Month: April 2022

Categories : Cardiovascular DiseaseTags :

Not all Dietary Fibre Equally Good at Preventing CVD

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Photo by Daria Shevtsova on Pexels

A study published in JAMA Network Open showed that cereal fibre but not fruit or vegetable fibre, was consistently associated with lower inflammation and lower CVD incidence. Until now there had been limited data on the link between fiber and inflammation among older adults, who have higher levels of inflammation compared with younger adults.

The research includes data from a large and well-characterised prospective cohort of elderly individuals, with detailed data on dietary intake, inflammation, and incidence of CVD. The research confirmed previously observed associations between dietary fibre and CVD and extended those investigations to include the source of the fibre, the relationship of fibre with multiple inflammatory markers, and to test whether inflammation mediated the relationship between dietary fibre and CVD.

Of the 4125 adults enrolled in the Cardiovascular Health Study from 1989 to 1990 participants received a food frequency questionnaire that was administered to those without prevalent CVD at enrollment and then were followed up visits for development CVD (stroke, myocardial infarction, and atherosclerotic cardiovascular death) through June 2015. Blood samples were assessed for markers of inflammation.

“Higher intakes of dietary fiber is associated with lower CVD risk. A common hypothesis has been that higher fiber intakes reduce inflammation, subsequently leading to lower CVD risk,” said Rupak Shivakoti, PhD. ‘With findings from this study, we are now learning that one particular type of dietary fiber — cereal fibre — but not fruit or vegetable fibre was associated with lower inflammation. With findings from this study we now are learning that cereal fiber has the potential to reduce inflammation and will need to be tested in future interventional studies.”

Although there are data to suggest that fibre in general might have anti-inflammatory effects by improving gut function, modifying diet and satiety (eg, reduced fat and total energy intake), and improving lipid and glucose profile metabolism, why cereal fibre but not vegetable or fruit fibre is associated with lower inflammation is not clear and warrants further investigation, noted Dr Shivakoti. Additionally, it is unclear whether it is the cereal fibre itself or other nutrients in foods rich in cereal fibre behind the observed relationships.

“Additionally, we learned that inflammation had only a modest role in mediating the observed inverse association between cereal fiber and CVD,” observed Dr Shivakoti. “This suggests that factors other than inflammation may play a larger role in the cereal fiber-associated reduction in CVD and will need to be tested in future interventions of specific populations.

Source: Columbia University’s Mailman School of Public Health

Categories : Cardiovascular Disease PaediatricsTags :

Cardiovascular Risk Factors in Childhood Predict Adulthood Risks

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By tracking more than 38 000 participants from childhood for fifty years, researchers have uncovered direct evidence that the five cardiovascular risk factors when present in childhood predicted cardiovascular risk in adulthood. 

Body mass index, blood pressure, cholesterol, triglycerides and youth smoking, particularly in combination in early childhood, were clinically linked with cardiovascular events that predict poor cardiovascular health in adults.

The international study conducted by the International Childhood Cardiovascular Consortium (i3C) and published in the New England Journal of Medicine, found that the increased cardiovascular risk began as early as 40 years of age.

Paper co-author Prof Terence Dwyer at the University of Oxford commented: “Despite the effect medical and surgical care have had on treating heart disease, achieving the greatest possible reduction in the heart disease burden will depend on including preventive strategies that commence in childhood.”

The findings confirm that prevention must start in childhood. “Longitudinal studies like these have been hampered by a lack of inclusion of comprehensive childhood data around body measurements, blood pressure, and blood lipids and a failure to follow-up at ages when cardiovascular disease becomes common.”

The study involved 38 589 participants from Australia, Finland and the US, who were followed from age 3-19 years for a period of 35-50 years. 

The results showed that increased risk for cardiovascular events was seen in over half the children, with those having the highest risk factor levels, at 9 times the risk for an event as for children with below average risk factors.

“While this evidence had not been available previously, the findings were not entirely surprising as it had been known for some time that children as young as five already showed early signs of fatty deposits in arteries. This new evidence justified a greater emphasis on programs to prevent the development of these risk factors in children. Clinicians and public health professionals should now start to focus on how this might best be achieved,” Prof Dwyer concluded.

