P224: Assessment of Risk Factors for Myocarditis in the United States Using Integrated Electronic Health Records and Claims Data
Poster Presenter
Claudia Ana Ianos
Senior Director, Safety Risk Management Lead
Pfizer United States
Objectives
Analyze risk factors for myocarditis among patients after mRNA COVID-19 vaccination (Group 1); after SARS-CoV-2 infection (Group 2); and prior to the COVID-19 era (Group 3).
Method
In a nested case-control study using Optum® de-identified Electronic Health Record data, past medical history in myocarditis cases (identified via ICD-10 codes and validated by clinical note review with Brighton criteria) and matched non-myocarditis controls was assessed using multivariable models.
Results
Among myocarditis cases identified via ICD codes (=1 inpatient diagnosis or =2 outpatient diagnoses at least 30 days apart) from 01 Jan 2016 to 31 Mar 2023 with clinical notes available, the proportions of validated cases were 59/120 for Group 1, 335/435 for Group 2, and 160/245 for Group 3. Validated myocarditis patients were 37.3%, 45.7%, and 42.5% female, with median ages of 40, 52, and 46.5 years from groups 1, 2 and 3, respectively. In multivariable logistic regression models that adjusted for demographics and clinical variables, higher odds of myocarditis were observed across all three groups for African American race (odds ratio [OR]: 1.37-2.52; p-value: <0.001-0.263) compared to White race, Hispanic ethnicity (OR: 1.52-5.21; p-value: 0.012-0.064) compared to non-Hispanic ethnicity, and those with a recent (within 182 days) in-patient hospitalization prior to the myocarditis diagnosis or matched control date (OR: 2.28-5.57; p-value: <0.001-0.001) compared to no in-patient hospitalization. Lower odds of myocarditis were observed across all three groups for residence in the Midwest (OR: 0.230-0.480; p-value: <0.001-0.068), South (OR: 0.248-0.664; p-value: <0.001-0.019) and West regions (OR: 0.184-0.309; p-value: <0.001-0.177) compared to the Northeast, and for unknown or undefined insurance status (OR: 0.159-0.330; p-value: <0.001) compared to commercial insurance. Myocarditis was also associated with a prior history of heart conditions including cardiomyopathies (OR: 2.62-16. 7; p-value: <0.001-0.032), heart failure (OR: 1.49-15.6; p-value: <0.001-0.07), and cardiomegaly (OR: 1.57-5.44; p-value: 0.001-0.021) in all three groups.
Conclusion
In this study, myocarditis patients were more likely to have had an in-patient hospitalization in the past 182 days and prior history of heart conditions including cardiomyopathies, heart failure, and cardiomegaly, across all study groups ( after mRNA COVID-19 vaccination, after SARS-CoV-2 infection, and prior to the COVID-19 era), which suggests that individuals diagnosed with myocarditis may have prevailing risk factors. This natural history study of patients’ longitudinal journey that captures adequate medical history can serve to advance the knowledge of myocarditis of various etiologies as well as identifying potential risk factors for myocarditis after mRNA COVID-19 vaccination, after SARS-CoV-2 infection, and prior to the COVID-19 era in order to contextualize and mitigate safety events while providing public health insights.
