Should You Get Pills or Surgery for Atrial Fibrillation?

Many older Americans have the worrisome and potentially dangerous irregular heartbeat known as atrial fibrillation, or “a-fib,” and they’re typically offered medicines or a surgery called ablation to correct it.

Which works best?

Two new trials may have the answer. Researchers say ablation and medicines perform similarly in protecting a-fib patients from stroke, death and other complications.

However, ablation may beat out drug therapy over the long term, reducing recurrences of a-fib and related hospitalizations for years to come, researchers say.

Patients who got ablation — where a catheter is used to tweak the heart muscle cells responsible for the arrhythmia — also seemed to have less shortness of breath, less fatigue and all-around better quality of life five years later, compared to those who got drug therapy alone.

The quality-of-life trial, “because of its size and duration, provides extraordinary new data regarding the patient’s perspective,” said Dr. Yves Rosenberg.

He was program officer for the study, and is also chief of the Atherothrombosis and Coronary Artery Disease Branch at the U.S. National Heart, Lung, and Blood Institute (NHLBI), which helped fund both trials.

A cardiologist who reviewed the findings said the data should reassure patients.

“I think the takeaway from this study is that catheter ablation is effective and safe for treating atrial fibrillation,” said Dr. Laurence Epstein, who directs electrophysiology at Northwell Health in Manhasset, N.Y.

“If you have atrial fibrillation and are symptomatic, ablation is a reasonable first-line option, as opposed to taking drugs,” he said.

Treatment pros and cons

According to the NHLBI, a-fib affects at least 2.7 million Americans and can lead to stroke, heart failure, and even mental impairment. Symptoms include rapid heart palpitations (“flip-flops” or skips); fatigue; shortness of breath, and difficulty doing physical activity.

“Since current drug therapies often have limited effectiveness in controlling atrial fibrillation, it is very important to understand whether ablation, an invasive procedure, yields better outcomes,” Dr. David Goff, director in the division of cardiovascular sciences at the NHLBI, said in an institute news release.

As Epstein explained, during ablation, “long catheters — wires with electrodes on them — are placed into the heart via the large veins in the groin. Radio waves are delivered from the catheter to the heart muscle, which causes heat and the controlled destruction of the muscle cells responsible for causing atrial fibrillation.”

Sometimes ablation is performed using tiny balloons that freeze the heart muscle to create the same effect.

Of course, no treatment is foolproof. “Depending on the patient the procedure can be as effective as 80-90 percent,” Epstein said, “but in others, at best, 50 percent.”

Many other patients get drug therapy alone to control the aberrant heart rhythm. But Epstein said outcomes are often “disappointing because the drugs do not work that well and that they can cause ‘pro-arrhythmia.’

“Pro-arrhythmia is when a drug used to treat an abnormal heart rhythm can actually cause a worse, more dangerous heart rhythm,” he explained.

Long-term benefits

To settle the meds-versus-ablation debate, the NHLBI helped conduct these two trials, which included more than 2,200 patients treated at 126 sites in the United States, Canada, Asia and Europe.

Half the patients had ablation and half were put on drug therapy, but could have ablation if their a-fib symptoms could not be controlled with medication — something known as “intent to treat.”

In the end, about 27 percent of the patients who started on drug therapy did end up undergoing ablation.

The median follow-up of patients in the trial was about four years.

“While data from the trial did not show that ablation was superior to drug therapy in reducing rates of deaths and strokes, it showed reduced recurrence of atrial fibrillation, as well as reductions in hospitalizations,” Rosenberg said in the news release.

The researchers noted that the overall rate of deaths and strokes was lower than expected. Also, about 9 percent of the patients assigned to receive ablation did not, in the end, undergo the procedure.

So, “when we examined the data according to the treatment actually received, the ablation group had significantly lower rates of death as well as the combination of death, disabling stroke, serious bleeding, or cardiac arrest compared with patients who only received drug therapy,” said study principal investigator Dr. Douglas Packer. He’s a cardiologist and professor of medicine at Mayo Clinic in Rochester, Minn.