Source: Murdoch Childrens Research Institute

Categories : COVIDTags :

Home Pulse Oximeters in COVID no Better Than Just Asking

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Photo by Mufid Majnun on Pexels

Self-measurement of oxygen levels with pulse oximeters is no better than just regularly asking patients with COVID if they are short of breath, according to new research published in the New England Journal of Medicine. Pulse oximeters have often been applied because of concerns that patients might not notice their blood oxygen levels sliding dangerously. 

However, people in Penn Medicine’s COVID Watch programme, which monitors patients recovering at home via automated text messaging, had the same outcomes whether they used oxygen-measuring devices or not.

“Compared to remotely monitoring shortness of breath with simple automated check-ins, we showed that the addition of pulse oximetry did not save more lives or keep more people out of the hospital,” said the study’s co-lead author, Anna Morgan, MD, medical director of the COVID Watch program and an assistant professor of General Internal Medicine. “And having a pulse oximeter didn’t even make patients feel less anxious.”

The COVID Watch was launched in March 2020 to remotely monitor COVID patients at home, with 28 500 people enrolled to date. Twice a day for two weeks, text messages were automatically sent to these patients asking how they felt and if they were having difficulty breathing. If patients indicated dyspnoea, the programme would alert a nurse to make contact and arrange care.

“The programme made it easy to identify the sickest patients who needed the hospital, and keep the others at home safely,” said David Asch, MD, executive director of the Center for Health Care Innovation and a professor of Medicine, Medical Ethics and Health Policy. “The programme was associated with a 68 percent reduction in mortality, saving a life approximately every three days during peak enrollment early in the pandemic.”

However it was not known if monitoring blood oxygen would help.

“Early in the pandemic, there was a prevalent theory that oxygen levels in the blood dropped before a COVID patient became symptomatic and short of breath,” said study co-lead author Kathleen Lee, MD. “Detecting this earlier with a home pulse oximeter might provide an opportunity to get patients who are on the cusp of deteriorating to the hospital faster and initiate time-sensitive therapies to improve outcomes.”

The use of pulse oximeters was so intuitively appealing that the process got adopted even before this trial, the first randomised trial to test whether it actually worked.

“Several health systems, and even states like Vermont and countries like the United Kingdom, have integrated pulse oximetry into the routine home management of patients with COVID, but there’s been scant evidence to show this strategy makes a difference,” said the research project’s principal investigator M. Kit Delgado, MD.

In this study, more than 2000 patients enrolled in COVID Watch between Nov. 29, 2020, and Feb. 5, 2021, were randomised to receive standard COVID Watch care or the same program with the addition of a pulse oximeter.

However, no statistical difference was seen in the main study measure, the average number of days enrolled patients spent alive and out of the hospital in the 30 days after they were enrolled. For patients with pulse oximeters, the measure was 29.4 days; for those without, it was 29.5, with no difference across racial liines. This was important as black patients are known to have had worse COVID outcomes and concerns had been raised about the accuracy of pulse oximeters in people with darker skin.
The researchers cautioned that the study focused on pulse oximeters in established programme of remote monitoring, and patients don’t have access to a system like COVID Watch or on-call clinicians, self-monitoring with pulse oximeters may still be a reasonable approach until there is evidence to the contrary.

“Overall, these findings suggest that a low-tech approach for remote monitoring systems based on symptoms is just as good as a more expensive one using additional devices. Automated text messaging is a great way for health systems to enable a small team of on-call nurses to manage large populations of patients with COVID,” said co-principal investigator, Krisda Chaiyachati, MD. “There are a lot of other medical conditions where the same kind of approach might really help.”

Source: University of Pennsylvania School of Medicine

Categories : COVID Obstetrics & GynaecologyTags :

Caesarean and Induced Deliveries Fell During Pandemic

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During the first few months of the COVID pandemic, premature births from caesarean and induced deliveries fell by 6.5% – and remained consistently lower throughout, according to research reported in the journal Pediatrics. This is likely a result of fewer prenatal visits due to lockdown and social distancing rules, the researchers suggested, and call into question how many such interventions are necessary.   

