Atrial fibrillation (or A-fib) is a type of cardiac arrhythmia, and experts say it is one of the most difficult types of cardiac problems to treat. It occurs when the top most chambers or atria of the heart “quiver” or fibrillate instead of pumping in the coordinated contraction found in a normal heartbeat. Episodes of A-fib can last for minutes, days, week, or they can be constant and persist for years. Some people have no symptoms when they suffer these arrhythmias, while others will experience such things as fainting, chest pain, or heart palpitations. The risk of developing A-fib increases with age, and statistics suggest about 8 percent of people over the age of 80 have this condition.
A-fib carries the risk of several different types of complications. It can cause blood to pool in the atria, forming clots that can then travel through the bloodstream and damage the brain, lungs, or other parts of the body. This is why people with A-fib have a significantly higher risk of suffering a stroke. A-fib also increases people’s risk of congestive heart failure.
Doctors have traditionally prescribed several different medications to people with A-fib, many of them designed to reduce the risks associated with symptoms of the condition. For example, anticoagulant drugs such as Coumadin (warfarin) are often given to patients to reduce their risk of blood clots. Others are given beta blockers or calcium-channel blockers to slow their heart rate, while other cardiologists concentrate their treatments on restoring a normal heartbeat with drugs like Cordarone (amiodarone), though these medications do not reduce patients’ risk of stroke. Some drugs that restore normal heartbeat, including Cordarone, can have potentially serious side effects such as pulmonary fibrosis (a type of scarring in the lungs), while some patients’ arrhythmias are actually made worse by these drugs.
The difficulty and complexity of treating A-fib– along with the prevalence of the disease – led the National Academy of Sciences’ Institute of Medicine to list A-fib as a priority for federal funding to assess which treatments are most effective at treating the condition. This is good timing, since two new treatments – one a medication and one a surgical intervention – have recently been approved to treat A-fib.
The medication, called Multaq (dronedarone), was approved by the U.S. Food and Drug Administration (FDA) in June 2009 for the treatment of A-fib and atrial flutter in patients whose hearts had returned to a normal rhythm or who were about to undergo electric-shock treatment to restore a normal heartbeat. The drug does, however, carry a “black box” warning for its link to serious complications – including death – in patients with severe heart failure. Because of the risk of side effects, the European Medicines Agency (the FDA’s European counterpart) has recommended that Multaq only be used in patients who have exhausted all other treatment options to ease their A-fib.
The surgical intervention, called radiofrequency catheter ablation, involves the use of special wires or catheters that are threaded into the heart via the groin or neck. These wires deliver a low-voltage, high-frequency electrical current to the areas of the heart that are not contracting properly. This permanently damages these tissues’ ability to conduct their abnormal electrical impulses, thus stopping the arrhythmia and curing the patient of A-fib.
The potential negative side effects of the drugs currently used to treat A-fib – including Multaq – are causing many patients to seek surgical intervention with radiofrequency catheter ablation, despite the fact that it’s only been tried on a few patients thus far.
Given the development of these new treatment options and the questions about their effectiveness, the Institute of Medicine’s priority federal funding for comparisons of treatment options for A-fib couldn’t have come at better time. This opportunity could have a profound impact on the treatment options – and prognosis – for the many people who live with A-fib.
Sources: U.S. Food and Drug Administration; Institute of Medicine; UptoDate.com; American Heart Association; Wall Street Journal; StopAfib.org; DailyMarkets.com