Asymptomatic atrial fibrillation: demographic features and prognostic information from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study.
BACKGROUND
Atrial fibrillation (AF) may occur without symptoms. Little is known about demographic features and prognostic information in patients with asymptomatic AF.


METHODS
In the AFFIRM study, 4060 patients were randomized to either rhythm or rate control. At baseline, patients were identified as asymptomatic if they answered "no" to a 15-item questionnaire related to cardiac symptoms during AF in the 6 months before study entry.


RESULTS
There were 481 (12%) asymptomatic patients at baseline. Compared with symptomatic patients, asymptomatic patients were more often men and had a lower incidence of coronary artery disease and congestive heart failure, but had more cerebrovascular events. Asymptomatic patients had a longer duration of AF, a lower maximum heart rate, and better left ventricular function. They received fewer cardiac medications and fewer therapies to maintain sinus rhythm. At 5 years, there was a trend for better survival in asymptomatic patients (81% vs 77%, P = .058), and they were more likely to be free from disabling stroke or anoxic encephalopathy, major bleeding, and cardiac arrest (79% vs 67%, P = .024). However, mortality and major events were similar after correction for baseline differences.


CONCLUSIONS
Patients with asymptomatic AF have less serious heart disease but more cerebrovascular disease. Asymptomatic patients receive different therapies than symptomatic patients. However, the absence of symptoms and the differences in treatment does not confer a more favorable prognosis when differences in baseline clinical parameters are considered. Anticoagulation should be considered in these patients.
Flaker
Greg C
GC
University of Missouri-Columbia School of Medicine, Columbia, Mo 65212, USA. flakerg@health.missouri.edu
Belew
Kathy
K
Beckman
Karen
K
Vidaillet
Humberto
H
Kron
Jack
J
Safford
Robert
R
Mickel
Mary
M
Barrell
Patrick
P
D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000453:epidemiology* / Q000601:surgery / Q000628:therapy; D002423:Cause of Death; D002561:Cerebrovascular Disorders / Q000453:epidemiology; D015897:Comorbidity; D003327:Coronary Disease / Q000453:epidemiology; D004554:Electric Countershock; D005260:Female; D005500:Follow-Up Studies; D006323:Heart Arrest / Q000453:epidemiology; D006333:Heart Failure / Q000453:epidemiology; D006470:Hemorrhage / Q000139:chemically induced / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011788:Quality of Life; D012959:Socioeconomic Factors; D016019:Survival Analysis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000453:epidemiology
D000889:Anti-Arrhythmia Agents; D000925:Anticoagulants