The study, the first to examine pandemic-era birth data at scale, raises questions about medical interventions in pregnancy and whether some decisions by doctors may result in unnecessary preterm deliveries, according to Assistant Professor Daniel Dench, the paper’s lead author.

“While much more research needs to be done, including understanding how these changes affected fetal deaths and how doctors triaged patient care by risk category during the pandemic, these are significant findings that should spark discussion in the medical community,” A/Prof Dench said.

In effect, the study begins to answer a question that never could have been resolved in a traditional experiment: What would happen to the rate of premature C-sections and induced deliveries if women didn’t see doctors as often, especially in person, during pregnancy?

Doing such a study would be unethical, but lockdown had a side effect of reducing prenatal care visits by more than a third, according to one analysis. That gave A/Prof Dench and colleagues an opportunity to evaluate the impacts, after all.

The researchers took records of nearly 39 million US births from 2010 to 2020, and compared them to expected premature births (born before 37 weeks) from March to December 2020. 

The researchers found that in March 2020, when lockdowns began in the US, preterm births from C-sections or induced deliveries immediately fell from the forecasted number by 0.4%. From March 2020 to December 2020, the number remained on average 0.35% below the predicted values. That translates to 350 fewer preterm C-sections and induced deliveries per 100 000 live births, or 10 000 fewer overall.

Before the pandemic, the number of preterm C-sections and induced deliveries had been rising. Spontaneous preterm births also fell by a small percentage in the first months of the pandemic, but much less than births involving those two factors. The number of full-term caesarean and induced deliveries increased.

“If you look at 1000 births in a single hospital, or even at 30 000 births across a hospital system, you wouldn’t be able to see the drop as clearly,” said A/Prof Dench. “The drop we detected is a huge change, but you might miss it in a small sample.”  

The researchers also corrected for seasonality, for example, preterm births are higher on average in February than in March, which helped them get a clearer picture of the data.

The research comes with caveats. Up to half of all preterm C-sections and induced deliveries are due to a ruptured membrane, which is a spontaneous cause. But in the data Dench and his team used, it’s impossible to distinguish these C-sections from the ones caused by doctors’ interventions. So, Dench and co-authors are seeking more detailed data to get a clearer picture of preterm deliveries.

Still, these findings are significant because the causes for preterm births are not always known.

“However, we know for certain that doctors’ interventions cause preterm delivery, and for good reason most of the time,” A/Prof Dench said. “So, when I saw the change in preterm births, I thought, if anything changed preterm delivery, it probably had to be some change in how doctors were treating patients.”

The researchers’ findings raise a critical question: Was the pre-pandemic level of doctor intervention necessary?

“It’s really about, how does this affect foetal health?” said A/Prof Dench. “Did doctors miss some false positives – did they just not deliver the babies that would have survived anyway? Or did they miss some babies that would die in the womb without intervention?”  

A/Prof Dench plans to use foetal death records from March 2020 to December 2020 to answer this question. If he finds no change in foetal deaths at the same time as the drop in preterm births, that could point to “false positives” in doctor intervention that can be avoided in the future. Learning which pregnancies required care during the pandemic and which ones didn’t could help doctors avoid unnecessary interventions in the future.  

“This is just the start of what I think will be an important line of research,” A/Prof Dench said.

Source: Georgia Institute of Technology

Categories : COVIDTags :

Increased Risk of DVT, Pulmonary Embolism, and Bleeding after COVID

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3D illustration of a thrombus. Credit: Mecder, CC BY-SA 4.0, via Wikimedia Commons

There is an increased risk of developing deep vein thrombosis (DVT) for six months after a COVID, a study published in the BMJ suggests, as well as increased risk of pulmonary embolism and bleeding for shorter periods. The risk was particularly evelated for those with severe COVID as well as those infected during the first wave.

This highlights the importance of COVID vaccination, the researchers said. While there has been concern over the risk of blood clots after vaccination, the risk is far smaller, according to a large study last year.

