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Pulse Pressure is a Risk Factor for New-Onset Atrial Fibrillation (AF)

March 6, 2007

By Laurie Brunette and Asher Kimchi M.D.

Waltham, MA- Atrial fibrillation is associated with an increased risk of mortality and stroke, and every one in four people will develop AF at some point in their lifetime. Already recognized clinical risk factors for AF include advancing age, increased systolic blood pressure, diabetes, hypertension, heart failure, valvular disease, myocardial infarction, and obesity. Echocardiographic risk factors for AF include left atrial enlargement, increased left ventricular wall thickness, and impaired left ventricular systolic function. Gary F. Mitchell, MD et al from the Cardiovascular Engineering Inc. in Waltham, MA investigated whether pulse pressure, a reflection of aortic stiffness, could be a potentially easily modifiable risk factor for AF. Their study, published in the February 21, 2007 issue of The Journal of the American Medical Association, found that pulse pressure is in fact an important risk factor for incident AF in a community-based sample.

The study included 5331 participants (55% women) of the Framingham Heart Study who were aged 35 years and older with no past or current findings of AF or atrial flutter on electrocardiogram. At each examination (every 2-8 years, censored at 20 years), a medical history, physical examination, and electrocardiography were administered. A standardized 2-dimensional guided M-mode echocardiogram was also performed at the baseline examination.

AF developed in 698 participants (13.1%), a median of 12 years after pulse pressure assessment. In models adjusted for age, sex, baseline and time-dependent change in mean arterial pressure, and clinical risk factors for AF (body mass index, smoking, valvular disease, diabetes, electrocardiographic left ventricular hypertrophy, hypertension treatment, and prevalent myocardial infarction or heart failure), pulse pressure was associated with an increased risk for AF (adjusted hazard ratio [HR], 1.26 per 20-mm Hg increment; 95% confidence interval [CI], 1.12-1.43; P<.001). Mean arterial pressure was found to be unrelated to new-onset AF (adjusted HR, 0.96 per 10-mm Hg increment; 95% CI, 0.88-1.05; P=.39). Systolic pressure was related to AF (HR, 1.14 per 20-mm Hg increment; 95% CI, 1.04-1.25; P=.006); but with the addition of diastolic pressure, model fit improved and the diastolic relation was inverse (adjusted HR, 0.87 per 10-mm Hg increment; 95% CI, 0.78-0.96; P=.01). This is consistent with a pulse pressure effect. The association between pulse pressure and AF persisted in models that adjusted for baseline left atrial dimension, left ventricular mass, and left ventricular fractional shortening (adjusted HR, 1.23; 95% CI, 1.09-1.39; P=.001).

In conclusion, arterial stiffness, as evidenced by elevated pulse pressure, represents a potentially modifiable risk factor for AF. Mitchell et al has shown that pulse pressure is the single blood pressure component most predictive of future development of AF. Interventions known to reduce pulse pressure, such as blockade of the renin-angiotensin system, have been shown to reduce the incidence of new or recurrent AF. Further research is needed to determine whether other interventions aimed at reducing pulse pressure or preventing the increase in pulse pressure with advancing age effectively reduce the incidence of AF.

Co-authors: Ramachandran S. Vasan, MD; Michelle J. Keyes, MA; Helen Parise, ScD; Thomas J. Wang, MD; Martin G. Larson, ScD; Ralph B. D’Agostine, Sr, PhD; William B. Kannel, MD, MPH; Daniel Levy, MD; Emelia J. Benjamin, MD, ScM. 

 


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