Relationships between sinus rhythm, treatment, and survival in the Atrial Fibrillation Follow-Up Investigation of Rhythm Management (AFFIRM) Study.
BACKGROUND
The AFFIRM Study showed that treatment of patients with atrial fibrillation and a high risk for stroke or death with a rhythm-control strategy offered no survival advantage over a rate-control strategy in an intention-to-treat analysis. This article reports an "on-treatment" analysis of the relationship of survival to cardiac rhythm and treatment as they changed over time.


RESULTS
Modeling techniques were used to determine the relationships among survival, baseline clinical variables, and time-dependent variables. The following baseline variables were significantly associated with an increased risk of death: increasing age, coronary artery disease, congestive heart failure, diabetes, stroke or transient ischemic attack, smoking, left ventricular dysfunction, and mitral regurgitation. Among the time-dependent variables, the presence of sinus rhythm (SR) was associated with a lower risk of death, as was warfarin use. Antiarrhythmic drugs (AADs) were associated with increased mortality only after adjustment for the presence of SR. Consistent with the original intention-to-treat analysis, AADs were no longer associated with mortality when SR was removed from the model.


CONCLUSIONS
Warfarin use improves survival. SR is either an important determinant of survival or a marker for other factors associated with survival that were not recorded, determined, or included in the survival model. Currently available AADs are not associated with improved survival, which suggests that any beneficial antiarrhythmic effects of AADs are offset by their adverse effects. If an effective method for maintaining SR with fewer adverse effects were available, it might be beneficial.
Axio Research Corporation, Seattle, Wash, USA.
Scott D
SD
Corley
Andrew E
AE
Epstein
John P
JP
DiMarco
Michael J
MJ
Domanski
Nancy
N
Geller
H Leon
HL
Greene
Richard A
RA
Josephson
Joyce C
JC
Kellen
Richard C
RC
Klein
Andrew D
AD
Krahn
Mary
M
Mickel
L Brent
LB
Mitchell
Joy Dalquist
JD
Nelson
Yves
Y
Rosenberg
Eleanor
E
Schron
Lynn
L
Shemanski
Albert L
AL
Waldo
D George
DG
Wyse
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000638:Amiodarone / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects / Q000627:therapeutic use; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D003131:Combined Modality Therapy; D015897:Comorbidity; D004077:Digoxin / Q000627:therapeutic use; D004554:Electric Countershock; D005500:Follow-Up Studies; D006339:Heart Rate; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D010627:Phenethylamines / Q000627:therapeutic use; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013449:Sulfonamides / Q000627:therapeutic use; D016019:Survival Analysis; D017211:Treatment Failure; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D000925:Anticoagulants; D002121:Calcium Channel Blockers; D010627:Phenethylamines; D013449:Sulfonamides; D014859:Warfarin; D004077:Digoxin; D000638:Amiodarone; C063533:dofetilide