COVID-19 vaccination reduced the risk of heart failure (HF), venous thromboembolism (VTE), and arterial thrombosis/thromboembolism (ATE) for up to 1 year after SARS-CoV-2 infection, according to new research published in Heart.

“Findings from this study highlight yet another benefit of COVID-19 vaccination,” wrote investigators in the study published online March 12, 2024.

COVID-19 vaccines have been shown to be highly effective in reducing the severity of acute SARS-CoV-2 infection and recent research suggests that “COVID-19 vaccination could protect against cardiac and thromboembolic complications attributable to COVID-19,” wrote corresponding author Daniel Prieto-Alhambra, MD, MSc, PhD, University of Oxford, United Kingdom, and colleagues. “However, most studies did not include long-term complications and were conducted among specific populations.”

They continued: “Evidence is still scarce as to whether the combined effects of COVID-19 vaccines protecting against SARS-CoV-2 infection and reducing post-COVID-19 cardiac and thromboembolic outcomes, outweigh any risks of these complications potentially associated with vaccination.”

Therefore, Prieto-Alhambra and colleagues conducted a staggered cohort study using electronic health records of 10.17 million vaccinated and 10.39 million unvaccinated individuals aged 18 years or older with no previous SARS-CoV-2 infection or COVID-19 vaccine at baseline based on national COVID-19 vaccination campaigns in the United Kingdom, Spain, and Estonia from January 2021 to July 2021.

Researchers used vaccination status as a time-varying exposure and included all COVID-19 vaccines approved within the study period: ChAdOx1 (Oxford/AstraZeneca), BNT162b2 (BioNTech/Pfizer), Ad26.COV2.S (Janssen), and mRNA-1273 (Moderna).

Outcomes included HF, VTE, and ATE recorded in 4 different time periods following SARS-CoV-2 infection: 0–30 days (acute phase), 31–90 days, 91–180 days, and 181–365 days (post-acute phase), according to the study.

FINDINGS

Results showed that COVID-19 vaccination was associated with reduced risks of post-COVID-19 cardiac and thromboembolic outcomes in the acute (0-30 days) and post-acute (31-365 days) phase, with the effect being stronger in the acute phase.

Investigators noted that the meta-analytic sHR for post-COVID VTE was 0.22 (95% CI, 0.17–0.29), ATE was 0.53 (95% CI, 0.44-0.63), and HF was 0.45 (95% CI, 0.38-0.53) for 0-30 days, while in the 91-180 days sHR were 0.53 (95% CI, 0.40-0.70), 0.72 (95% CI, 0.58-0.88), and 0.61 (95% CI, 0.51-0.73), respectively.

“Vaccination against SARS-CoV-2 substantially reduced the risk of acute post-COVID-19 thromboembolic and cardiac complications, probably through a reduction in the risk of SARS-CoV-2 infection and the severity of COVID-19 disease due to vaccine-induced immunity,” concluded Prieto-Alhambra et al. “Further research is needed on the possible waning of the risk reduction over time and on the impact of booster vaccination.”

Source: Mercadé-Besora N, Li X, Kolde R, et al. The role of COVID-19 vaccines in preventing post-COVID-19 thromboembolic and cardiovascular complications. Heart. Published online March 12, 2024. doi:10.1136/heartjnl-2023-323483