, sex, underlying medical conditions, and diagnosis of COVID-19, showed that mRNA vaccination is a protective factor for myocarditis even in younger subjects (aOR = 0.4; 95% CI = 0.3-0.5).
CONCLUSIONS: A temporal association between an exposure and an outcome is not equivalent to a causal association. Our study underlines how an approach that considers the other potential causes of myocarditis (primarily COVID-19) and a causality assessment must be prioritized in the study of the topic.
METHODS: The Apulian regional archive of hospital discharge forms was used to define the cases of myocarditis in Apulia, considering data from 2017 to 2022. The overall vaccination status of patients was assessed via data collected from the Regional Immunization Database. The history of SARS-CoV-2 infection was extracted from the Italian Institute of Health platform.
RESULTS: Since 2017, 5687 cases of myocarditis have been recorded in Apulian subjects; the overall incidence described a decreasing trend, with a slight increase in 0-40 years-old subjects. From 2021 to 2022, 2,930,276 doses of COVID-19 mRNA vaccines were administered; a diagnosis of myocarditis after the second dose of the mRNA vaccine was reported for 894 (0.03%) of Apulian inhabitants, with an incidence rate of 17.9 × 1,000,000 persons-month. The multivariate analysis, adjusted for age, sex, underlying medical conditions, and diagnosis of COVID-19, showed that mRNA vaccination is a protective factor for myocarditis even in younger subjects (aOR = 0.4; 95% CI = 0.3-0.5).
CONCLUSIONS: A temporal association between an exposure and an outcome is not equivalent to a causal association. Our study underlines how an approach that considers the other potential causes of myocarditis (primarily COVID-19) and a causality assessment must be prioritized in the study of the topic.
摘要：
背景：2021年，美国疾病控制和预防中心报告了在美国使用mRNACOVID-19疫苗后，心肌炎和心包炎的病例增加。我们的研究旨在评估阿普里亚（意大利南部）心肌炎的发病率以及COVID-19mRNA疫苗与心肌炎风险之间的因果关系。
方法：使用Apulian地区出院表格档案来定义Apulia的心肌炎病例，考虑2017年至2022年的数据。通过从区域免疫数据库收集的数据评估患者的总体疫苗接种状态。SARS-CoV-2感染的病史是从意大利卫生研究所平台提取的。
结果：自2017年以来，Apulian受试者中记录了5,687例心肌炎；总体发病率呈下降趋势，在0-40岁的受试者中略有增加。从2021年到2022年，施用了2,930,276剂COVID-19mRNA疫苗；据报道，894名（0.03％）的普利亚居民在第二剂mRNA疫苗后诊断为心肌炎，发病率为17.9×1,000,000人-月。多变量分析，根据年龄调整，性别,潜在的医疗状况，和COVID-19的诊断表明，即使在年轻受试者中，mRNA疫苗也是心肌炎的保护因素(aOR=0.4；95CI=0.3-0.5)。
结论：暴露与结果之间的时间关联并不等同于因果关系。我们的研究强调了如何在该主题的研究中优先考虑考虑心肌炎（主要是COVID-19）的其他潜在原因和因果关系评估的方法。
方法：使用Apulian地区出院表格档案来定义Apulia的心肌炎病例，考虑2017年至2022年的数据。通过从区域免疫数据库收集的数据评估患者的总体疫苗接种状态。SARS-CoV-2感染的病史是从意大利卫生研究所平台提取的。
结果：自2017年以来，Apulian受试者中记录了5,687例心肌炎；总体发病率呈下降趋势，在0-40岁的受试者中略有增加。从2021年到2022年，施用了2,930,276剂COVID-19mRNA疫苗；据报道，894名（0.03％）的普利亚居民在第二剂mRNA疫苗后诊断为心肌炎，发病率为17.9×1,000,000人-月。多变量分析，根据年龄调整，性别,潜在的医疗状况，和COVID-19的诊断表明，即使在年轻受试者中，mRNA疫苗也是心肌炎的保护因素(aOR=0.4；95CI=0.3-0.5)。
结论：暴露与结果之间的时间关联并不等同于因果关系。我们的研究强调了如何在该主题的研究中优先考虑考虑心肌炎（主要是COVID-19）的其他潜在原因和因果关系评估的方法。