The research team found that 12 months after the start of treatment, both groups of patients had at least some improvement in their quality of life. However, those in the ablation group had a larger decline in symptoms such as fatigue and shortness of breath, and their boost in quality of life lasted through five years of follow-up.

At the start of the study, 86 percent of patients in the ablation group and 84 percent on drug therapy reported atrial fibrillation symptoms during the previous month. By the end of the study, only 25 percent of patients in the ablation arm and 35 percent of those on drugs only reported symptoms.

Patients with the most severe symptoms at the start of the study had much greater improvement after ablation than those who initially had mild symptoms, the researchers added.

Dr. Satjit Bhusri is a cardiologist at Lenox Hill Hospital in New York City. Reviewing the new data, he said that the trials give doctors and patients valuable guidance.

First of all, he said, if your a-fib isn’t so bad that it harms your quality of life, perhaps controlling it with medicines alone might work. However, when quality of life is affected, a move to ablation therapy may be warranted, Bhusri said.

For his part, Epstein believes “we certainly need to continue to study these findings. As technology continues to advance, and ablation procedures become safer and more effective, ablation will most certainly become the treatment of choice.”

The papers were published in the Journal of the American Medical Association.

Source : HealthDay

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Low-Carb Diet Tied to Common Heart Rhythm Disorder

Low-carb diets are all the rage, but can cutting carbohydrates spell trouble for your heart? People getting a low proportion of their daily calories from carbohydrates such as grains, fruits and starchy vegetables are significantly more likely to develop atrial fibrillation (AFib), the most common heart rhythm disorder, according to a study being presented at the American College of Cardiology’s 68th Annual Scientific Session.

The study, which analyzed the health records of nearly 14,000 people spanning more than two decades, is the first and largest to assess the relationship between carbohydrate intake and AFib. With AFib, a type of arrhythmia, the heart doesn’t always beat or keep pace the way it should, which can lead to palpitations, dizziness and fatigue. People with AFib are five times more likely to have a stroke than people without the condition. It can also lead to heart failure.

Restricting carbohydrates has become a popular weight loss strategy in recent years. While there are many different low-carbohydrate diets including the ketogenic, paleo and Atkins diets, most emphasize proteins while limiting intake of sugars, grains, legumes, fruits and starchy vegetables.

“The long-term effect of carbohydrate restriction is still controversial, especially with regard to its influence on cardiovascular disease,” said Xiaodong Zhuang, MD, PhD, a cardiologist at the hospital affiliated with Sun Yat-Sen University in Guangzhou, China, and the study’s lead author. “Considering the potential influence on arrhythmia, our study suggests this popular weight control method should be recommended cautiously.”

The findings complement previous studies, several of which have associated both low-carbohydrate and high-carbohydrate diets with an increased risk of death. However, while previous studies suggested the nature of the non-carbohydrate component of the diet influenced the overall pattern observed, the new study did not.

“Low carbohydrate diets were associated with increased risk of incident AFib regardless of the type of protein or fat used to replace the carbohydrate,” Zhuang said.

Researchers drew data from Atherosclerosis Risk in Communities (ARIC), a study overseen by the National Institutes of Health that ran from 1985-2016. Of the nearly 14,000 people who did not have AFib when they enrolled in the study, researchers identified nearly 1,900 participants who were subsequently diagnosed with AFib during an average of 22 years of follow-up.

Study participants were asked to report their daily intake of 66 different food items in a questionnaire. The researchers used this information along with the Harvard Nutrient Database to estimate each participant’s daily carbohydrate intake and the proportion of daily calories that came from carbohydrates. On average, carbohydrates comprised about half of calories consumed. The Dietary Guidelines for Americans recommend that carbohydrates make up 45 to 65 percent of total daily calorie intake.