It had previously been observed that people who had COVID had an increased risk of blood clots, and the researchers wanted to find out when that risk returns to normal levels.

The researchers tracked the health of just over one million people in Sweden who tested positive for COVID between February 2020 and May 2021 in Sweden, comparing them against four million people age- and sex-matched non-infected individuals.

Adjusting for confounding factors such as comorbidities, cancer, surgery, long term anticoagulation treatment, previous venous thromboembolism, or previous bleeding event, the researchers found an increased risk of:

  • first DVT, for up to three months
  • first pulmonary embolism, for up to six months
  • first bleeding event, such as a stroke, for up to two months

Comparing blood clot risk after COVID to the normal level of risk, the results showed that:

  • four in every 10 000 COVID patients developed DVT compared with one in every 10 000 non-infected individuals
  • about 17 in every 10,000 COVID patients had a blood clot in the lung compared with fewer than one in every 10,000  non-infected individuals

The authors wrote that the increased risk of blood clots was higher in the first wave than later waves, probably because treatments improved during the pandemic and older patients were starting to be vaccinated by the second wave.

Pulmonary embolism risk in people with severe COVID was 290 times greater than normal, and seven times higher than normal after mild COVID. However, there was no increase in bleeding risk in mild cases.

“For unvaccinated individuals, that’s a really good reason to get a vaccine – the risk is so much higher than the risk from vaccines,” said principal study investigator Anne-Marie Fors Connolly, from Umea University in Sweden.
While COVID’s causing the blood clots cannot be proven in this study, the researchers have a number of theories on the mechanism. It could be the direct effect of the virus on the layer of cells which line blood vessels, an exaggerated inflammatory response to the virus, or the body making blood clots at inappropriate times.

Though vaccines are very effective against severe COVID, but less so against infection, especially with the Omicron variant. This means repeat symptomatic infections are commonplace.

Source: BBC News

Categories : Cancer Mental HealthTags :

Fear of Cancer Recurrence is Widespread in Survivors and Patients

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A recent analysis of published research found that more than half (59%) of cancer survivors and patients experience at least a moderate level of fear of cancer recurrence and that about one in five (19%) have a high level of fear. The findings, published in Psycho-Oncology, show women and younger people in particular have more fear of recurrence.

Cancer prevalence is increasing due to ageing populations, and more people are surviving cancer thanks to improved treatments. Managing fear of cancer recurrence (FCR) has been reported as one of the most important unmet needs for this growing group. FCR is defined as “fear, worry, or concern relating to the possibility that cancer will come back or progress”. Low levels of FCR can be helpful by promoting treatment compliance and healthy lifestyle adaptations. However, at clinical levels, FCR can limit quality of life and daily functioning and require professional help. Four features have been defined as key characteristics of clinical FCR: “(a) high levels of preoccupation; (b) high levels of worry; (c) that are persistent; and (d) hypervigilance to bodily symptoms”. It is important to address FCR, because FCR may also lead to increased healthcare costs14 and for most patients, it does not decrease over time without intervention.

The analysis, which is included 46 studies from 13 countries. Investigators found similar fear of cancer recurrence rates in survivors and patients. On average, younger people and women experienced more fear of cancer recurrence.

Additional research is needed to not only identify which patients desire support to address their fear of cancer recurrence but also to determine how to tailor interventions to different levels of fear and to individual needs and preferences.

“Knowing the prevalence and severity of fear of cancer recurrence for the general cancer population and for different subgroups is an important development, because it is essential for shaping healthcare provision, policy, and research on fear of cancer recurrence,” said lead author Yvonne Luigjes-Huizer, a PhD candidate at the Helen Dowling Institute and the University Medical Centre Utrecht, in the Netherlands.

Source: Wiley

Categories : Implants and Prostheses Neurodegenerative DiseasesTags :

Implant Helps Patient with Neurodegenerative Disease to Walk Again

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Patient takes steps with the help of an assistant. Credit: Jmmy Ravier & NeuroRestore

A woman bedridden for over a year due to a debilitating neurodegenerative disease was able to get up and walk again, thanks to an innovative electrical stimulation system which was able to raise her blood pressure on standing and prevent her fainting. The system was developed by a team headed by Professors Jocelyne Bloch and Grégoire Courtine, and was detailed in The New England Journal of Medicine.

