Abstract 9316: Intermittent Pattern of Atrial Fibrillation: An Extremely High Risk for Subsequent Stroke in the General Population.
Objectives: Atrial fibrillation (AF) is a well-known risk factor of stroke. In clinical practice, permanent AF is usually given importance over intermittent forms such as paroxysmal and persistent AF. We assessed the hypothesis that intermittent AF is also an important risk factor of stroke.
Methods: From among the participants of the annual health examinations for the residents of Ibaraki Prefecture, Japan, from 2003 to 2007, 111,062 subjects (mean age: 65.2 years, 34% men) who had participated for five consecutive years were enrolled. The annual presence or absence of AF during these five years, as confirmed by electrocardiogram, differentiated 25 = 32 patterns of AF appearance. Based on the number (n–5) of times AF was detected, subjects were divided into six groups (AF0, AF1, AF2, AF3, AF4, and AF5). The AF2 and AF3 groups included subjects with intermittent AF, whereas the AF5 group included subjects with permanent AF. Stroke history (infarction, hemorrhage, and subarachnoid hemorrhage) was compared among the groups. A new onset of stroke during the examination period in each group was calculated as a difference of prevalence between 2003 and 2007.
Results: During the five years, 1,570 subjects (1.4% of the subjects) had at least one AF. AF1, AF2, AF3, AF4, and AF5 groups included 25%, 13%, 8%, 11%, and 43% of AF subjects, respectively. Stroke prevalence observed in 2003 in the AF0, AF1, AF2, AF3, AF4, and AF5 groups was 1.8%, 4.1%, 6.4%, 4.8%, 5.8%, and 8.3%, respectively, with the highest prevalence in the AF5 group; whereas, new onset of stroke from 2003 to 2007 was 1.4%, 4.1%, 5.9%, 10.4%, 5.8%, and 5.5% in the AF0, AF1, AF2, AF3, AF4, and AF5 groups, respectively. Subsequent occurrence of stroke was significantly more frequent in AF3 than in AF1 (p < 0.01) or AF5 (p < 0.05) groups.
Conclusions: Intermittent pattern of AF is an extremely high risk factor for subsequent stroke. Thus, in the management of AF, aggressive prevention of stroke is necessary in intermittent AF.
- © 2010 by American Heart Association, Inc.