Lenient versus strict rate control in patients with atrial fibrillation.
BACKGROUND
Rate control is often the therapy of choice for atrial fibrillation. Guidelines recommend strict rate control, but this is not based on clinical evidence. We hypothesized that lenient rate control is not inferior to strict rate control for preventing cardiovascular morbidity and mortality in patients with permanent atrial fibrillation.


METHODS
We randomly assigned 614 patients with permanent atrial fibrillation to undergo a lenient rate-control strategy (resting heart rate <110 beats per minute) or a strict rate-control strategy (resting heart rate <80 beats per minute and heart rate during moderate exercise <110 beats per minute). The primary outcome was a composite of death from cardiovascular causes, hospitalization for heart failure, and stroke, systemic embolism, bleeding, and life-threatening arrhythmic events. The duration of follow-up was at least 2 years, with a maximum of 3 years.


RESULTS
The estimated cumulative incidence of the primary outcome at 3 years was 12.9% in the lenient-control group and 14.9% in the strict-control group, with an absolute difference with respect to the lenient-control group of -2.0 percentage points (90% confidence interval, -7.6 to 3.5; P<0.001 for the prespecified noninferiority margin). The frequencies of the components of the primary outcome were similar in the two groups. More patients in the lenient-control group met the heart-rate target or targets (304 [97.7%], vs. 203 [67.0%] in the strict-control group; P<0.001) with fewer total visits (75 [median, 0], vs. 684 [median, 2]; P<0.001). The frequencies of symptoms and adverse events were similar in the two groups.


CONCLUSIONS
In patients with permanent atrial fibrillation, lenient rate control is as effective as strict rate control and is easier to achieve. (ClinicalTrials.gov number, NCT00392613.)
Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. i.c.van.gelder@thorax.umcg.nl
Isabelle C
IC
Van Gelder
Hessel F
HF
Groenveld
Harry J G M
HJ
Crijns
Ype S
YS
Tuininga
Jan G P
JG
Tijssen
A Marco
AM
Alings
Hans L
HL
Hillege
Johanna A
JA
Bergsma-Kadijk
Jan H
JH
Cornel
Otto
O
Kamp
Raymond
R
Tukkie
Hans A
HA
Bosker
Dirk J
DJ
Van Veldhuisen
Maarten P
MP
Van den Berg
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers