March 23, 2002
ATLANTA, Georgia (ACC) -- Both rate
control and rhythm control are reasonable goals in patients with
atrial fibrillation (AF), according to two new studies that
indicated they are at least equal in efficacy.
Results of the AFFIRM (Atrial Fibrillation Follow-up
Investigation in Rhythm Management) and RACE (Rate Control vs.
Electrical Cardioversion for Persistent Atrial Fibrillation)
trials were discussed by their investigators during a news
conference here Monday, March 18, 2002.
AFFIRM randomized patients to medical therapy either to restore
atrial rhythm or to control ventricular heart rate, whereas RACE
compared medical therapy to control heart rate with
electrocardioversion of rhythm.
“Rate control is considered by many physicians as a secondary
strategy for AF,” said D. George Wyse, MD, PhD, of the Cardiac
Arrhythmia Clinic at the University of Calgary in Calgary,
Now, with the AFFIRM trial, continued Dr. Wyse, “We can say that
[rate control] is at least as good as rhythm control and should
be considered a primary strategy.”
AFFIRM randomized 4,060 elderly patients to medical management
of AF. The primary study endpoint, total mortality, was slightly
lower in the rate-control arm, although the trend was not quite
statistically significant, said Dr. Wyse. At an average of 3.5
years of follow-up, there were 306 deaths in the rate-control
arm vs. 356 in the rhythm-control arm.
Outcomes were approximately the same for the two groups in the
secondary endpoint, ischemic stroke, he added.
All patients started the trial on anticoagulant therapy, which
could be discontinued in the rhythm control arms if patients
were thought to be in continuous sinus rhythm. Patients could be
crossed over to the alternate trial arm if necessary, although
Dr. Wyse noted that the analysis was done on an intent-to-treat
Dr. Wyse said the trial results were pertinent to everyday
practice because patients enrolled were older than 65, unless
they had other risk factors. AF is prevalent among the elderly,
Dr. Wyse said, noting that it is found in 8 percent of people
over age 80.
The difference between primary endpoints in the RACE study was
The rate of death or severe cardiovascular incident was 17.2
percent among the 256 patients in the rate-control trial arm vs.
22.6 percent among the 266 patients in the electrocardioversion
rhythm-control arm, said Harry J. Crijns, MD, of the Department
of Cardiology at University Hospital Maastricht in Maastricht,
Cardiovascular mortality rates were 7.0 percent for the
rate-control arm and 6.7 percent for the rhythm-control arm;
heart failure rates were 3.5 percent and 4.5 percent,
respectively; and bleeding complication rates were 4.7 percent
and 3.4 percent, respectively.
“Patients with hypertension in particular did not do well with
electrocardioversion for rhythm control,” Dr. Crijns said. The
rate of mortality, thromboembolism, or other severe complication
was approximately 19 percent for rate-control therapy vs.
approximately 31 percent for rhythm control. Dr. Crijns
speculated that some factor in electroconversion might be
especially thrombogenic in hypertensive patients.
“Rate control is not inferior to rhythm control, and it appears
to be a very attractive alternative, especially for patients
with a high risk of AF recurrence,” Dr. Crijns concluded, adding
that it is important to develop safer and more effective