Single COVID-19 vaccine dose fails to reduce major adverse CV events after acute coronary syndromes: JAMA

COVID-19 vaccines have proven effective in reducing hospitalizations and deaths due to the virus. However, their impact on preventing cardiopulmonary events in patients with a high risk of cardiovascular incidents remains unclear. This secondary analysis aimed to address this gap by utilizing data from the Vaccination Against Influenza to Prevent Cardiovascular Events After Acute Coronary Syndromes (VIP-ACS) trial.

The study was approved by the Comitê de Ética em Pesquisa-Hospital Israelita Albert Einstein, with informed written consent from all participants. It adhered to the CONSORT reporting guideline. The VIP-ACS trial, a multicenter study conducted between July 2019 and November 2020, assessed the efficacy of influenza vaccination post-ACS. For this analysis, researchers compared cardiopulmonary events between patients who received at least one COVID-19 vaccine dose and those who did not.

Participants were classified as COVID-19 vaccinated upon receiving at least one dose and subsequently censored from the unvaccinated group. To minimize immortal bias, a landmark analysis excluded patients with end points within 90 days of randomization.

End points included all-cause death, myocardial infarction, stroke, hospitalization for unstable angina, hospitalization for heart failure, urgent coronary revascularization, or hospitalization for respiratory infections. Secondary end points consisted of major adverse cardiovascular events (MACE). Adjusted Cox proportional hazard models were used for analysis, considering a P < .05 as significant.

• The study included 1,801 participants, with a median age of 56.7 years and 30.3% female.

• Among them, 292 individuals had a prior myocardial infarction, and 35.7% were active smokers.

• Of the 1,665 individuals who did not have cardiopulmonary events within the first 90 days, 50.2% received at least one COVID-19 vaccine dose.

• Most received the Oxford/AstraZeneca (ChAdOx1) viral vector vaccine.

• In the 90-day event-free follow-up analysis, the incidence of the primary end point was 9.37 events per 100 patient-years for unvaccinated individuals versus 4.81 events for vaccinated individuals (adjusted hazard ratio [aHR], 0.41; 95% CI, 0.18-0.94; P = .12).

• Vaccination did not significantly reduce MACE (aHR, 0.32; 95% CI, 0.07-1.53; P = .60), all-cause death (aHR, 0.29; 95% CI, 0.09-0.91; P = .12), or cardiovascular death (aHR, 0.42; 95% CI, 0.04-4.02; P > .99).

• A sensitivity analysis revealed similar findings: the adjusted incidence of the primary composite endpoint was (aHR, 0.43; 95% CI, 0.02-0.94; P = .12), and all-cause death was (aHR, 0.30; 95% CI, 0.10-0.89; P = .12).

In this analysis, receiving at least one COVID-19 vaccine dose post-ACS did not significantly affect the rates of primary composite end points or MACE compared to unvaccinated patients. This contrasts with retrospective studies indicating a short-term reduction in MACE risk post-COVID-19 vaccination.

COVID-19 vaccination did not significantly reduce cardiopulmonary events or major adverse cardiovascular events in high-risk cardiovascular patients post-ACS. These results highlight the need for further research to understand the role of COVID-19 vaccines in this population. Despite these findings, the study's limitations, including non-randomization for COVID-19 vaccines and insufficient statistical power, suggest caution in generalizing the results.

Reference:

Fonseca, H. A. R., Damiani, L. P., Monfardini, F., Zimerman, A., Rizzo, L. V., & Berwanger, O. (2024). COVID-19 vaccination and cardiopulmonary events after acute coronary syndromes: A secondary analysis of a randomized clinical trial. JAMA Network Open, 7(5), e2413946. https://doi.org/10.1001/jamanetworkopen.2024.13946