After being suppressed during the COVID pandemic, influenza is again circulating and threatening the health of over 65s. But why are older people so more susceptible to the flu? A new study from the University of Michigan, published in Nature Communications, offers clues.
The study, led by first author Judy Chen, a PhD candidate, senior author Professor Daniel Goldstein, MD, and their team investigates why cells called alveolar macrophages, the first line of defence in the lungs, appear to be compromised with age.
Macrophages attack pathogens like the flu virus and reside in alveoli. Importantly, these cells appear to be lost with ageing.
Previous research by another group showed that when macrophages from an old mouse were put into a young mouse, and cells looked young again. “This drove us to believe that something in the environment of the lungs is contributing to this,” said Chen.
Signs pointed to a lipid immune modulator known as prostaglandin E2 (PGE2) with wide ranging effects, from labour induction in pregnancy to inflammation with arthritis. The study team discovered there is more PGE2 in the lungs with age. This increase in PGE2, Chen explained, acts on the macrophages in the lung, limiting their overall health and ability to generate.
The team suspects that the buildup of PGE2 is yet another marker of a biological process called senescence, which is often seen with age. Senescence serves as insurance against the runaway division of damaged cells; cells that are senescent are no longer able to replicate.
“One of the interesting things about these cells is they secrete a lot of inflammatory factors,” said Chen.
The study showed that with age, the cells lining the air sacs in the lungs become senescent, and these cells lead to increased production of PGE2 and suppression of the immune response.
To test the link between PGE2 and increased susceptibility to influenza, they treated older mice with a drug that blocks a PGE2 receptor. “The old mice that got that drug actually ended up having more alveolar macrophages and had better survival from influenza infection than older mice that did not get the drug,” said Chen.
The team plans to next investigate the various ways PGE2 affects lung macrophages as well as its potential role in inflammation throughout the body. “As we get older, we become more susceptible not only to influenza, but to other infections, cancers, autoimmune diseases as well.”
In a new Journal of the American Chemical Society paper, researchers describe how they are developing a new way for diabetes and cancer patients to manage their conditions by enabling drugs to be delivered in pill form instead of through injections.
Some drugs for these diseases are water soluble, so transporting them through the intestines, is not feasible and makes them impossible to administer orally. However, UCR scientists have created a chemical “tag” that can be added to these drugs, allowing them to enter blood circulation via the intestines.
This tag is composed of a small peptide. “Because they are relatively small molecules, you can chemically attach them to drugs, or other molecules of interest, and use them to deliver those drugs orally,” said research leader Min Xue, UC Riverside chemistry professor.
Xue’s laboratory was testing something unrelated when the researchers observed these peptides making their way into cells.
“We did not expect to find this peptide making its way into cells. It took us by surprise,” Xue said. “We always wanted to find this kind of chemical tag, and it finally happened serendipitously.”
This observation was unexpected, Xue said, because previously, the researchers believed that this type of delivery tag needed to carry positive charges to be accepted into the negatively charged cells. Their work with this neutral peptide tag, called EPP6, shows that belief was not accurate.
Testing the peptide’s ability to move through a body, the Xue group teamed up with Kai Chen’s group in the Keck School of Medicine at the University of Southern California and fed the peptide to mice. With PET scans, the team observed the peptide accumulating in the intestines, and documented its ultimate transfer into the animals’ organs via the blood.
Having proven the tag successfully navigated the circulatory systems through oral administration, the team now plans to demonstrate that the tag can do the same thing when attached to a selection of drugs. “Quite compelling preliminary results make us think we can push this further,” Xue said.
Many drugs, including insulin, must be injected. The researchers are hopeful their next set of experiments will change that, allowing them to add this tag to a wide variety of drugs and chemicals, changing the way those molecules move through the body.
“This discovery could lift a burden on people who are already burdened with illness,” Xue said.
Research from South Africa and the UK has found that people living with HIV have a significantly delayed internal body clock, consistent with the symptoms of jet lag. The findings, which appear in the Journal of Pineal Research, may explain some of the health problems experienced by people with HIV, and guide research towards improving their quality of life.
Researchers from the University of the Witwatersrand and University of Cape Town along with Northumbria and Surrey universities in the UK and studied people aged 45 years and above living in Mpumalanga province, where nearly one in four people is living with HIV. As such, the infection is endemic and does not associate with any difference in lifestyle.
