FUSTER
ET AL., ACC/AHA/ESC GUIDELINES FOR THE MANAGEMENT OF
PATIENTS WITH ATRIAL FIBRILLATION
J Am Coll Cardiol 2001;38:1266i-1xx
ACC/AHA/ESC
Guidelines for the Management of Patients with Atrial
Fibrillation
IV.
Epidemiology and Prognosis
AF
is the most common arrhythmia encountered in clinical
practice, accounting for approximately one third of
hospitalizations for cardiac rhythm disturbance. It
has been estimated that 2.2 million Americans have paroxysmal
or persistent AF (11).
Most of the data regarding the epidemiology, prognosis,
and quality of life in AF have been obtained in North
America and western Europe.
A.
Prevalence
The
prevalence of AF is estimated at 0.4% of the general
population, increasing with age (12).
Cross-sectional studies have found the prevalence to
be less than 1% in those under 60 years of age and greater
than 6% in those over 80 years (13-15)
(Figure 4). The age-adjusted
prevalence is higher in men (15,16).
Based on limited data, the age-adjusted risk of developing
AF in blacks appears to be less than half that in whites
(17,18).
In
population-based studies, the frequency of AF in patients
with no history of cardiopulmonary disease (lone AF)
was less than 12% of all cases of AF (Figure
5) (10,15,19,20).
In some series, however, the observed frequency of lone
AF was over 30% (21,22).
AF is prevalent in patients with congestive HF or valvular
heart disease and increases in prevalence with the severity
of these conditions (Table 1).
B.
Incidence
In
prospective studies, the incidence of AF increased from
less than 0.1% per year in those under 40 years of age
to greater than 1.5% per year in women over 80 years
of age and greater than 2% per year in men over 80 years
of age (17,23,24)
(Figure 6). The age-adjusted
incidence increased over a 30-year period in the Framingham
Study (23),
and this may have implications for the future impact
of AF on the population. During 38 years of follow-up
in the Framingham Study, 20.6% of men who developed
AF had congestive HF at inclusion vs. 3.2% of those
without AF; the corresponding incidences in women were
26.0% and 2.9% (25).
In patients referred for treatment of HF, the 2- to
3-year incidence of AF was 5% to 10% (17,26,27).
The incidence of AF may be lower in HF patients treated
with angiotensin converting enzyme inhibitors (28).
C.
Prognosis
The
rate of ischemic stroke among patients with nonrheumatic
AF averages 5% per year, which is between 2 and 7 times
that of people without AF (13,14,21,23,24,28)
(Figure 7). One of every 6
strokes occurs in patients with AF (29).
Additionally, when transient ischemic attacks and clinically
occult "silent" strokes detected radiographically
are considered, the rate of brain ischemia accompanying
nonvalvular AF exceeds 7% per year (25,30-33).
In patients with rheumatic heart disease and AF, stroke
risk was increased 17-fold compared with age-matched
controls in the Framingham Heart Study (34),
and attributable risk was 5 times greater than in those
with nonrheumatic AF (14).
AF doubled the risk of stroke in the Manitoba Follow-up
Study independently of other risk factors (24),
and the relative risks for stroke in nonrheumatic AF
were 6.9% and 2.3% in the Whitehall and the Regional
Heart studies, respectively. Among AF patients from
general practices in France, the ALFA Study (Etude en
Activité Liberale sur le Fibrillation Auriculaire)
found a 2.4% incidence of thromboembolism over a mean
of 8.6 months of follow-up (21).
The risk of stroke increases with age; in the Framingham
Study, the annual risk of stroke attributable to AF
increased from 1.5% in participants aged 50 to 59 years
to 23.5% for those aged 80 to 89 years (14).
The
mortality rate of patients with AF is about double that
of patients in normal sinus rhythm and is linked with
the severity of underlying heart disease (13,16,24)
(Figure 7). About two thirds
of the 3.7% mortality over 8.6 months in the ALFA study
was attributed to cardiovascular causes (21).
In patients with mild to moderate HF, however, the data
are mixed. The V-HeFT studies (Veterans Administration
Heart Failure Trials) did not find increased mortality
among patients with concomitant AF (35),
whereas in the SOLVD trial (Studies of Left Ventricular
Dysfunction), mortality was 34% for those with AF vs.
23% for patients in sinus rhythm (p less than 0.001)
(36).
The difference was attributed mainly to an increased
number of deaths due to HF rather than to thromboembolism.
Copyright
© 2001 by the American College of Cardiology, American
Heart Association, Inc., and the European Society of
Cardiology
Published by Elsevier Science Inc.
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