麻豆传媒

Vaccination for COVID-19 after an acute coronary syndrome (ACS) event was not associated with better cardiopulmonary outcomes or fewer major adverse cardiovascular events, according to a secondary analysis of the Brazilian VIP-ACS trial.

Censoring the first 90 days post-vaccination in this non-randomized comparison, people with ACS who had received at least one COVID-19 vaccine dose had 4.81 cardiopulmonary events per 100 patient-years as compared with 9.37 among those not vaccinated, Henrique Fonseca, PhD, of the Hospital Israelita Albert Einstein in São Paulo, and colleagues reported in .

Despite the numerical difference in cardiopulmonary events between the two groups, the result did not reach statistical significance after adjustment for multiple comparison (P=0.12). Cardiopulmonary events included all-cause death, myocardial infarction (MI), stroke, urgent coronary revascularization, as well as hospitalization for unstable angina, heart failure, or respiratory infection.

Vaccination -- which was mostly with AstraZeneca's COVID shot, a vaccine never authorized in the U.S. -- also did not significantly reduce the secondary endpoint of major adverse cardiovascular events (MACE; P=0.60). There were 4.32 such cardiovascular death, MI, or stroke events per 100 patient-years in the unvaccinated group versus 1.19 events in the vaccinated group.

These prospective findings counter recent retrospective studies demonstrating a short-term reduction in MACE risk after COVID-19 vaccination, Fonseca and colleagues noted.

While an interesting study, it had some important limitations, commented Susan Cheng, MD, a cardiologist at Cedars-Sinai Medical Center in Los Angeles, who was not involved in the study. "It appears they conducted the study relatively early on in the pandemic in a relatively high-CV-risk group of people," she told 麻豆传媒. "So it may be hard to generalize results to a broader population and to where we are now in the post-pandemic or endemic era."

The study was also relatively underpowered, Cheng pointed out. "This is probably a key issue," she said, noting that there was at least some separation of the 360-day Kaplan-Meier event curves between the vaccinated and unvaccinated individuals, but the total sample size and number of events was quite small in the vaccinated group.

"As a clinician, I would say the results are interesting, although [they] would not change my practice of advising patients who have a high risk for cardiopulmonary events to obtain a COVID vaccination if they have not been recently infected with COVID," she added.

The primary aim of the multicenter was to investigate whether double-dose influenza vaccination during hospitalization for ACS would further reduce the risk of major cardiopulmonary events when compared with guideline-recommended standard-dose influenza vaccination. That randomized comparison -- conducted from July 19, 2019, and Nov. 30, 2020, at 25 centers in Brazil -- concluded that this strategy did not improve cardiopulmonary outcomes compared with standard-dose vaccination.

The prespecified secondary analysis examined COVID-19 vaccination, which was not randomly assigned. During the first 90 days after an ACS event, a total of 1,665 of the 1,801 trial participants did not experience a cardiopulmonary event and were included in the landmark analysis, which was designed to minimize ascertainment immortal bias.

Patients were followed to 360 days. About 30% were female, and the median age was 56.7 years. Approximately 16% had had prior myocardial infarction, and 36% were current smokers.

About half of the secondary analysis patients had received at least one COVID-19 vaccine dose, and at least one dose was the AstraZeneca ChAdOx1 shot for about 64% of these participants. That in early 2021. Other vaccines that were available in Brazil were the Chinese developed-Sinovac vaccine, Pfizer's BNT162b2 mRNA shot (Comirnaty), and Johnson & Johnson's Ad.26.COV2.S vaccine, which is no longer available in the U.S.

"Our results should not be generalized to other COVID-19 vaccines," the researchers cautioned.

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