Tag: atrial fibrillation

Categories : Cardiovascular DiseaseTags :

Clinical Researchers Discover Four New Factors that Predict Atrial Fibrillation

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UK researchers have developed a new way of identifying patients at risk of atrial fibrillation (AF). While not life threatening, the condition increases people’s risk of having a transient ischaemic attack (TIA) or stroke by up to five times. A new study, published in the European Journal of Preventive Cardiology, reveals four specific factors that can predict which patients will have atrial fibrillation.

The researchers investigated clinical and echocardiographic parameters for AF and found that the combination of advanced age, increased DBP, increasing lateral PA (time interval from the beginning of the P wave on the surface electrocardiogram to the beginning of the A′ wave on pulsed wave tissue Doppler of the lateral mitral annulus), and impaired LA reservoir strain is associated with AF. Other studies have linked most of these factors have been linked with an increased risk of AF in stroke survivors.

The team went on to create an easy tool for doctors to use in practice to identify those at high risk, which they hope will help diagnose and treat more patients, reducing their risk of future strokes.

Lead researcher Prof Vassilios Vassiliou, from UEA’s Norwich Medical School and Honorary Consultant Cardiologist at the Norfolk and Norwich University Hospital, said: “Identifying who is at high risk and more likely to develop atrial fibrillation is very important.

“This is because it requires specific treatment with anticoagulants, commonly known as blood thinners, to reduce the risk of future strokes.

“Patients who have had a stroke usually undergo multiple investigations to determine the cause of the stroke, as this can influence the treatment they receive long-term.

“These investigations include prolonged monitoring of the heart rhythm with a small implantable device called a loop recorder, and an ultrasound of the heart, called an echocardiogram.”

The research team collected data from 323 patients across the East of England, treated at Cambridge University Hospitals NHS Foundation Trust, who had had a stroke with no cause identified- known as Embolic Stroke of Undetermined Source.

They analysed medical records as well as data from prolonged heart rhythm monitoring. They also studied their echocardiograms.

Prof Vassiliou said: “We determined how many of these patients were found to have atrial fibrillation up to three years following their stroke, and went on to perform a thorough assessment to identify if there are specific parameters that are connected with atrial fibrillation identification.

“We identified four parameters that were linked with the development of atrial fibrillation, which were consistently present in patients that had this arrhythmia. We then developed a model that can be used to predict who will show atrial fibrillation in the next three years, and is therefore at increased risk of another stroke in the future.”

“This is a very easy tool that any doctor can use in clinical practice,” he added.

“And it can potentially help doctors provide more targeted and effective treatment to these patients, ultimately aiming to highlight the people at higher risk of this arrhythmia that can benefit from prolonged heart rhythm monitoring and earlier anticoagulation to prevent a future stroke.”

Source: University of East Anglia

Categories : Cardiovascular Disease ExerciseTags :

Even Moderate Physical Fitness Protects Against Atrial Fibrillation and Stroke

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Photo by Barbara Olsen on Pexels

A study in more than 15 000 people has found that even moderate physical fitness is linked with a lower likelihood of developing atrial fibrillation and stroke. Progressively higher levels of fitness also reduced the risk of cardiovascular events. The research is presented at ESC Congress 2023.

Atrial fibrillation is the most common heart rhythm disorder, and patients with the condition have a five-fold higher risk of stroke than their peers. This study examined whether fitness was related to the likelihood of developing atrial fibrillation.

The study included 15 450 individuals without atrial fibrillation who were referred for a treadmill test between 2003 and 2012. The average age was 55 years and 59% were men. Fitness was assessed using the Bruce protocol, where participants are asked to walk faster and at a steeper grade in successive three-minute stages. Fitness was calculated according to the rate of energy expenditure the participants achieved, which was expressed in metabolic equivalents (METs).

Participants were followed for new-onset atrial fibrillation, stroke, myocardial infarction and death. The researchers analysed the associations between fitness and atrial fibrillation, stroke and major adverse cardiovascular events (MACE; a composite of stroke, myocardial infarction and death) after adjusting for factors that could influence the relationships including age, sex, cholesterol level, kidney function, prior stroke, hypertension and medications.

