A secondary analysis shows that patients with at least one COVID-19 vaccine after experiencing an acute coronary syndrome (ACS) had similar rates of major adverse cardiovascular events (MACE) to unvaccinated patients. These data were reported by Henrique Andrade R. Fonseca, PhD, of the Instituto Israelita de Ensino e Pesquisa, São Paulo, and colleagues, in a manuscript published Wednesday online in JAMA Network Open. Hospitalizations and mortality are reduced thanks to the COVID-19 vaccines, but many unanswered questions remain about the incidence of cardiac events in secondary prevention populations. Patients at high risk for cardiovascular events who also received the COVID-19 vaccine have not been thoroughly studied. The VIP-ACS trial was a randomized, multicenter trial that investigated the efficacy of the influenza vaccine post-ACS between July 19, 2019, and Nov. 30, 2020 among patients in Brazil. It showed no difference in the primary outcome, a hierarchical composite of all-cause mortality, myocardial infarction, stroke, unstable angina, heart failure hospitalization, urgent coronary revascularization, and respiratory-related hospitalization, using a win-ratio analysis, between patients who received a double-dose quadrivalent influenza vaccine and those who received the standard-dose quadrivalent influenza vaccine. In this secondary analysis of the trial, patients who received the COVID-19 vaccine were compared to patients who did not receive the COVID-19 vaccine . No randomization to the COVID-19 vaccine took place. Patients were part of the COVID-19 vaccine group if they received at least one COVID-19 vaccine during the follow-up period. A total of 1,801 patients (median age=56.7 years, 30.3% female) were included in the main . Cardiopulmonary events did not occur in 1,665 patients in the first 90 days, and these patients were included in the primary analysis; 50.2% of these patients received at least one COVID-19 vaccine. Of the patients who received the COVID-19 vaccine, 63.9% received the Oxford/AstraZeneca dose during the follow-up period. The primary end point incidence per 100 patient-years was 9.37 in the unvaccinated group versus 4.81 in the COVID-19 vaccinated group (adjusted hazard ratio [aHR]=0.41, 95% confidence interval [CI]=0.18-0.94, p=0.12). COVID-19 vaccination did not significantly reduce the risk of MACE (aHR=0.32, 95% CI=0.07-1.53, p=0.60), all-cause death (aHR=0.29, 95% CI=0.09-0.91, p=0.12) or cardiovascular death (aHR=0.42, 95% CI=0.04-4.02, p>0.99). A sensitivity analysis was conducted and found similar results for the adjusted incidence of the primary endpoint (aHR=0.43, 95% CI=0.02-0.94, p=0.12) and all-cause death (aHR=0.30, 95% CI=0.10-0.89, p=0.12). Some limitations of this study include the lack of statistical power, no randomization for COVID-19 vaccination and the prespecified exploratory analysis design of the study. Unmeasured or confounding variables could have some influence on the findings. Overall, this analysis shows that patients who had recently experienced ACS and who received at least one COVID-19 vaccine dose during follow-up had comparable rates of MACE, all-cause death and cardiovascular death, to patients who did not receive COVID-19 vaccines. Fonseca and other authors of this research letter reported receiving funding not related to this study from AstraZeneca and other pharmaceutical companies that developed the COVID-19 vaccines. The study itself was supported by funding grants from the Brazilian Ministry of Health. Source: Fonseca HAR, Damiani LP, Monfardini F, et al. COVID-19 Vaccination and Cardiopulmonary Events After Acute Coronary Syndromes: A Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2024 May 30 (Article in Press). Image Credit: myskin – stock.adobe.com