Tag: atrial fibrillation

With Warfarin, Dropping Aspirin Reduces Bleeding Complications for Some

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

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

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

Alcohol Triggers AF – But Not Caffeine or Other Likely Culprits

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Researchers have found that, out of possible triggers they tested, only alcohol use was consistently associated with more episodes of atrial fibrillation (AF). The study, published in JAMA Cardiologydid not find that the other triggers, caffeine, sleep deprivation and sleeping on the left side, to be associated with the common heart condition.

A surprising finding was that, although most of the things that participants thought to be related to their AF were not, those in the intervention group still had less arrhythmia than the people in a non self-monitoring control group.

“This suggests that those personalised assessments revealed actionable results,” said lead author Gregory Marcus, MD, MAS, professor at University of California, San Francisco. “Although caffeine was the most commonly selected trigger for testing, we found no evidence of a near-term relationship between caffeine consumption and atrial fibrillation. In contrast, alcohol consumption most consistently exhibited heightened risks of atrial fibrillation.”

Although caffeine was the most commonly selected trigger for testing, we found no evidence of a near-term relationship between caffeine consumption and atrial fibrillation.

In a brainstorming session, patients had said researching individual triggers for AF was their top priority, giving rise to the I-STOP-AFib study, which enabled individuals to test any presumed AF trigger. About 450 people participated, 58% male and 92% white.

Participants used a mobile electrocardiogram recording device along with a phone app to log potential triggers like drinking alcohol and caffeine, sleeping on the left side or not getting enough sleep, eating a large meal, a cold drink, or sticking to a particular diet, engaging in exercise, or anything else they thought was relevant to their AF. While participants were most likely to select caffeine as a trigger, there was no association with AF. Recent research has similarly failed to show a link between caffeine and arrhythmias – on the contrary, investigators found it may have a protective effect.

The new study demonstrated that consumption of alcohol was the only trigger that consistently resulted in significantly more self-reported AF episodes.

The individualised ‘n-of-1’ testing method did not validate participant-selected triggers for AF. But trial participants did report fewer AF episodes than those in the control group, and the data suggest that behaviours like avoiding alcohol could lessen the chances of having an AF episode.
“This completely remote, siteless, mobile-app based study will hopefully pave the way for many investigators and patients to conduct similar personalised ‘n-of-1’ experiments that can provide clinically relevant information specific to the individual,” said Prof Marcus.

Source: University of California, San Francisco

A Glass of Wine Raises Atrial Fibrillation Risk

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A single glass of wine can rapidly increase the risk of atrial fibrillation, according to new research published in Annals of Internal Medicine.

The study provides the first evidence that alcohol consumption significantly increases the chance of the heart rhythm condition occurring within a few hours, and is contrary to the notion of a cardioprotective effect of alcohol.

“Contrary to a common belief that atrial fibrillation is associated with heavy alcohol consumption, it appears that even one alcohol drink may be enough to increase the risk,” said Gregory Marcus, MD, MAS, professor of medicine in the Division of Cardiology at UCSF.

“Our results show that the occurrence of atrial fibrillation might be neither random nor unpredictable,” he said. “Instead, there may be identifiable and modifiable ways of preventing an acute heart arrhythmia episode.”

Atrial fibrillation (AF) is the most common heart arrhythmia seen clinically, but until now research has largely focused on risk factors and treatments for the disease, rather than what can trigger episodes. Large studies have established that chronic alcohol consumption can be a predictor for AF, and Marcus and other scientists have demonstrated that it is linked to increased risk for a first diagnosis of atrial arrhythmias.  

The research centered on 100 patients with documented AF who consumed at least one alcoholic drink a month, but without substance use disorders, certain allergies, or changing medications.

Each participant wore an electrocardiogram (ECG) monitor for roughly four weeks, pressing a button whenever they had a standard-size alcoholic drink. They were also all fitted with a continuously recording alcohol sensor. Blood tests reflecting alcohol consumption over the previous weeks were periodically administered. Participants consumed a median of one drink per day throughout the study period.

Researchers found that an AF episode was associated with two-fold higher odds with one alcoholic drink, and three-fold higher odds with two or more drinks within the preceding four hours. Increased blood alcohol concentration was also associated with AF episodes.

Study limitations included patients possibly forgetting to press their monitor buttons or minimising the number of button presses due to embarrassment, although these considerations would not have affected alcohol sensor readings. The study was also limited to those with established AF, not to the general population.

“The effects seem to be fairly linear: the more alcohol consumed, the higher the risk of an acute AF event,” said Prof Marcus. “These observations mirror what has been reported by patients for decades, but this is the first objective, measurable evidence that a modifiable exposure may acutely influence the chance that an AF episode will occur.”

Source: University of California – San Francisco

Screening for AF in the Elderly Using Thumb ECGs Reduces Stroke Risk

Screening for atrial fibrillation in 75- and 76-year-olds using thumb ECGS could reduce the risk of stroke, severe bleeding and death, according to a large-scale Swedish study.

Atrial fibrillation (AF) is associated with a five-fold increased risk of stroke, and the symptoms are often deleterious since large blood clots can form in the heart, breaking free and posing a stroke risk. Still, countries do not screen the general population for atrial fibrillation, but rather treat those patients who are discovered during routine care. This study by the Karolinska Institutet in Sweden and published in The Lancet, investigated the effectiveness of screening for AF.

“There has never really been a study that examines if it would be beneficial to screen for atrial fibrillation, which is why we wanted to investigate it,” said Emma Svennberg, cardiologist at the Karolinska University Hospital, Huddinge, and researcher at the Department of Medicine, Huddinge, Karolinska Institutet.

The study included almost 28 000 participants aged 75 or 76, randomised to be invited either to screening or to a control group, who received standard care. Of those invited to screening, more than half choose to participate. They completed a health questionnaire and performed a so-called thumb ECG (electrocardiogram), which involves placing one’s thumbs on an ECG device that measures the heart’s electrical activity.

Those without atrial fibrillation were asked to record their heart rhythm twice daily for two weeks using the ECG device which they took home. If the device registered irregular heart rhythms, the participants were referred to a cardiologist for a standardised work-up and, if there were no contra-indications, initiation of oral anticoagulant therapy.

The study’s 28 000 participants were then followed for at least five years. More detections of atrial fibrillation were recorded in the screening group, which also had a slightly lower incidence of death, stroke and severe bleeding than the control group.

“In total, 31.9 percent of those in the screening group experienced a negative event compared to 33 percent in the control group,” said Johan Engdahl, adjunct lecturer at the Department of Clinical Sciences, Danderyds Hospital, at Karolinska Institutet. “Now, that may sound like a small difference, but you must bear in mind that only about half of those invited to screening participated and it’s possible we would have seen a more pronounced difference had more people turned up for screening. Those who participated in the screening had significantly fewer negative events.”

Based on the findings, the researchers estimated that at least 2300 cases of stroke or death could be avoided per year in Sweden if a national screening of atrial fibrillation in the elderly was introduced.

Source: Karolinska Institute