Their system includes electronics implanted directly on the spinal cord to reactivate the neurons that regulate blood pressure, thereby preventing the patient from losing consciousness every time she’s in an upright position. This type of implant was already in use for the treatment of low blood pressure in tetraplegic patients.

The female patient in the study suffers from multiple system atrophy-parkinsonian type (MSA-P), a neurodegenerative disease that afflicts several parts of the nervous system, including the sympathetic nervous system. 

MSA-P leads to the loss of sympathetic neurons regulating blood pressure, which results in orthostatic hypotension, a dramatic blood pressure drop when patients are in an upright position, which in some cases results in fainting. This increases fall risks, limits mobility, and can eventually shorten life expectancy. Having to remain in a reclined position to avoid passing out severely impacts patients’ quality of life.

The implant consists of a set of electrodes connected to an electrical-impulse generator typically used to treat chronic pain. After implanting their device directly on the patient’s spinal cord, the researchers found an improvement in the body’s capacity to regulate blood pressure, enabling the patient to remain conscious for longer periods in an upright position and to begin physical therapy to walk again. After being bedridden for 18 months, the patient is now able to walk as far as 250 metres.

For Jocelyne Bloch, this marks an important step toward the treatment of degenerative diseases: “We’ve already seen how this type of therapy can be applied to patients with a spinal-cord injury. But now, we can explore applications in treating deficiencies resulting from neurodegeneration. This is the first time we’ve been able to improve blood-pressure regulation in people suffering from MSA.”

Grégoire Courtine added that “this technology was initially intended for pain relief, not for this kind of application. Going forward, we and our company Onward Medical plan to develop a system targeted specifically to orthostatic hypotension that can help people around the world struggling with this disorder.”

Source: Ecole Polytechnique Federale de Lausanne

Categories : NeurologyTags :

People with Epilepsy Live Significantly Shorter Lives

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Depiction of a human brain
Image by Fakurian Design on Unsplash

A Danish cohort study published in Brain shows that people with epilepsy live 10-12 years fewer than those without the condition, with a slightly greater reduction for men than women. The study researchers also found that excess mortality is particularly pronounced among people with epilepsy and mental disorders.

One of the most frequently occurring neurological diseases, epilepsy affects 50 million people worldwide, and is known to increase the risk of early death by three times.

“The significantly reduced life expectancy is found both in people who develop epilepsy as a result of an underlying condition, such as brain cancer or stroke, and in those who develop epilepsy without an obvious underlying cause,” explained Julie Werenberg Dreier, one of the researchers behind the study.

The average reduction in life expectancy was 12 years for men with epilepsy and 11 years for women. Among people with epilepsy and mental disorders life expectancy was on average reduced by up to 16 years.

“We discovered that the reduced life expectancy for people with epilepsy was related to a wide range of causes of death which don’t just include the neurological, but also cardiovascular diseases, psychiatric disorders, alcohol related conditions, accidents and suicide,” said Jakob Christensen, one of the researchers behind the study.

Researchers used Danish healthcare register to follow almost six million Danes, including more than 130 000 people with epilepsy.

“The large study has enabled detailed analyses of a range of different causes of death and, for the first time, we’ve been able to estimate the number of years lost due to individual causes of death in people with epilepsy. This is important information as it can be used to target preventive efforts in order to reduce the mortality gap that we currently see in people with epilepsy,” said Julie Werenberg Dreier.

The mortality rate among people with epilepsy is due to a wide range of different conditions that cut across virtually all medical specialities, the researchers said. There is therefore a need for a collective effort to reduce mortality.

“The alarming results provide important knowledge for all healthcare professionals who, in one way or another, come into contact with people with epilepsy — also when prioritising and allocating resources in the healthcare system. The results clearly show how serious a disease epilepsy can be, and the findings of the study should be used in the prioritisation and planning of preventive measures,” said Jakob Christensen, emphasising that the results confirm the tendencies that have been shown in a few smaller studies which have estimated reduction in life expectancy in people with epilepsy.