They found that physiological daily rhythms, as measured by the hormone melatonin, were delayed by more than an hour on average in HIV positive participants. Their sleep cycle was also shorter, with researchers noting that their sleep started later and finished earlier.
This suggests the possibility that HIV infection may cause a circadian rhythm disorder similar to the disruption experienced in shift work or jet lag.
The authors believe that this body clock disruption may contribute significantly to the increased burden of health problems that people living with HIV are experiencing despite successful treatment, such as an increased risk of cardiovascular, metabolic, and psychiatric disorders.
Researchers believe there is a strong need for further funding to identify whether similar disruption to the body clock is experienced by younger people living with HIV in other countries.
“The participants living with HIV essentially experience the one-hour disruption associated with switching to daylight savings time, but every single morning,” says corresponding author Malcolm von Schantz, Professor of Chronobiology at Northumbria University.
“This happens in spite of the fact that essentially everybody is exposed to the same light-dark cycle. Our findings have important potential implications for the health and wellbeing of people living with HIV, especially given the well-established relationships between disrupted circadian rhythms and sleep deprivation.”
Senior author Dr Karine Scheuermaier of Wits University added: “This is very similar to the risk profile observed in shift workers. Understanding and mitigating this disruption may be an important step towards helping people living with HIV live healthier lives.”
“Our findings identify an urgent research topic,” says Xavier Gómez-Olivé, also from the University of the Witwatersrand, whose research grant funded the study. “The next step must be to establish if the same body clock disruption exists in people living with HIV who are younger and who live in other countries.”
Co-author Dale Rae, of the University of Cape Town, added “This is a great example of the importance of studying sleep in people living in Africa, and demonstrates how findings from this research can also be relevant to people anywhere in the world.”
Figure 1. The epidemiological curve of measles outbreak cases, Greater Sekhukhune and Mopani Districts, Limpopo province, September to November 2022 (*Two sporadic cases in Vhembe District are not included). Source: NICD
As of 10 November, the National Institute of Communicable Diseases reported 35 laboratory-confirmed measles cases in Limpopo, with 14 new cases on 8 and 9 November, all in Mopani district. Thus far, most of the laboratory-confirmed cases (25 of 35) fall within the 13 month to 9 year age range.
With these new cases, the Mopani district with 19 cases has overtaken the Greater Sekhukhune district which remains at 16 (see Figure 1). Only seven cases are known to be vaccinated; eight are either unvaccinated or partially vaccinated; vaccination status of the remaining 20 is unknown.
According to a recent study published in BMC Public Health, measles has been experiencing a resurgence in South Africa. Over 2015–16, measles had remained largely under the elimination target of under one case per million in South Africa, but rose above this threshold from 2017–2019. Cases fell below the threshold in 2020 with the onset of COVID, but the pandemic also saw normal vaccination efforts slipping. The article authors also noted a measles vaccine effectiveness of only 80% among 1–4 year olds, compared to the 95% rate found in large datasets.
Those cases reported in the Mopani district were in the Greater Giyani, Ba-Phalaborwa, and Ga-Kgapane sub-districts. Epidemiological investigations showed that in the Mopani district, two siblings with measles infection had contact with cases in the Greater Sekhukhune district when they travelled there for a family funeral.
While two cases were reported in Vhembe District, they were considered sporadic as they had not links to the other cases and are not included in the outbreak tally.
The laboratory-confirmed measles infections have been identified in 19 males and 16 females ranging in age from 6 months and 24 years in the Greater Sekhukhune district, while cases range from 2 to 42 years in the Mopani district (Table 1), with increasing cases in the 5–9 year age range. Two children were hospitalised but no deaths or other complications from measles have been reported.
According to the NICD, the affected districts are continuing with the public health response activities and tracing and vaccinating contacts. Measles catch-up doses are also being given to children who have missed vaccinations.
Unsafe sex, interpersonal violence, high body mass index (BMI), high systolic blood pressure, and alcohol consumption are the top risk factors for disease and death in South Africa, according to the Second Comparative Risk Assessment (SACRA2) study conducted by the South African Medical Research Council’s Burden of Disease (BOD) Research Unit in collaboration with a long list of researchers. The study was recently published in a series of 15 related articles in the South African Medical Journal.
The study differs from other assessments of what people in South Africa die of in that it focusses on risk factors rather than on the eventual cause of death. This is, for example, why the study considers factors like unsafe sex or high body mass index rather than HIV or diabetes.
