Abstract 9107: Orthostatic Blood Pressure Change is Associated with Incident Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study
Background: Efferent autonomic fluctuations often precede episodes of atrial fibrillation (AF). Whether orthostatic blood pressure change, a common manifestation of autonomic dysfunction, is associated with incident AF remains unknown.
Methods: We examined whether supine-to-standing changes in systolic BP are associated with incidence of AF in 12,122 African American and white men and women aged 45–65 years, enrolled from four US communities. Orthostatic hypotension (OH) defined as a drop in systolic blood pressure (BP) by >=20 mm Hg or diastolic BP by >=10 mm Hg. AF cases were identified from 12-lead electrocardiograms recorded triennially at three scheduled follow-up visits through 1998, and from hospitalizations and death certificates through 2005.
Results: During an average follow up of 15.4 years, 936 (7.7%) of the study participants had AF. Incident AF occurred in 13.1% of those with OH at baseline (5% of study sample) compared to 7.5% of those without OH. Age adjusted rates of AF per 1000 person-year by quintiles (decreasing order) of orthostatic drop in systolic BP were 5.6, 5.1, 4.7, 3.8, and 4.9. The age, gender, and race adjusted hazard ratio (HR) 95% confidence interval (95% CI) of AF comparing those with OH to those without was 1.70 (1.34, 2.14). This association was modestly attenuated after adjustment for demographics and common AF risk factors Hazard ratio (95%CI) = 1.51 (1.19, 1.92). Interestingly, a U-shaped relationship between orthostatic change in systolic BP and incident AF was present after multivariable adjustment (Figure 1).
Conclusions: Results from this large prospective study in community settings suggest that an exaggerated response to orthostatic changes in BP (low or high) is associated with incident AF. Thus, poor cardiac autonomic modulation, as indexed by orthostatic change in BP, may play a role in initiation or maintenance of AF.
Figure Orthostatic change in BP and multivariable adjusted hazard ratio of atrial fibrillation
- © 2010 by American Heart Association, Inc.