BACKGROUND AND PURPOSE:

• It is unclear whether COVID-19 vaccines prevent secondary complications of COVID (e.g. acute myocardial infarction (AMI) and ischemic stroke) in those who do become infected despite vaccination
• Kim et al. (JAMA, 2022) examined the association between vaccination and AMI and ischemic stroke after COVID-19 infection

METHODS:

• Retrospective cohort study
  • Korean nationwide registry
• Population
  • Adults who were diagnosed with COVID-19, including asymptomatic infections, between July 2020 and December 2021
• Exposure
  • Full vaccination (2 doses of mRNA or viral vector vaccine)
  • Never vaccinated
• Study design
  • Logistic regression and Cox proportional hazards modeling used, with adjustment for age, sex, Charlson Comorbidity Index, hypertension, and insurance type
• Primary outcome
  • Composite of hospitalizations for AMI and ischemic stroke that occurred 31 to 120 days after COVID-19 diagnosis

RESULTS:

• Never vaccinated: 62,727 | Fully vaccinated: 168,310
  • Fully vaccinated cohort
    • Was older and had more comorbidities
    • Had fewer cases of severe or critical COVID-19
• Incidence of composite outcome
  • Unvaccinated: 6.18 per 1,000,000 person-days
  • Fully vaccinated: 5.49 per 1,000,000 person-days
• Adjusted risk using hazard ratio (HR) of the composite outcome was significantly lower in the fully vaccinated group
  • aHR 0.42 (95% CI, 0.29 to 0.62)
• Adjusted risk was significantly lower in fully vaccinated patients for both
  • AMI: aHR 0.48 (95% CI, 0.25 to 0.94)
  • Ischemic stroke: aHR 0.40 (95% CI, 0.26 to 0.63)

CONCLUSION:

• Compared to no vaccination, full COVID-19 vaccination was associated with a reduced risk for acute myocardial infarction and ischemic stroke in individuals who become infected
• The authors state

A lower risk for outcome events in fully vaccinated patients was observed in all subgroups, although some did not reach statistical significance, including those with severe or critical infection

Learn More – Primary Sources:

Association Between Vaccination and Acute Myocardial Infarction and Ischemic Stroke After COVID-19 Infection