During a median of 137 months, 515 participants (3.3%) developed atrial fibrillation. Each one MET increase on the treadmill test was associated with an 8% lower risk of atrial fibrillation, 12% lower risk of stroke and 14% lower risk of MACE.

Participants were divided into three fitness levels according to METs achieved during the treadmill test: low (less than 8.57 METs), medium (8.57 to 10.72) and high (more than 10.72). The probability of remaining free from atrial fibrillation over a five-year period was 97.1%, 98.4% and 98.4% in the low, medium and high fitness groups, respectively.

Study author Dr Shih-Hsien Sung of the National Yang Ming Chiao Tung University, Taipei, Taiwan said: “This was a large study with an objective measurement of fitness and more than 11 years of follow up. The findings indicate that keeping fit may help prevent atrial fibrillation and stroke.”

Source: European Society of Cardiology

Categories : Ageing Cardiovascular DiseaseTags :

Stressful Life Events Contribute to Atrial Fibrillation Risk in Postmenopausal Women

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An estimated 1 in 4 postmenopausal women may develop atrial fibrillation in their lifetime, with stressful life events and insomnia being major contributing factors, according to new research published in the Journal of the American Heart Association.

Atrial fibrillation may lead to blood clots, stroke, heart failure or other cardiovascular complications. It primarily affects older adults.

“In my general cardiology practice, I see many postmenopausal women with picture perfect physical health who struggle with poor sleep and negative psychological emotional feelings or experience, which we now know may put them at risk for developing atrial fibrillation,” said lead study author Susan X. Zhao, M.D., a cardiologist at Santa Clara Valley Medical Center in California. “I strongly believe that in addition to age, genetic and other heart-health related risk factors, psychosocial factors are the missing piece to the puzzle of the genesis of atrial fibrillation.“

Researchers reviewed data from more than 83 000 questionnaires by women ages 50-79 from the Women’s Health Initiative, a major US study. Participants were asked a series of questions in key categories: stressful life events, their sense of optimism, social support and insomnia. Questions about stressful life events addressed topics such as loss of a loved one; illness; divorce; financial pressure; and domestic, verbal, physical or sexual abuse. Questions about sleeping habits focused on if participants had trouble falling asleep, wake up several times during the night and  overall sleep quality, for example. Questions about participants’ outlook on life and social supports addressed having friends to talk with during and about difficult or stressful situations; a sense of optimism such as believing good things are on the horizon; and having help with daily chores.

During approximately a decade of follow-up, the study found:

  • About 25% or 23 954 women developed atrial fibrillation.
  • A two-cluster system (the stress cluster and the strain cluster).
  • For each additional point on the insomnia scale, there is a 4% higher likelihood of developing atrial fibrillation. Similarly, for each additional point on the stressful life event scale, there is a 2% higher likelihood of having atrial fibrillation.

“The heart and brain connection has been long established in many conditions,” Zhao said. “Atrial fibrillation is a disease of the electrical conduction system and is prone to hormonal changes stemming from stress and poor sleep. These common pathways likely underpin the association between stress and insomnia with atrial fibrillation.”

Researchers noted that stressful life events, poor sleep and feelings, such as depression, anxiety or feeling overwhelmed by one’s circumstances, are often interrelated. It’s difficult to know whether these factors accumulate gradually over the years to increase the risk of atrial fibrillation as women age.

Chronic stress has not been consistently associated with atrial fibrillation, and the researchers note that a limitation of their study is that it relied on patient questionnaires from the start of the study. Stressful life events, however, though significant and traumatic, may not be long lasting, Zhao notes. Further research is needed to confirm these associations and evaluate whether customised stress-relieving interventions may modify atrial fibrillation risk.

Source: EurekAlert!