According to a related policy brief, the aim of the study was “to quantify the contribution of 18 selected risk factors to identify areas of public health priority”. The idea is that policymakers can use these findings to address the underlying causes of death and disease in South Africa since the identified risk factors are considered to be modifiable.
“We have to reduce the underlying drivers of disease and death if we are to improve the health of South Africans,” said CEO and President of the SAMRC Professor Glenda Gray in a statement. “Knowing that this is possible, should strengthen our resolve to ensure that this is accomplished.”
Causes of lost DALYs
Rather than only looking at what people died of, the researchers estimated the lost disability-adjusted life years (DALYs) associated with various risk factors. The World Health Organization describes DALYs as “a time-based measure that combines years of life lost due to premature mortality (YLLs) and years of life lost due to time lived in states of less than full health, or years of healthy life lost due to disability (YLDs). One DALY represents the loss of the equivalent of one year of full health.”
The researchers calculated the proportion of the total burden of disease (measured as DALYs) that can be attributed to each of the 18 risk factors in South Africa in 2012. Unsafe sex was top of the list at 26.6%, followed by interpersonal violence at 8.5%, high body mass index at 6.9%, high systolic blood pressure at 5.8%, and alcohol consumption at 5.6%. There were some differences by sex, with alcohol consumption, for example, ranking third in males, while it ranked fifth overall.
“Improvements have been observed, in particular, the reductions in the burden attributable to household air pollution and water and sanitation,” read the policy brief. “On the other hand, shifts in cardiometabolic risk factors, particularly the rapid emergence of high fasting plasma glucose accompanied by increases in high systolic blood pressure and high BMI, can be seen as well as the increased impact of ambient air pollution.”
According to project lead and BOD Unit Director Professor Debbie Bradshaw, while unsafe sex and interpersonal violence remained high on South Africa’s risk profile for the study period, non-communicable diseases combined are at an all-time high and are highly likely to overtake unsafe sex and interpersonal violence as causes of death and disease in South Africa.
Findings only up to 2012
The SACRA2 findings cover the period from 2000 to 2012. One reason for it only being published now is that the study required access to a wide variety of data sources. “Each data set had to be evaluated to identify any weaknesses or possible bias so that we can develop a robust understanding [of] the trends in the risk factors. This is a painstaking task, involving a large number of scientists, and means that we have only been able to describe the trends for the period 2000 – 2012,” says Bradshaw.
While robust and more up-to-date estimates would likely only come from the next SACRA study, it seems likely that some of the trends identified in SACRA2 would have continued in the years since 2012. For example, findings from SACRA2 suggest that the burden attributable to unsafe sex peaked in 2006 and has been declining ever since, largely due to the provision of antiretroviral treatment. Evidence from other sources, such as Thembisa, the leading mathematical model of HIV in South Africa, suggests that the decline in HIV-related deaths and the increase in treatment coverage have continued in the years since 2012.
Bradshaw describes unsafe sex as a lack of condom use which leads to sexually transmitted infections (STIs) and the possible transmission of HIV.
“Condom use is very important. If we get rid of unsafe sex, we will see the number of people being infected with HIV and STIs being reduced,” she said. “It is important that these epidemic drivers are not neglected in the push towards meeting the 90-90-90 management targets for 2022 and the 95-95-95 targets by 2030. HIV communication programmes should continue to promote male circumcision and risk awareness in the context of non-marital relationships to prevent HIV transmission.” (The first 90/95 refers to the percentage of people living with HIV who are diagnosed, the second to the percentage of those diagnosed on treatment, and the third to the percentage of those on treatment who are virally suppressed.)
Interpersonal violence declining
As with unsafe sex, the trend with interpersonal violence in South Africa also appears to be downward, although, as Megan Prinsloo, a researcher at the SAMRC, and colleagues highlight in one of the 15 papers, it continues to be a leading public health problem for the country.
The researchers found that between 2000 and 2012, there was a decrease in the death rate associated with interpersonal violence from 100 per 100 000 to 71 per 100 000. There was also a decrease in lost DALYs attributable to interpersonal violence from an estimated 2 million in 2000 to 1.75 million in 2012.
“Further strengthening of existing laws pertaining to interpersonal violence, and other prevention measures are needed to intensify the prevention of violence, particularly gender-based violence,” the researchers wrote.
High BMI and high blood pressure
Image by Marcelo Leal on Unsplash
A high BMI is associated with several cardiovascular diseases, diabetes, and chronic kidney disease, among others. According to one of the SACRA2 papers, high BMI caused around 59 000 deaths in 2012. Over the study period, the burden was higher in males than in females. Type 2 diabetes was the leading cause of death attributable to high BMI in 2012, followed by hypertensive heart disease, haemorrhagic stroke, ischaemic heart disease, and ischaemic stroke.