Researchers then divided participants into three groups representing low, moderate and high carbohydrate intake, reflecting diets in which carbohydrates comprised less than 44.8 percent of daily calories, 44.8 to 52.4 percent of calories, and more than 52.4 percent of calories, respectively.

Participants reporting low carbohydrate intake were the most likely to develop AFib. These participants were 18 percent more likely to develop AFib than those with moderate carbohydrate intake and 16 percent more likely to develop AFib than those with high carbohydrate intake.

Several potential mechanisms could explain why restricting carbohydrates might lead to AFib, Zhuang said. One is that people eating a low-carbohydrate diet tend to eat fewer vegetables, fruits and grains—foods that are known to reduce inflammation. Without these foods people may experience more inflammation, which has been linked with AFib. Another possible explanation is that eating more protein and fat in lieu of carbohydrate-rich foods may lead to oxidative stress, which has also been associated with AFib. Finally, the effect could be related to an increased risk of other forms of cardiovascular disease.

Zhuang said that while the research shows an association, it cannot prove cause and effect. A randomized controlled trial would be needed to confirm the relationship between carbohydrate intake and AFib and assess the effect in a more ethnically diverse population. In addition, the study did not track participants with asymptomatic AFib or those who had AFib but were never admitted to a hospital, nor did it investigate different subtypes of AFib, so it is unknown whether patients were more likely to have occasional episodes of arrhythmia or persistent AFib. The study did not account for any changes in diet that participants may have experienced after completing the questionnaire.

Source: American College of Cardiology

Updated Treatment Guidelines for Irregular Heartbeat Atrial Fibrillation

A newer type of blood-thinning medications, non-vitamin K oral anticoagulants (NOACs), is now recommended as the preferred alternative to warfarin for reducing the risk of stroke associated with atrial fibrillation (AFib), according to a focused update to the 2014 American Heart Association/American College of Cardiology/Heart Rhythm Society Guideline for the Management of Patients With Atrial Fibrillation.

AFib is a type of irregular heartbeat in the atria, or upper chambers of the heart. Because the heart beat is irregular, blood can pool and then clot inside the atria, particularly in the left atrial appendage, a pouch that is part of the anatomy of the upper left chamber of the heart. If the clots formed within the left atrium migrate within the blood and reach the brain, a stroke caused by a blocked artery can occur even in people with no obvious symptoms of AFib.

Blood-thinning medications called anticoagulants have long been recommended to reduce the risk of stroke in patients with AFib who have an increased risk of thromboembolism (blockage of a blood vessel by a clot travelling in the bloodstream) and/or stroke caused by narrowed or blocked arteries

To reduce stroke risk in appropriate AFib patients, a newer class of anticoagulants known as NOACs is now the preferred recommended drug class over the traditional medication warfarin, unless patients have moderate to severe mitral stenosis (narrowing of the mitral valve) or have an artificial heart valve. NOACs include dabigatran, rivaroxaban, apixaban and edoxaban.

“Patients with AFib are at increased risk of stroke, which can be devastating. A goal of treating AFib patients is to make blood less likely to form clots, which reduces the risk of stroke. New scientific studies show that NOACs may be safer for patients because there is less risk of bleeding, and they may also be more effective at preventing blood clots than warfarin,” said Craig T. January, M.D., Ph.D., co-chair of the focused update published simultaneously in the American Heart Association journal Circulation, Journal of the American College of Cardiology and the Heart Rhythm Society journal, HeartRhythm.

Guidelines rank recommendations as strong, weak, or harmful on the basis of the quality and quantity of the scientific research that supports each recommendation. Recommendations with the highest level of evidence have more than one randomized controlled trial reporting similar results, whereas the lowest-ranked recommendations are based on the clinical experience of experts. Along with the strong recommendation to use NOACs in favor of warfarin for many patients, the new guidelines recommend:

  • Weight loss for overweight or obese patients. Studies find that losing weight can reduce the health risks associated with or even reverse AFib. It can also lower blood pressure (high blood pressure is often associated with AFib).
  • New drugs are available to reverse the effect of NOACs (called reversal agents). These reversal agents, while used infrequently, are helpful when there are signs of severe bleeding caused by a NOAC or when a patient on a NOAC needs an emergency surgical procedure.

