The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study: approaches to control rate in atrial fibrillation.
OBJECTIVE
We sought to evaluate approaches used to control rate, the effectiveness of rate control, and switches from one drug class to another in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.


BACKGROUND
The AFFIRM study showed that atrial fibrillation (AF) can be treated effectively with rate control and anticoagulation, but drug efficacy to control rate remains uncertain.


METHODS
Patients (n = 2,027) randomized to rate control in the AFFIRM study were given rate-controlling drugs by their treating physicians. Standardized rate-control efficacy criteria developed a priori included resting heart rate and 6-min walk tests and/or ambulatory electrocardiographic results.


RESULTS
Average follow-up was 3.5 +/- 1.3 years. Initial treatment included a beta-adrenergic blocker (beta-blocker) alone in 24%, a calcium channel blocker alone in 17%, digoxin alone in 16%, a beta-blocker and digoxin in 14%, or a calcium channel blocker and digoxin in 14% of patients. Overall rate control was achieved in 70% of patients given beta-blockers as the first drug (with or without digoxin), 54% with calcium channel blockers (with or without digoxin), and 58% with digoxin alone. Adequate overall rate control was achieved in 58% of patients with the first drug or combination. Multivariate analysis revealed an association between first drug class and several clinical variables. There were more changes to beta-blockers than to the other two-drug classes (p < 0.0001).


CONCLUSIONS
Rate control in AF is possible in the majority of patients with AF. Beta-blockers were the most effective drugs. To achieve the goal of adequate rate control in all patients, frequent medication changes and drug combinations were needed.
Olshansky
Brian
B
University of Iowa, Iowa City, Iowa 52242, USA. brian-olshansky@uiowa.edu
Rosenfeld
Lynda E
LE
Warner
Alberta L
AL
Solomon
Allen J
AJ
O'Neill
Gearoid
G
Sharma
Arjun
A
Platia
Edward
E
Feld
Gregory K
GK
Akiyama
Toshio
T
Brodsky
Michael A
MA
Greene
H Leon
HL
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000628:therapy; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D017115:Catheter Ablation; D004077:Digoxin / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010138:Pacemaker, Artificial; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D016896:Treatment Outcome
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002121:Calcium Channel Blockers; D004077:Digoxin