The impact of COVID-19 vaccination on patients with congenital heart disease in England: a case-control study.

Background: Studies predating widespread COVID-19 vaccination identified patients with congenital heart disease (CHD) as a group at increased risk of severe outcomes from COVID-19. Here we evaluate the impact of vaccination on COVID-19 outcomes among patients with CHD.

Methods: We conducted a case-control study using linked English electronic health records (n=3 18 135). Patients with CHD were matched with controls by age, sex, ethnicity and GP practice. The 'prevaccination' cohort comprised unvaccinated patients with CHD and matched controls with first-recorded SARS-CoV-2 infection between 1 March and 8 December 2020 (7805 cases, 27 620 controls). The 'post-vaccination' cohort comprised vaccinated patients with CHD and matched controls with first-recorded SARS-CoV-2 infection between 1 March 2021 and 1 April 2022, at least 14 days after vaccination (57 550 cases, 225 160 controls). Odds of severe COVID-19 outcomes were compared using conditional logistic regression. We also compared the rate at which vaccine efficacy diminished, and the incidence of vaccine-associated complications.

Results: Compared with the prevaccination cohort, postvaccination patients with CHD exhibited markedly reduced rates of COVID-19-related hospitalisation (0.5% vs 15.8%) and mortality rates (0.5% vs 4.6%). Compared with vaccinated controls, vaccinated patients with CHD remained at increased risk of hospitalisation (0.5% vs 0.2%, adjusted OR 2.24 (1.88-2.65); p<0.001) and death (0.5% vs 0.3%, adjusted OR 1.81 (1.54-2.13); p<0.001). There was no evidence that vaccine efficacy declined faster in patients with CHD, or that patients with CHD experienced a larger increase in incidence of myocarditis, pericarditis or thrombotic events.

Conclusion: We observed a lower absolute risk of hospitalisation and death from COVID-19 in CHD patients after vaccination. However, in vaccinated CHD patients, an elevated risk of severe outcomes persists compared with vaccinated people without CHD. These results emphasise the importance of vaccination in the CHD population, and of vigilance among care providers dealing with COVID-19 infection in CHD patients, even if fully vaccinated.