“AFib patients should talk to their healthcare provider about any concerns they have about their prescribed medications and whether or not losing weight would benefit their health,” said January, who is professor of cardiovascular medicine at the University of Wisconsin in Madison, Wisconsin.

The new guidelines also suggest that NOACs could even be used in people at lower risk of stroke than previously thought. Although the evidence for this recommendation is not yet definitive, emerging research is beginning to suggest that the benefit of NOACs for reducing stroke risk outweighs the risk of taking them, said January.

Source : American Heart Association


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Catheter Ablation Superior to Standard Drug Therapy for Atrial Fibrillation

A meta-analysis of randomized controlled trials found that catheter ablation was superior to conventional drug therapy alone for patients with atrial fibrillation and heart failure. Findings are published in Annals of Internal Medicine.

Atrial fibrillation is associated with thromboembolic stroke, systemic embolism, and decompensated heart failure. Catheter ablation is an established therapeutic strategy for atrial fibrillation, but guidelines recommend caution in certain patients. The benefits and harms of catheter ablation versus drug therapy for patients with atrial fibrillation have not been firmly established.

Researchers from Icahn School of Medicine at Mount Sinai reviewed six published randomized controlled trials to compare the benefits and harms between catheter ablation and standard drug therapy (rate or rhythm control medications) in adult patients with atrial fibrillation and heart failure. Their analysis showed that compared to medication, catheter ablation was associated with reductions in all-cause mortality and heart failure hospitalizations and improvements in left ventricular ejection fraction; quality of life; cardiopulmonary exercise capacity; and 6-minute walk test distance, with no statistically significant increase in serious adverse events.

The major adverse events rates observed in the pooled analysis were 7.2 percent in the ablation group and 3.8 percent in the standard therapy group. Despite the complications associated with catheter ablation, the authors explain that the long-term benefits in all-cause mortality, heart failure hospitalizations, and overall clinical outcomes must be weighed in clinical decision making.

Source: EurekAlert!


Read also at Medtronic:

WHAT IS CATHETER ABLATION? . . . . .


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Too Much Salt Might Help Spur Irregular Heartbeat

A high-salt diet could raise your risk for a common heart rhythm disorder, new research suggests.

Atrial fibrillation (A-fib) is a quivering or irregular heartbeat that can lead to blood clots or other complications. It affects millions of people worldwide and puts them at higher risk for stroke and, in rare cases, can lead to heart failure.

This study included 716 middle-aged men and women in Finland who were followed for an average of 19 years. During that time, 74 of the participants were diagnosed with atrial fibrillation.

Those with the highest levels of salt in their diet had a higher rate of atrial fibrillation than those with the lowest salt intake. After accounting for several other risk factors — including age, body fat, blood pressure and smoking — the researchers found that salt consumption was independently associated with the risk of atrial fibrillation.

But the study only found an association — it did not prove that a high-salt diet causes the heart rhythm disorder.

The study was published recently in the Annals of Medicine.

“This study provides the first evidence that dietary salt may increase the risk of new-onset atrial fibrillation, adding to a growing list of dangers from excessive salt consumption on our cardiovascular health,” said study author Tero Paakko, from the University of Oulu in Finland.

“Although further confirmatory studies are needed, our results suggest that people who are at an increased risk of atrial fibrillation may benefit from restricting salt in their diet,” Paakko said in a journal news release.

The chances of developing atrial fibrillation increase with age, and the condition affects about 7 in 100 people 65 and older.

“With estimates suggesting that over three-quarters of salt consumed is already added in processed foods, reducing salt intake at a population level could have a hugely beneficial impact on new-onset atrial fibrillation and overall cardiovascular disease,” Paakko said.

Source: HealthDay


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