February 19, 2014
News Review From Harvard Medical School -- Procedure, Drugs Compared for Rhythm Flaw
A procedure works better than medicines to treat a common heart rhythm problem, a small new study finds. But the side effects can be serious. Atrial fibrillation occurs when the heart's upper chambers beat in an erratic, fast rhythm. This can increase the risk of clots and stroke. The usual treatment is a medicine that returns the heart to a normal rhythm or a combination of medicines that can slow the heart and prevent clots. A newer option is called ablation. This procedure uses a heated probe to burn a small area of the heart. Burning blocks the erratic electrical signals that cause the rhythm problem. The new study included 127 people who had just been diagnosed with atrial fibrillation. They were randomly assigned to receive either a medicine to normalize the heart rhythm or ablation. In the next 2 years, 72% of the medicine group and 54% of the procedure group had episodes of atrial fibrillation that lasted at least 30 seconds. For many who got better, symptoms came back. Of those who got the procedure, 9% had a serious problem afterward. Four people had blood leak out of a hole in the heart. This is a life-threatening problem. The Journal of the American Medical Association published the study. HealthDay News wrote about it February 19.
By Reena L. Pande, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Atrial fibrillation is a common abnormal heart rhythm that is uneven (irregular) and fast. Doctors have long debated the best ways to treat it. A study that was just released compares the benefits of taking medicines or doing a procedure.
Atrial fibrillation occurs in as many as 3 million U.S. adults. Normally, the heartbeat starts in the top chambers (the atria). It sends a signal to the bottom part of the heart (the ventricles), which then squeeze and pump blood throughout the body. In normal situations, this happens between 60 and 100 times per minute.
In atrial fibrillation (also known as AF or AFib), the top part of the heart beats in an unusually fast and uncoordinated way. Only some of these signals reach the pumping chambers. The result is an irregular and often fast rhythm.
Atrial fibrillation poses two main problems:
- Symptoms -- People with AF can feel palpitations, lightheadedness, shortness of breath, chest discomfort and other symptoms. For unclear reasons, some people have no symptoms at all.
- Risk of stroke -- When the atria do not move in a coordinated fashion, blood flow is sluggish. This leads to a risk of blood clots forming in the heart. A clot that travels from the heart to the brain can block blood flow and cause a stroke. This risk is higher in older adults and those with congestive heart failure, high blood pressure, diabetes or blood vessel (vascular) disease. For some people, the risk of stroke can be lowered by use of blood thinners.
Treatment of atrial fibrillation is different for each person. However, this strategy can be a guide for all patients:
- The first step is to look for and treat any underlying cause. People develop AF for many reasons. Some of them include other heart problems, thyroid problems, lung disease, certain medicines, recent surgery and sleep apnea. But often no underlying cause can be determined.
- Next, we need to slow the heart rate. This can be done with medicines.
- Then we determine whether a blood thinner is appropriate. This depends on each person's risk of having a stroke, balanced with the risk of bleeding.
- The final step is to figure out whether any special procedures need to be performed to get the heart back into a normal rhythm.
When to use procedures is an area of some debate. Old studies have concluded that the important thing is to control the heart rate and limit the risk of stroke. In this case, the studies suggested, it doesn't much matter if the heart is in atrial fibrillation or restored to a normal rhythm.
However, a new study suggests that a procedure may be better than standard treatment with medicines alone. This procedure, called ablation, burns a part of the atria to zap the heart out of atrial fibrillation. This very small study suggested that people who had ablation were less likely to have a return of palpitations and other AF symptoms.
On the other hand, at the two-year mark, many of these patients had symptoms again. Another concern is safety. Medicines used to treat AF are generally quite safe and well tolerated. But ablation is not without risk. There's even the possibility of burning a hole in the heart.
What Changes Can I Make Now?
I would suggest starting by asking your doctor these questions:
- "I have atrial fibrillation. Is it OK to just use medicines, or do I need a procedure?" Despite the findings in this new small study, most doctors start with medicines. Given the risks of ablation, they move to the more invasive approach only if medicines are unsuccessful.
- "Should I be on a blood thinner?" A blood thinner can help many people if the bleeding risk is not too high. Older adults and others with increased risk of stroke may benefit. High blood pressure, diabetes and congestive heart failure are among the factors that increase risk. Remember, the goal is not to treat the atrial fibrillation itself, but rather to lower the risk of having a stroke.
- "Do I have to take warfarin (Coumadin)? Are there other options?" Several new blood thinners have become available in the last few years. They do not need to be monitored with regular blood tests. They also do not interact with food and other medicines, as warfarin does. Talk to your doctor about whether one of these medicines might be right for you.
What Can I Expect Looking to the Future?
Management of heart diseases is changing day by day. Newer and safer procedures are becoming available. For now, despite this small study, the best first approach in the management of atrial fibrillation remains control of the heart rate and use of a blood thinner if appropriate.
If this strategy does not work, doctors and patients can decide to move to more aggressive approaches, such as ablation. Future advances will likely continue to lower the risk of these procedures. And that may change our approach to treating this very common condition.