BUFFALO, N.Y. -- Anne B. Curtis, MD, Charles and Mary Bauer
Professor and Chair of the University at Buffalo Department of
Medicine in the School of Medicine and Biomedical Sciences, is a
key contributor to the new guidelines for physicians, published
last month, that incorporate the latest research on the best way to
treat patients with atrial fibrillation.
Over the past decade, Curtis, one of the world's leading
clinical cardiac electrophysiologists and an expert in cardiac
arrhythmias, has played an important role in developing national
guidelines for treating atrial fibrillation.
The guidelines are issued by the American College of Cardiology
Foundation/American Heart Association Task Force on Practice
Guidelines. They provide health-care providers with recommendations
based on the most current research findings so that they can make
the best treatment decisions for their patients.
In the Q&A below, Curtis explains how the guidelines will
affect the way physicians treat patients with atrial
What is atrial fibrillation? Atrial fibrillation is a
heart rhythm disorder that is manifested as a rapid, irregular
heart beat that can cause symptoms such as fatigue, shortness of
breath, exercise intolerance, and even lead to heart failure in
some patients. It is the most common sustained type of irregular
heartbeat observed in hospital patients.
How is atrial fibrillation normally treated? Atrial
fibrillation is usually treated with medications to slow the heart
rate, anti-arrhythmic drugs to keep the rhythm normal and
anti-thrombotic drugs to prevent stroke. Anti-thrombotic drugs, or
drugs to prevent blood clots from forming, are used because the
fibrillating chambers of the heart can develop blood clots, which,
if they break off and go to the brain, can cause stroke. All these
efforts manage, but don't cure, the arrhythmia. When nonsurgical
treatment fails, atrial fibrillation can be treated with catheter
ablation; however ablation does not always prevent recurrences or
the need for additional procedures.
What was the purpose of the new guidelines, issued in
January? The purpose of the 2011 American ACCF/AHA/HRS Focused
Update on the Management of Patients with Atrial Fibrillation was
to update the guidelines issued in 2006, in light of new research
What is the most significant change in the new guidelines
that patients should be aware of? The most significant change
in the new guidelines has to do with catheter ablation, the
minimally invasive surgical procedure used to treat patients with
atrial fibrillation when they have not responded to medications. In
catheter ablation, a catheter is threaded into a patient's blood
vessels and into the heart, where energy is applied to create scar
tissue in defined areas to prevent abnormal electrical impulses
from causing atrial fibrillation. The new guidelines establish this
procedure as a class 1 recommendation for selected patients who
have failed medical therapy. That is a stronger recommendation than
it was in the 2006 guidelines, based on the fact that ablation is
now considered a standard, rather than an experimental, procedure.
This change is based on studies showing that ablation is effective
in preventing recurrences of atrial fibrillation better than
continued drug therapy.
What do you think was the most surprising change in the new
guidelines? The most surprising change to me is based on recent
research showing that strict control of the heart rate of patients
with atrial fibrillation doesn't seem to result in better outcomes
than more lenient control. This recommendation was based on a study
called RACE II, Rate Control Efficacy in Permanent Atrial
Fibrillation, which found no difference in outcomes between
patients who had strict control and those with more lenient
control. It should be recognized, however, that in long-term
follow-up, there was only a mean difference of nine beats per
minute between the two groups. I believe it is still a disadvantage
for patients to have very high heart rates in AF, say, over 120
beats-per-minute but, conversely, aggressively treating patients
until the heart rate gets too slow, for example, much below 60-70
beats-per-minute, has disadvantages, too. One consequence could be
that a patient might end up needing a pacemaker to prevent slow
What other changes in the guidelines may affect how patients
with AF are treated? A new anti-arrhythmic agent called
dronedarone is now being recommended to prevent hospitalizations in
patients with AF. In 2006, when the previous guidelines were
issued, this drug wasn't available yet.
What is the purpose of the additional update, issued this
week? The purpose of this week's update is to release a new
guideline recommendation for a recently released anticoagulant,
dabigatran. It is recommended as an alternative to warfarin for
prevention of stroke in patients with atrial fibrillation who do
not have serious valvular heart disease, an artificial heart valve
or serious kidney or liver disease.
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