Dronedarone, Rate Control, and Catheter Ablation Incorporated in Updated AF Guidelines

A focused update on the guidelines for the management of atrial fibrillation has been released by the ACC, AHA, and HRS. Most notably, the new guidelines incorporate recent data from clinical trials evaluating dronedarone, clopidogrel, strict rate control, and catheter ablation. Here are the major highlights of the document:

  • Dronedarone can reduce CV hospitalizations related to AF but should not be given to patients with class IV heart failure or who have had a recent episode of decompensated heart failure.
  • Clopidogrel in addition to aspirin “might be considered” for stroke prevention in patients who can not take warfarin.
  • Strict rate control is no better than lenient rate control.
  • Catheter ablation gains a class 1 recommendation when performed in experienced centers for selected patients who have failed antiarrhythmic drug therapy and have normal or mildly dilated left atria, normal or mildly reduced LV function, and no severe pulmonary disease. Catheter ablation is also a reasonable option to treat sympatomatic persistent AF and sympatomatic paroxysmal AF in patients with significant  left atrial dilation or with significant LV dysfunction.

Sanjay Kaul, who has been critical of efforts to endorse widespread usage of dronedarone in the past, commented for CardioBrief:

The totality of the data suggests that although dronedarone has the ability to control both rhythm and rate in patients with atrial fibrillation or flutter, compared with the gold standard amiodarone, it is only half as effective in maintaining sinus rhythm, while not offering improved tolerability or safety advantage. Thus, if one were to accept that comparative effectiveness research has become a cornerstone of evidence-based medicine (and health care reform), it is hard to envision how dronedarone could be chosen over amiodarone for maintenance of sinus rhythm. It is doubly hard to conceive dronedarone as a first line option for the management of atrial fibrillation. Clearly, both the ACC/AHA/HRS and the ESC guideline writing committees have overstated the case for dronedarone for maintenance of sinus rhythm, and overlooked reports of its marginal efficacy and safety in the ‘real-world’ practice.

With regards to decreasing the need for hospitalization for cardiovascular events in patients with paroxysmal AF or after conversion of persistent AF, the Class IIa, level B guideline recommendation is appropriate and well supported by trial evidence. Although no other antiarrhythmic drug has been shown to reduce cardiovascular hospitalizations, it is entirely plausible that other class I or III antiarrhythmic drugs would have similar effects if systematically evaluated in this manner.”

Here is the press release from the AHA:

American Heart Association/American College of Cardiology/Heart Rhythm Society Guidelines:

Strict heart rate control provides no advantage over lenient approach

DALLAS, Dec. 20, 2010 — Strictly controlling the heart rate of patients with atrial fibrillation provides no advantage over more lenient heart rate control, experts report in a focused update of the 2006 guidelines for the management of patients with atrial fibrillation.

The new recommendations, published in Circulation: Journal of the American Heart Association, the Journal of the American College of Cardiology, and HeartRhythm Journal, are updates of the American College of Cardiology/American Heart Association/European Society of Cardiology 2006 Guidelines for the Management of Patients With Atrial Fibrillation. The 2010 focused update allows experts to swiftly incorporate significant new findings into the guidelines.

Atrial fibrillation is an irregular heart rhythm that occurs when the heart’s two upper chambers beat erratically, causing the chambers to pump blood rapidly, unevenly, and inefficiently. Blood can pool and clot in the chambers, increasing the risk of stroke or heart attack. More than 2 million Americans live with the condition.

The heart rate recommendation, one of several in the update, states that strict treatment to control a patient’s heart rate (at less than 80 beats per minute at rest and less than 110 during a six-minute walk) is not beneficial over a more lenient approach to achieve a resting heart rate of less than 110 in patients with persistent, or continuous, atrial fibrillation with stable functioning of the ventricles, (the heart’s lower chambers).

“The evidence showed rigid control did not seem to benefit patients,” said L. Samuel Wann, M.D., chair of the focused update writing group and director of cardiology at theWisconsin 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.”

The evidence-based updates, which reflect major advances in disease management, include:


A combination of aspirin and the oral antiplatelet drug clopidogrel “might be considered” to prevent stroke or other types of blood clots in atrial fibrillation patients who are poor candidates for the clot-preventing drug warfarin. Although warfarin remains effective, it requires patients to have regular testing to monitor its effectiveness and dosage adjustment. “It’s a minor inconvenience for most, but a major inconvenience for some,” Wann said.


New research showed dronedarone, which is administered as a pill, could reduce hospitalizations for cardiovascular events related to atrial fibrillation. Dronedarone should not be given to patients with NYHA class IV heart failure or patients who have had an episode of decompensated heart failure in the past 4 weeks, especially if they have depressed ventricular function.

Dronedarone is associated with less hospitalizations and less side effects than amiodarone.

Catheter Ablation

Several new or revised recommendations support the role of catheter ablation as a treatment to maintain normal heart rhythm. In catheter ablation, a tube is inserted into a blood vessel and guided to the heart, where radiofrequency energy is applied that can destroy small areas of tissue responsible for an arrhythmia.

Ablation is useful when performed for selected patients at experienced centers (in which more than 50 cases are performed annually). For those patients with symptomatic paroxysmal atrial fibrillation (comes and goes on its own), who have not had success with drug treatment, do not have severe lung disease, and have a normal or mildly dilated left atrium and normal or mildly reduced function of the left ventricle, catheter ablation “is useful in maintaining sinus rhythm.”

The treatment option is also reasonable for patients with symptomatic persistent atrial fibrillation, and it may be reasonable to treat symptomatic paroxysmal atrial fibrillation in patients with significant enlargement of the left atrium or with significant left ventricle dysfunction.

“Catheter ablation is one of the most rapidly growing procedural areas in cardiology right now, and the evidence does support that,” Wann said.

Co-authors are: Anne B. Curtis, M.D.; Kenneth A. Ellenbogen, M.D.; N.A. Mark Estes III, M.D.; Michael D. Ezekowitz, M.B., Ch.B.; Warren M. Jackman, M.D.; Craig T. January, M.D.; James E. Lowe, M.D.; Richard L. Page, M.D.; David J. Slotwiner, M.D.; William G. Stevenson, M.D.; and Cynthia M. Tracy, M.D. Author disclosures are on the manuscript.


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