“The study should be followed up by additional research, for example into the questions of how medical treatment and recurring seizures affect life expectancy.”

Source: Aarhus University

Categories : Metabolic DisordersTags :

Weekly Prednisone Could Reduce Obesity and Help in Muscular Dystrophy

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Source: Pixabay CCO

In a study on obese mice fed a high-fat diet, receiving prednisone once weekly improved their exercise endurance and strength, and their reduced weight. The study was published in the Journal of Experimental Medicine. A previous study had found that weekly prednisone was helpful in muscular dystrophy.

“These studies were done in mice. However, if these same pathways hold true in humans, then once-weekly prednisone could benefit obesity,” explained senior author Dr Elizabeth McNally.

“Daily prednisone is known to promote obesity and even metabolic syndrome – a disorder with elevated blood lipids and blood sugar and weight gain,” Dr McNally said. “So, these results, in which we intermittently ‘pulse’ the animals with once-weekly prednisone, are strikingly different. Obesity is a major problem, and the idea that once-weekly prednisone could promote nutrient uptake into muscle might be an approach to treating obesity.”

The once-weekly prednisone, a glucocorticoid steroid, promoted nutrient uptake into the muscles. The researchers also found these mice had increased adiponectin levels, an adipocyte-secreted hormone involved in protecting against diabetes and insulin resistance. Mice that were already obese from eating a high-fat diet were also found to benefit after once-weekly prednisone, experiencing increased strength, running capacity and lower blood glucose.

Most knowledge on steroids like prednisone is derived from studies of daily doses of prednisone

“We see a very different outcome when it is taken once a week,” Dr McNally said. “We need to fine tune dosing to figure out the right amount to make this work in humans, but knowing adiponectin might be one marker could provide a hint at determining what the right human dose is.”

Dr McNally described the weekly dose as “a bolus, or spike, of nutrients going into your muscle.”

“We think there is something special about promoting this spike of nutrients into muscle intermittently, and that it may be an efficient way to improve lean body mass,” she added.

“What is exciting to me about this work is the finding that a simple change in the dosing frequency can transform glucocorticoid drugs from inducers to preventers of obesity,” said corresponding author Mattia Quattrocelli. “Chronic once-daily intake of these drugs is known to promote obesity. Here we show that dosing the same type of drug intermittently – in this case, once weekly – reverses this effect, promotes muscle metabolism and energy expenditure, and curtails the metabolic stress induced by a fat-rich diet.”

Many patients take prednisone daily for different immune conditions, which has side effects including weight gain and even muscle atrophy with weakness. Investigators want to determine whether patients can get the same immune benefit with intermittent prednisone dosing, which could be much more beneficial to the muscle.

Dr McNally’s team previously found that intermittent prednisone administration was helpful for muscular dystrophy, showing once weekly prednisone improved strength, recently reporting that a pilot trial in humans with muscular dystrophy in which one weekly dose of prednisone improved lean mass.

McNally wants to identify biomarkers most critical to measure a beneficial response to prednisone.

“If we can determine how to choose the right dose of prednisone that minimises atrophy factors and maximises positive markers like adiponectin, then we can really personalise the dosing of prednisone,” she said.

The group also recently showed that weekly prednisone uses strikingly different molecular pathways to strengthening the muscle in male versus female mice, based on a new study just published in the Journal of Clinical Investigation by Isabella Salamone, a graduate student in Dr McNally’s lab.

The benefits of weekly prednisone are linked to circadian rhythms, according to another new study published in Science Advances. Human cortisol and steroid levels spike early in the morning before awakening.

“If you don’t give the drug at the right time of day, you don’t get the response,” Quattrocelli said. “In mice, we obtained good effects with intermittent prednisone in muscle mass and function when we dose them at the beginning of their daytime. Mice have a circadian rhythm inverted to us, as they generally sleep during the daytime and are active at night. This could mean that the optimal dosing time for humans during the day could be in the late afternoon/early evening, but this needs to be appropriately tested.”

