American Heart Association Issues More Lenient Guidelines for Atrial Fibrillation
Patients with atrial fibrillation who fail to follow treatment guidelines risk shortening their lives, according to a recent report issued by the World Heart Federation. Most often with chronic conditions, lack of knowledge or difficulty with rigid guidelines is often to blame. The American Heart Association has found that taking a slightly more lenient approach for those with stable functioning of the heart’s ventricles may be just as beneficial as more rigid control.
AHA Issues New Recommendations for Medications and Procedures for AF
Atrial fibrillation is an irregular heart rhythm that occurs when the heart’s two upper chambers beat erratically, causing them to pump blood unevenly and inefficiently. This can cause blood to pool and clot in the chambers, increasing the risk of stroke or heart attack.
In response to new evidence from the evolving science, the American Heart Association in collaboration with the American College of Cardiology created a task force to perform a “focused update” on the existing recommendations for the treatment of atrial fibrillation which were issued in 2006. The committee reviewed and ranked the evidence which is presented in the January issue of the journal Circulation, published online this month.
Previously, the recommendation for the management of atrial fibrillation was to strictly control a patient’s heart rate at less than 80 beats per minute at rest and less than 110 during a six-minute walk. The American Heart Association has found that this strict control provides no advantage over a more lenient approach that achieves a resting heart rate of less than 110 in patients with persistent atrial fibrillation but who have a stable functioning of the heart’s two lower chambers or who present with no symptoms related to the arrhythmia.
"The evidence showed rigid control did not seem to benefit patients," said L. Samuel Wann, M.D., the chair of the task force and director of cardiology at the Wisconsin Heart Hospital in Milwaukee. "We don't need to be as compulsive about absolute numbers, particularly doing exercise tests and giving multiple drugs based solely on heart rate. Patients with symptoms due to rapid heart action need treatment, and the long term adverse effects of persistent tachycardia on ventricular function are still of concern."
Another new recommendation the task force has issued is that the addition of clopidogrel (brand name: Plavix) to aspirin to reduce the risk of having a major vascular event might be considered in certain patients with atrial fibrillation if they are not able to tolerate warfarin (brand name: Coumadin).
Dronedarone (brand name: Multaq) is another medication that could decrease the need for hospitalization for cardiovascular events for patients with a certain type of atrial fibrillation called paroxysmal AF. Also called lone atrial fibrillation (LAF), the erratic heart rate is not caused by an underlying heart problem. While most AF cases are caused by heart disease or an abnormality of the heart, about 12 to 30% are classified as paroxysmal.
Per the AHA, however, dronedarone should not be administered to patients with class four heart failure or in patients who have had an episode of decompensated heart failure in the past four weeks.
Catheter ablation is another type of treatment used to treat some types of arrhythmia. During the procedure, a long, thin flexible tube is guided to the heart through a blood vessel and radiofrequency is used to destroy small areas of heart tissue which may help to restore normal heart rate and rhythm. The AHA states that catheter ablation is reasonable to treat symptomatic persistent AF and symptomatic paroxysmal AF in certain patients.
"Catheter ablation is one of the most rapidly growing procedural areas in cardiology right now, and the evidence does support that," Wann said.
SOURCE: The American Heart Association, Circulation: Journal of the American Heart Association, the Journal of the American College of Cardiology, and HeartRhythm Journal, published online December 2010