Thrombosis Development After mRNA COVID-19 Vaccine Administration: A Case Series
Study Says COVID-19 Vaccines Can Reduce Risk Of Heart Failure, Blood Clots Following Infection
COVID-19 vaccination was associated with reduced risks of acute and post–acute COVID-19 heart failure, venous thromboembolism, and arterial thrombosis/thromboembolism.
A recent study revealed that COVID-19 vaccines reduce the likelihood of heart failure (HF) by as much as 55% and blood clot formation by up to 78% after COVID-19 infection.
COVID-19 vaccineImage credit: Leigh Prather – stock.Adobe.Com
Published in BMJ Heart, the study found that COVID-19 vaccination was associated with reduced risks of acute (30-day) HF by 55%, venous thromboembolism (VTE) by 78%, and arterial thrombosis/thromboembolism (ATE) by 47%. These reduced risks are in comparison with patients who were not vaccinated against COVID-19.
"In line with previous studies, our findings suggest a potential benefit of vaccination in reducing the risk of post–COVID-19 thromboembolic and cardiac complications," the researchers said.
The staggered cohort study included a total of 10.17 million vaccinated and 10.39 million unvaccinated individuals from the United Kingdom, Spain, and Estonia. Subdistribution hazard ratios (sHRs) were estimated using Fine-Gray models, and random-effect meta-analyses were conducted across staggered cohorts and databases.
Looking forward to the postacute phases—31 to 90 days, 91 to 180 days, and 181 to 365 days post COVID-19 infection—HF and VTE both saw slight dips in reduced risks at 180 days, which went back up slightly at the 365-day mark. Reduced risks remained notable.
For HF, a 39% reduced risk persisted at 90 days and 180 days, which then went back up to a 48% reduced risk at 1 year after COVID-19 infection. For VTE in the postacute phase, patients had a 57% reduced risk at 90 days, dropping to 47% at 180 days, with a slight uptick to a 50% reduced risk at 1 year.
The researchers saw a slightly different trend with ATE. After dropping from a 47% 30-day risk to a 26% 90-day risk, the postacute reduced risk associated with COVID-19 vaccination increased to 28% at 180 days, increasing to a 38% reduced risk at 1 year post infection.
The researchers included post–COVID-19 outcome events based on previous research. Among these were myocarditis/pericarditis (MP), ventricular arrhythmia/cardiac arrest (VACA), deep vein thrombosis (DVT), pulmonary embolism (PE), ischemic stroke (IS), and myocardial infarction (MI). All of these saw reduced risks in the 30-day acute phase for vaccinated individuals.
Compared with unvaccinated individuals, meta-analytic estimates in the acute phase showed sHRs of:
The study has limitations inherent to real-world data, such as data quality issues and potential confounding factors. Despite using advanced methods like large-scale propensity score weighting and calibration, the researchers said there may have still been residual bias. Under-reporting of post–COVID-19 complications—particularly in primary care databases without hospital linkage—could also affect the accuracy of outcomes, but results from databases including secondary care data showed similar trends. Additionally, the study included a small number of young men and male teenagers, a population of interest due to concerns about increased risks of myocarditis/pericarditis following vaccination.
"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," the researchers concluded. "Findings from this study highlight yet another benefit of COVID-19 vaccination. However, further research is needed on the possible waning of the risk reduction over time and on the impact of booster vaccination."
Reference
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
Deep Vein Thrombosis
Content
Deep vein thrombosis (DVT) is a blood clot (thrombus) in a deep vein, usually in the legs. These clots require medical care right away.
These clots are dangerous because they can break loose, travel through the bloodstream to the lungs, and block blood flow in the lungs (pulmonary embolism). Pulmonary embolism is often life-threatening. DVT can also lead to long-lasting problems. It may damage the vein and cause the leg to ache, swell, and change color.
Clots can also form in superficial veins. Blood clots with inflammation in superficial veins (called superficial thrombophlebitis or phlebitis) rarely cause serious problems.
Blood clots most often form in the calf and thigh veins, and less often in the arm veins or pelvic veins. Diagnosis and treatment of DVT in other parts of the body are similar.
Dr John Campbell Says Oxford AstraZeneca Covid Vaccine Is Safe
CUMBRIAN health heavyweights have moved to quell concerns over AstraZeneca's Covid vaccine after blood clot fears were raised.
Colin Cox, the county's director of public health, and Dr John Campbell, an academic from Carlisle, have described the decision of nations like Germany, France, Italy and Spain, to halt jabs, as 'strange' and 'baffling'.
More than 17m people in the UK and EU already had the jab, with 15 cases of deep vein thrombosis and 22 cases of pulmonary embolism reported, as of March 8.
In a YouTube talk on Monday, Dr Campbell, a former A&E volunteer and nurse lecturer, said the data in the public domain suggests the vaccine could even have a "protective effect" against blood clots.
He said that information provided on the normal the incident rate stood at about 120 per 100,000 population — which is broken down to a rate of 130 for men and 110 for women.
Dr Campbell added: "The data is that from a much larger population size.
"While it is right to look at the data, it does not seem to be surprising."
After the talk he said the data "does look a bit strange".
In a statement yesterday, Mr Cox said: "The decision of a number of countries to suspend use of the AstraZeneca vaccine is baffling.
"There have been 37 reports of blood clots following over 17m doses of the vaccine being given — that's actually a lower incidence of blood clotting than you'd expect to see just by chance, so there's absolutely no evidence that the vaccine can cause blood clots."
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