The researchers found that the average BMI increased between 2000 and 2012 and accounted for a growing proportion of both total deaths and DALYs.
High systolic blood pressure is similarly linked to an increased risk of several conditions, including stroke and heart disease. According toa paper by Beatrice Nojilana, a senior research scientist at the SAMRC, and colleagues, the prevalence of hypertension in people aged 25 and older increased from 2000 to 2012 – 31% to 39% in men and 34% to 40% in women.
But there is some interesting nuance. In both men and women, age-standardised rates for deaths and DALYs associated with raised systolic blood pressure increased between 2000 and 2006 but decreased from 2006 to 2012.
High systolic blood pressure is estimated to have caused around 62 000 deaths in South Africa in 2012. Stroke (haemorrhagic and ischaemic), hypertensive heart disease, and ischaemic heart disease accounted for over 80% of the disease burden attributable to raised systolic blood pressure over the period.
Alcohol abuse
Source: Pixabay CC0
In another SACRA2 paper, Dr Richard Matzopoulos, chief specialist scientist at the SAMRC, and colleagues, point out that alcohol abuse has widespread effects on health and contributes to over 200 health conditions. They write that, although the pattern of heavy episodic drinking independently increases the risk for injuries and transmission of some infectious diseases, long-term average consumption is the fundamental predictor of risk for most conditions.
The researchers used data from 17 population surveys to estimate age- and sex-specific trends in alcohol consumption in the adult population of South Africa between 1998 and 2016. For each survey, they calculated sex- and age-specific estimates of the prevalence of drinkers and the distribution of individuals across consumption categories.
Among males, the prevalence of drinkers was found to have decreased between 1998 and 2009, from 56.2% to 50.6%, but had increased again by 2016. Among females, the prevalence of current drinkers rose slightly from 19% in 1998 to 20% in 2016.
Speaking to Spotlight, Matzopoulos stresses that alcohol abuse puts a heavy burden on the already strained health system. “When you enter the trauma unit at hospitals on weekends, all you can smell is alcohol,” he said.
He says in some of his research he has noted a shift where young females are engaging in heavy drinking and young males are engaging in binge drinking over weekends. “These patterns are alarming because alcohol abuse can lead to unsafe sex, which may lead to the transmission of HIV and STIs. Excessive alcohol use also has an impact on some NCDs and can compromise the immune system of a person who is on ARV treatment,” he said.
Matzopoulos said government can put in place policies such as the restriction of alcohol sales, banning alcohol advertising, and increasing the price of alcohol.
A reluctance to make eye contact is a hallmark of autism spectrum disorder (ASD). By simultaneously imaging the brains of people making eye contact, Yale University researchers found that eye contact between two individuals was associated with a specific area associated with social interaction, which synchronises when two people with normal neural development gaze at each other. The results, published in the journal PLOS ONE, showed that in people with ASD, there was less activity in this region when they attempted eye contact.
People with ASD have been showed to have reduced or altered neurological arousal from looking at images of faces or even robots. Although eye contact is a critically important part of social interactions, scientists have been limited in studying the neurological basis of live social interaction with eye-contact in ASD because of the inability to image the brains of two people simultaneously.
Now, using an innovative technology that enables imaging of two individuals during live and natural conditions, Yale researchers have identified specific brain areas in the dorsal parietal region of the brain associated with the social symptomatology of autism. The study finds that these neural responses to live face and eye-contact may provide a biomarker for the diagnosis of ASD as well as provide a test of the efficacy of treatments for autism.
“Our brains are hungry for information about other people, and we need to understand how these social mechanisms operate in the context of a real and interactive world in both typically developed individuals as well as individuals with ASD,” said co-corresponding author Joy Hirsch, Elizabeth Mears and House Jameson Professor of Psychiatry, Comparative Medicine, and of Neuroscience at Yale.
The Yale team, led by Hirsch and James McPartland, Harris Professor at the Yale Child Study Center, analysed brain activity during brief social interactions between pairs of adults – each including a typical participant and one with ASD – using functional near-infrared spectroscopy, a non-invasive optical neuroimaging method. Both participants were fitted with neuroimaging caps which measured brain activity during face gaze and eye-to-eye contact.