Conducting these studies in mice is a major limitation, Dr McNally said.

“While we are encouraged by the pilot study in humans with muscular dystrophy, mouse muscles have more fast-twitch fibres than humans, and slow-twitch muscle could be different,” Dr McNally said. “More studies are needed to try to better understand whether these same mechanisms work in human muscles.”

Source: Northwestern University

Categories : Cardiovascular Disease VaccinesTags :

In Flu Season, Vaccine Reduces Cardiovascular Events in Heart Failure

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Woman sneezing
Photo by Andrea Piacquadio on Unsplash

A randomised controlled trial showed that people with heart failure receiving an annual flu shot had lower rates of pneumonia and hospitalisation on a year-round basis and a reduction in major cardiovascular events during peak flu season – but not year-round.

The study, presented at the American College of Cardiology’s 71st Annual Scientific Session, is the first randomised controlled trial to assess the benefits of the flu vaccine in people with heart failure, who face a high risk of cardiovascular events. It was conducted in countries across Asia, Africa and the Middle East where getting a flu shot is not commonplace.

Lead author Mark Loeb, MD, said: “Although our prespecified endpoints were not significant, our data suggest that there’s a clinical benefit [to getting a flu shot] given the clear reduction in pneumonia, moderate reduction in hospitalisation and reduction in vascular events and deaths during periods of peak influenza. When taken together with previous trials and observational studies, the collective data demonstrate there is a substantial benefit to receiving a flu vaccine for people with heart failure.”

Heart failure is a condition in which the heart becomes too weak or stiff to pump blood effectively. Previous studies have shown that people with heart disease or cardiovascular risk factors face an elevated risk of complications when they contract influenza, but there has been a lack of evidence on whether flu vaccines can help to mitigate this risk specifically in people with heart failure.

The trial enrolled 5129 patients with heart failure in 10 countries where flu vaccines are not common. Participants did not routinely get flu shots and had previously received a flu shot no more than once during the three years preceding the trial. Participants were randomised to receive a flu shot or a placebo annually for up to three years, though they could still get a flu shot outside of the trial. Researchers tracked health outcomes for a median of 2.9 years. The trial’s primary endpoint was a composite of death from cardiovascular causes, non-fatal heart attack or non-fatal stroke. Its co-primary endpoint included a composite of any of these events plus hospitalisation for heart failure.

Overall, the composite primary endpoint occurred in 691 participants and 1470 experienced the composite co-primary endpoint. When analysed on a year-round basis there was no significant difference in the rates of these events between those who had received a flu vaccine and those who had not.

Separate analyses of hospitalisation, pneumonia and other respiratory outcomes however found that rates of pneumonia were 42% lower and hospitalisations were down 15% among those who received a flu shot.

The flu vaccine arm showed a significant reduction in the first primary endpoint, as well as reductions in all-cause death and cardiovascular death, when the analysis was limited to periods of peak influenza circulation. When influenza circulation was low, no significant difference was seen.

The researchers accounted for the differences in influenza circulation seasons. Based on these results, researchers said the flu vaccine did help to protect patients from influenza complications, including cardiovascular events.

“Many of the effects we found during peak flu circulation disappeared outside of it,” Dr Loeb said. “There’s no biological explanation for that other than influenza infections.”

While the study was conducted in countries where the flu vaccine is either not widely available or not common to receive, Dr Loeb said the results could likely be generalisable even in countries where flu vaccine uptake is higher. Study participants were allowed to get a flu vaccine outside of the study, but Dr Loeb said that there was no impact on the findings as very few did so. He added that the study was stopped early in four countries due to the COVID pandemic.

Loeb said that additional trials and large-scale observational studies could further clarify the health benefits of influenza vaccination in people with cardiovascular disease.

“I think this study offers an important message about vaccines generally – that it is important to do randomised controlled trials in populations that historically haven’t had a very high uptake of vaccines,” Dr Loeb said. “These types of [research] gaps have to be filled.”

Source: American College of Cardiology