Categories : Cardiovascular Disease Diet and NutritionTags :

Five Years of High-dose Vitamin D Reduced Atrial Fibrillation Risk

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Taking higher-than-recommended doses of vitamin D for five years reduced the risk of atrial fibrillation in older adults, according to a randomised controlled study conducted in Finland and published in the American Heart Journal.

Atrial fibrillation is the most common arrhythmia, the risk of which increases with age, and which is associated with an increased risk of stroke, heart failure and mortality. Vitamin D has been shown to have an effect, for example, on the atrial structure and the electrical function of the heart, suggesting that vitamin D might prevent atrial fibrillation.

Conducted at the University of Eastern Finland in 2012–2018, the main objective of the Finnish Vitamin D Trial (FIND) was to explore the associations of vitamin D supplementation with the incidence of cardiovascular diseases and cancers. The five-year study involved 2 495 participants, men aged 60 and older, and women aged 65 and older, who were randomised into three groups: one placebo group and two vitamin D3 supplementation groups, with one of the groups taking a supplement of 40µg (1600 IU) per day, and the other a supplement of 80µg (3200 IU) per day. All participants were also allowed to take their personal vitamin D supplement, up to 20µg (800 IU) per day, which at the beginning of the study was the recommended dose for this age group. Participants had no diagnoses of cardiovascular disease or cancer at baseline, and they completed comprehensive health-related questionnaires, both at the beginning. Data on the occurrence of diseases and deaths were also obtained from Finnish nationwide health registers. Approximately 20% of participants were randomly selected for more detailed examinations and blood samples.

During the five-year study, 190 participants were diagnosed with atrial fibrillation: 76 in the placebo group, 59 in the 40µg group, and 55 in the 80 micrograms group. The risk of atrial fibrillation was 27% lower in the 40µg group, and 32% lower in the 80 micrograms group, when compared to the placebo group. In the sub-cohort selected for more detailed examinations, the mean baseline serum calcidiol concentration, which is a marker of the body’s vitamin D concentration, was relatively high, 75nmol/l. After one year, the mean calcidiol concentration was 100nmol/L in the 40µg group, and 120nmol/l in the 80µg group. No significant change in the calcidiol concentration was observed in the placebo group.

Only two randomised trials tried to test whether vitamin D supplementation reduces AF risk in healthy adults, and they did not observe an effect when using doses of 10µg (400 IU) or 50µg (2000 IU) per day. Further confirmation of the present results from the FIND study is therefore needed before doses of vitamin D that significantly exceed current recommendations can be recommended for preventing atrial fibrillation. The FIND study has previously published findings showing no association with the incidence of other cardiovascular events or cancers.

Source: University of Eastern Finland

Categories : Cardiovascular DiseaseTags :

Can We Use Light Instead of Shocks to Treat Atrial Fibrillation?

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New research published in the Journal of Internal Medicine demonstrates that optogenetics, a technique which uses light-sensitive proteins to control the activity of targeted cells. is a promising shock-free approach to treating atrial fibrillation (AF), or an irregular, often rapid heart rate, for immediate restoration of regular rhythm.

Current treatments for AF, which include medications and shocks to restore a regular heart rhythm, come with low success rates and/or serious side effects. In this new study, rats’ hearts were optogenetically modified to express light-gated ion channels. After AF was induced, the animals’ chests were illuminated resulting in acute restoration of regulation rhythm. This shows that sufficient light penetrated the chest wall, which suggests that full penetration of the human atrial wall may be feasible as well, if deemed necessary for clinical translation.

“Shock-free cardioversion of AF would allow restoration of regular rhythm at any place and time, which may improve the prognosis and quality of life of patients suffering from AF. We hope that our paper will contribute to the realization of this much desired option in clinical practice,” said corresponding author Daniël A. Pijnappels, PhD, of Leiden University Medical Center, in The Netherlands.

Source: Wiley

Categories : Cardiovascular Disease Obstetrics & GynaecologyTags :

Preterm Birth and Size Linked to Adult Fibrillation Risk

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A new study published in JAMA Pediatrics showed an association between being born preterm or large for gestational age and increased risks of atrial fibrillation later in life. Being small for gestational age at birth was only associated with an increased risk of atrial fibrillation up to the age of 18.