The investigators found that during eye contact, participants with ASD had significantly reduced activity in a brain region called the dorsal parietal cortex compared to those without ASD. Further, the more severe the overall social symptoms of ASD as measured by ADOS (Autism Diagnostic Observation Schedule, 2nd Edition) scores, the less activity was observed in this brain region. Neural activity in these regions was synchronous between typical participants during real eye-to-eye contact but not during gaze at a video face. This typical increase in neural coupling was not observed in ASD, and is consistent with the difficulties in social interactions.
“We now not only have a better understanding of the neurobiology of autism and social differences, but also of the underlying neural mechanisms that drive typical social connections,” Hirsch said.
According to a study published in JAMA Pediatrics, cases of young people seeking care for eating disorders greatly increased in the months of the pandemic.
Eating disorders (EDs), such as anorexia nervosa and bulimia nervosa, impact a wide range of individuals. In the developmental stages of adolescent and young adulthood, EDs – especially restrictive ones – can have particularly negative impacts. Furthermore, EDs commonly co-occur with other mental health conditions which can influence the trajectory of illness. Individuals with EDs have greater mortality rates, partly due to increased suicidality.
EDs requires intensive specialist care, which is not often available in many settings. A rise in rates of anxiety and depression have been attributed to the COVID pandemic, as well as a worsening of ED. Possible reasons for this include uncertainty about the future, disruptions in daily routines, inconsistent access to food, more time spent in triggering environments, influence from the media, and changes in access to treatment.
Reports from hospitals indicated increasing numbers of diagnoses and hospital admissions for ED, but there was little geographically widespread data.
Therefore, the researchers set out to investigate trends in patient volume for inpatient medical hospitalisation as well as volume of patients seeking outpatient subspecialty care, both before and after the pandemic.
The researchers used an an observational case series design to compare changes in volume in inpatient and outpatient ED-related care at 15 sites between January 2018 and December 2021.
Before the COVID pandemic, the relative number of pooled inpatient ED admissions were increasing over time by 0.7% per month. After onset of the pandemic, there was a significant increase in admissions over time of 7.2% per month through April 2021, then a decrease of 3.6% per month through December 2021. Before the pandemic, relative outpatient ED assessment volume was stable over time, with an immediate 39.7% decline in April 2020. Thereafter, new assessments increased by 8.1% per month through April 2021, then decreased by 1.5% per month through December 2021. The nonhospital-based ED program did not demonstrate a significant increase in the absolute number of admissions after onset of the pandemic but did see a significant increase of 8.2 additional inquiries for care per month in the first year after onset of the pandemic.
“Given inadequate ED care availability prior to the pandemic, the increased postpandemic demand will likely outstrip available resources. Results highlight the need to address ED workforce and program capacity issues as well as improve ED prevention strategies.”
As climate change continues to increase the severity, frequency and duration of heat wave, prisoners and prison workers are at greater mortality risk if their environment is not air conditioned, according to a new study on Texas prisons published in JAMA Network Open.
The study examined the relationship between heat exposure and mortality risks in Texas prisons, focusing on how these risks vary between prisons with air conditioning and those without it.
The researchers analysed data gathered between 2001 and 2019 showing that 271 people died due to extreme heat exposure during that timeframe.
Even a 1° Fahrenheit (0.56°C) increase above 85°F (29.4°C) can increase the daily mortality risk by 0.7%, the researchers found.
The research team combined data from the US Bureau of Justice Statistics on mortality in Texas prisons with temperature data from NASA and used a novel epidemiologic analysis to arrive at its findings. About 13% of mortality during warm months may be attributable to extreme heat in Texas prison facilities without air conditioning.
It is important to note that while an average of 14 people died each year from heat-related causes in Texas prisons without air conditioning, not a single heat-related death occurred in climate-controlled prisons, said lead study author Julie Skarha, recent PhD graduate.
“The majority of Texas prisons do not have universal air conditioning,” Skarha said. “And in these settings, we found a 30-fold increase in heat-related mortality when compared to estimates of heat-related mortality in the general US population.”
Study co-author Dr David Dosa, an associate professor of medicine at Brown, pointed out that heat is often a silent killer.
“We have seen similar situations in nursing homes, where heat isn’t reported on the death certificate,” said Dosa. “It’s only after we run these analyses that we can determine how much of a role heat played in someone’s death.”
The findings, the researchers said, suggest that an air conditioning policy for Texas prisons may be an important part of protecting the health of people living and working in these facilities.