The incidence of atrial fibrillation in the young has increased over the past few decades, from low levels.

To date there have been little or mixed findings regarding the risk of atrial fibrillation in those with adverse birth outcomes. Atrial fibrillation increases the risk of stroke and other cardiovascular conditions, and is the most common form of cardiac arrhythmia. It mainly affects the middle-aged and the elderly. The estimated incidence in the young is low, 0.12 to 0.16%.

Low incidence in the young

A collaborative study involving researchers from Karolinska Institutet has now investigated the risk of atrial fibrillation according to preterm birth and foetal growth.

“Atrial fibrillation at a young age may involve a heavy socioeconomic burden for the affected individuals and we need to learn more about the underlying causes of the disease,” says first author Fen Yang, doctoral student at Karolinska Institutet. “Our findings may highlight the need to monitor and prevent the disease in individuals with an elevated risk of atrial fibrillation.”

“We found that individuals born preterm and those who were large for gestational age at birth had a slightly higher risk of developing atrial fibrillation up to middle-age than those with corresponding normal birth outcomes,” says principal investigator Krisztina László, associate professor at the Department of Global Public Health, Karolinska Institutet, and senior lecturer at the Department of Public Health and Caring Sciences at Uppsala University. “Individuals who were small for gestational age at birth had an increased risk of atrial fibrillation up to the age of 18, but not later in adulthood.”

The risk increase was 30% for individuals born preterm, 55% for individuals who were large at birth and 71% for individuals who were both preterm and large for gestational age at birth.

Eight million participants

The results of the study are based on statistical analyses of over eight million births from Danish (1978–2016), Finnish (1987–2014) and Swedish (1973–2014) medical birth registries who were followed for incident atrial fibrillation in the national patient and cause of death registries up to 2021. The results were compared with siblings in the same families. Since the study was observational, no causal relationships could be ascertained.

The researchers say that future studies may investigate the association between preterm birth, foetal growth, and the risk of atrial fibrillation up to old age.

Source: Karolinska Institutet

Categories : Cardiovascular Disease Neurodegenerative DiseasesTags :

Atrial Fibrillation Linked to Dementia Risk

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Source: American Heart Association

A large representative study found that individuals with newly diagnosed atrial fibrillation had a modestly elevated risk of developing dementia. The Journal of the American Heart Association study found that this risk was higher in younger adults and those without chronic kidney disease, but did not substantially vary across sex, race, or ethnicity.

In this study of nearly 200 000 adults, incidence rates for dementia over a median follow-up of 3.3 years were 2.79 versus 2.04 per 100 person-years in individuals with versus without atrial fibrillation, respectively. (This means that over one year, there would be an average of 2.79 dementia diagnoses among 100 people with atrial fibrillation and 2.04 diagnoses among 100 people without atrial fibrillation. This translates to 279 per 10 000 and 204 per 10 000.)

After adjustments, atrial fibrillation was associated with a 13% higher risk of dementia. Adults aged <65 years had a 65% higher risk compared with older adults, those without chronic kidney disease had a 14% higher risk than those with chronic kidney disease.

“These data highlight a possible link between atrial fibrillation and risk of subsequent dementia in certain populations. Further studies are needed to understand the mechanisms to explain this association, which may inform the use of treatments for atrial fibrillation,” said corresponding author Nisha Bansal, MD, MAS, of the University of Washington School of Medicine.

Source: Wiley

Categories : Cardiovascular Disease Substance UseTags :

Marijuana and other Substances Linked to Atrial Fibrillation

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A new longitudinal study of more than 23 million people in the US concludes that some commonly used and abused drugs pose previously unidentified risks for the development of atrial fibrillation (AF). The results appeared in the European Heart Journal.

The researchers analysed data from diagnostic codes from every hospital admission, emergency room visit and medical procedure in California for the years 2005 through 2015, identifying nearly one million people without preexisting AF, but who later developed AF during these years.

They found 132 834 patients used cannabis, 98 271 used methamphetamine, 48 700 used cocaine, and 10 032 used opiates. In the study, the researchers found that marijuana users had a 35% increased likelihood of later developing AF.

“Despite exhibiting a weaker association with incident AF than the other substances, cannabis use still exhibited an association of similar or greater magnitude to risk factors like dyslipidaemia, diabetes mellitus, and chronic kidney disease. Furthermore, those with cannabis use exhibited similar relative risk of incident AF as those with traditional tobacco use,” the study authors reported.

“To my knowledge, this is the first study to look at marijuana use as a predictor of future atrial fibrillation risk,” said principal investigator Gregory Marcus, MD, MAS, a UCSF professor of Medicine with the Division of Cardiology.

AF is an abnormally disordered pumping rhythm arising from electrical disturbances in the atria. In severe cases of faulty atrial pumping, clots may form in the atria, and then break off into the bloodstream and cause deadly strokes. AF-related strokes cause more than 150 000 US deaths each year.

Unlike cocaine or methamphetamine use, both stimulants previously known to sometimes lead to sudden cardiac death due to profound disruptions in the orderly electrical signalling and pumping within ventricles there is no demonstrated mechanism whereby marijuana use causes heart arrhythmias.

Source: University of California San Francisco

Categories : Cardiovascular DiseaseTags :

With Warfarin, Dropping Aspirin Reduces Bleeding Complications for Some

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Red blood cells
Source: Pixabay

Research from Michigan Medicine suggests that, for venous thromboembolism (VTE) or atrial fibrillation (AF) patients without a history of heart disease who are taking warfarin, stopping aspirin use causes their risk of bleeding complications to drop significantly.

For the study, which is published in JAMA Network Open, researchers analysed over 6700 people treated at anticoagulation clinics across Michigan for VTE as well as AF. Patients were treated with warfarin but also took aspirin despite not having history of heart disease.

“We know that aspirin is not a panacea drug as it was once thought to be and can in fact lead to more bleeding events in some of these patients, so we worked with the clinics to reduce aspirin use among patients for whom it might not be necessary,” said senior study author and cardiologist Geoffrey Barnes, MD.

Over the course of the study, aspirin use among patients fell by 46.6%. With aspirin used less commonly, the risk of a bleeding complication dropped by 32.3% – equivalent to preventing one major bleeding event per every 1000 patients who stop taking aspirin.

“When we started this study, there was already an effort by doctors to reduce aspirin use, and our findings show that accelerating that reduction prevents serious bleeding complications which, in turn, can be lifesaving for patients,” said Dr Barnes. “It’s really important for physicians and health systems to be more cognisant about when patients on a blood thinner should and should not be using aspirin.”

Several studies had found concerning links between concurrent use of aspirin and different blood thinners, which prompted this aspirin de-escalation.

One study reported that patients taking warfarin and aspirin for AF and VTE experienced more major bleeding events and had more ER visits for bleeding than those taking warfarin alone. Similar results were seen for patients taking aspirin and direct oral anticoagulants – who were found more likely to have a bleeding event but not less likely to have a blood clot.

“While aspirin is an incredibly important medicine, it has a less widely used role than it did a decade ago,” Dr Barnes said. “But with each study, we are seeing that there are far fewer cases in which patients who are already on an anticoagulant are seeing benefit by adding aspirin on top of that treatment. The blood thinner they are taking is already providing some protection from clots forming.”

For some people, aspirin can be lifesaving. Many patients who have a history of ischaemic stroke, heart attack or a stent placed in the heart to improve blood flow — as well as those with a history of cardiovascular disease — benefit from the medication.

The challenge comes when some people take aspirin without a history of cardiovascular disease and are also prescribed an anticoagulant, said first author Jordan Schaefer, MD.