In a new study published in Molecular Biology of the Cell, a team of Rensselaer Polytechnic Institute researchers identified a previously unknown propofol anaesthetic mechanism, which, despite its frequent clinical application, is poorly understood.The study found that propofol exposure impacted the transportation of proteins to the surface of neurons, interrupting their function.
Almost all animal cells, including human cells, are highly compartmentalised and rely on efficient movement of protein material between compartments in vesicles. This transport must be efficient and highly specific to maintain cellular organisation and function.
The research team was led by Dr Marvin Bentley, associate professor at Rensselaer Polytechnic Institute, whose laboratory studies vesicle transport in neurons. Neurons are particularly reliant on vesicle transport because axons, often organised in nerve bundles. can span distances of up to 100cm in humans. Errors in vesicle transport have been linked to neurodevelopmental and neurodegenerative diseases such as Alzheimer’s and Parkinson’s.
This new study found that propofol affects a family of proteins called kinesins – small ‘motor proteins’ that move vesicles on tiny filaments called microtubules.
Dr Bentley’s team observed that vesicle movement of two prominent kinesins, Kinesin-1 and Kinesin-3, was substantially reduced in cells exposed to propofol. The team then showed that propofol-induced transport delays led to a significant drop in protein delivery to axons.
“The mechanism by which propofol works is not fully understood,” Bentley said. “What we discovered was unexpected: propofol altered the trafficking of vesicles in live neurons.”
Overall, the research contributes significantly to our understanding of how propofol works. Most studies on propofol’s anaesthetic mechanism have instead focused on its interaction with an ion channel called the GABAA receptor, which inhibits neurotransmission when activated.
This new study demonstrates that vesicle transport is an additional mechanism that may be important for propofol’s anaesthetic effect. Discovery of this new propofol effect has important applications for human health and may lead to the development of better anaesthetic drugs.
A recent study comparing atrial fibrillation (AF) treatments, published in The New England Journal of Medicine, shows that early intervention with cryoballoon catheter ablation (cryoablation) is more effective at reducing the risk of serious long-term health impacts, when compared to the current first step in treatment, antiarrhythmic drugs.
“By treating patients with cryoablation right from the start, we see fewer people advancing to persistent, more life-threatening forms of atrial fibrillation,” says Dr Jason Andrade, an associate professor of medicine at University of British Columbia. “In the short term, this can mean less recurrences of arrhythmia, improved quality of life and fewer visits to the hospital. In the long run, this can translate into a reduced risk of stroke and other serious heart problems.”
When used for AF, cryoablation is a minimally invasive procedure that involves guiding a small tube into the heart to kill problematic tissue by freezing. Historically, the procedure has been reserved as a secondary treatment when patients don’t respond to antiarrhythmic drugs.
“This study adds to the growing body of evidence that early intervention with cryoablation may be a more effective initial therapy in the appropriate patients,” says Dr Andrade.
Early intervention halts disease progression
AF affects approximately 3% of the population, and while the condition starts as an isolated electrical disorder, each recurring incident can cause electrical and structural changes in the heart that can lead to persistent AF, where episodes last more than seven days.
“Atrial fibrillation is like a snowball rolling down a hill. With each atrial fibrillation episode there are progressive changes in the heart, and the heart rhythm problem gets worse,” explains Dr Andrade.
The new findings, stemming from a multi-site clinical trial, show that cryoablation can stop this snowball effect.
Researchers enrolled 303 patients with AF in Canada. Half of the patients were randomised to receive antiarrhythmic drugs, while the other half were treated with cryoablation. All patients received an implantable monitoring device that recorded their cardiac activity throughout the study period.
At three years follow-up, patients in the cryoablation group were less likely to progress to persistent AF compared to patients treated with antiarrhythmic drugs. Over the follow-up period, the cryoablation patients also had lower hospitalisation rates and experienced fewer serious adverse health events that resulted in death, functional disability or prolonged hospitalisation.
Addressing the root cause
Because cryoablation targets and destroys the cells that initiate and perpetuate AF, the researchers say it can lead to longer-lasting benefits.
“With cryoablation, we’re treating the cause of the condition, instead of using medications to cover-up the symptoms,” says Dr Andrade. “If we start with cryoablation, we may be able to fix atrial fibrillation early in its course.”
The new study builds on previous work by Dr Andrade and colleagues demonstrating that cryoablation was more effective than antiarrhythmic drugs at reducing the short-term recurrence of atrial fibrillation.