“Many of these people were likely taking aspirin for primary prevention of heart attack or stroke, which we now know is less effective than once believed, and no one took them off of it when they started warfarin,” Dr Schaefer said. “These findings show how important it is to only take aspirin under the direction of your doctor and not to start taking over-the-counter medicines like aspirin until you review with your care team if the expected benefit outweighs the risk.”

Source: Michigan Medicine – University of Michigan

Categories : Cardiovascular Disease Surgeries & ProceduresTags :

Post-operative AF Linked to Risk of Hospitalisation for Heart Failure

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Associations between post-operative atrial fibrillation and incident heart failure hospitalisations. Credit: European Heart Journal

A study of over three million patients found that people who develop an atrial fibrillation (AF) after undergoing surgery have an increased risk of subsequent hospitalisation for heart failure.

The study, which is published in the European Heart Journal, showed that the risk of hospitalisation for heart failure among patients who developed AF after surgery increased regardless of whether or not the surgery was for a heart condition.

Among 76 536 patients who underwent heart surgery, 18.8% developed post-operative AF and the risk of hospitalisation for heart failure increased by a third compared to patients who did not develop AF. Among 2 929 854 patients without a history of heart disease who had surgery for non-heart-related conditions, 0.8% developed AF and the risk of hospitalisation for heart failure doubled.

The study’s first author, Dr Parag Goyal, Associate Professor of Medicine at Weill Cornell Medicine, said: “Our study, which to our knowledge is the largest study to date, shows that post-operative atrial fibrillation is associated with future heart failure hospitalisations. This could mean that atrial fibrillation is an important indicator of underlying but not yet detected heart failure; or it could mean that atrial fibrillation itself contributes to the future development of heart failure. While this study could not specifically address which of these mechanisms are at play, our hope is that this study will inspire future work into exploring the underlying mechanism seen in our important findings.

“Regardless of the mechanism, our study shows that post-operative atrial fibrillation is clearly an important entity that merits attention and incorporation into decision making. Most importantly, patients and doctors need to be more vigilant about heart failure symptoms among patients who develop post-operative atrial fibrillation. Those who do develop the condition may require more aggressive treatments for other risk factors for heart failure, such as high blood pressure, diabetes and narrowing of the arteries.”

Post-operative AF occurs in up to 40% of patients undergoing heart surgery and 2% of patients undergoing non-cardiac surgery. Doctors have tended to view it as a benign event, triggered by the stress of the surgery – but evidence is emerging that post-operative AF is linked to longer term problems such as stroke and death from any cause. Until now, there has been limited evidence regarding its association with subsequent heart failure.

For the current, retrospective study, the researchers collected data on hospital health claims from 2016 to 2018, adjusting for factors that could affect the results such as age, sex, race, insurance status, medical history and body mass index.

Study limitations include its observational nature which can only establish association, not causation. The study relies on administrative claims data and medical codes to identify medical conditions; it lacks more detailed information like management strategies for post-operative AF, and on the function and size of the left ventricle, which could affect the likelihood of developing AF.

The researchers hope to conduct further studies to understand the underlying mechanism and to investigate ways of preventing future hospitalisations for heart failure among patients who develop post-operative AF.

The researchers wrote in the conclusion that “In the meantime, clinicians should be aware that POAF [post-operative AF] may be a harbinger of HF.”

In an accompanying editorial, Dr Melissa Middeldorp and Professor Christine Albert, both from the Smidt Heart Institute at Cedars-Sinai, California, USA, write: “These data add to a growing body of literature suggesting that POAF is not just a transient response to surgery but may be reflective of underlying atrial and myocardial structural changes that not only predispose to the acute AF event but to other potentially related adverse cardiovascular events, such as HF hospitalisation.”

They write that further studies are needed for a better understanding of the mechanisms involved in placing people at greater risk of AF and post-operative heart failure is needed in order to reduce hospitalisation and deaths after surgery.

“With a greater understanding of patients’ full risk factor profile, we may advocate for early aggressive intervention at the initial manifestation of POAF, to improve outcomes and reduce rehospitalisation following cardiac and non-cardiac surgery,” they concluded.

Source: European Society of Cardiology