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Pulse pressure identified as important risk factor for atrial fibrillation

February 21, 2007

Increased pulse pressure (the difference between systolic and diastolic blood pressure) appears to be an important predictor of the risk for new onset atrial fibrillation, according to a study in the February 21 issue of JAMA.

Atrial fibrillation (AF) is the most common chronic arrhythmia in adults and is associated with increased risk for death and stroke. An estimated 2.3 million adults in the United States have AF, and that number is expected to increase substantially as the population ages, making identification of modifiable risk factors important. The prevalence of AF increases with age, with a substantial overall lifetime risk of approximately 1 in 4 for both men and women, according to background information in the article. The increase in AF incidence with age coincides with a rapid age-related increase in aortic stiffness, which is associated with increased pulse pressure, which increases cardiac load and may increase AF risk.

Gary F. Mitchell, M.D., of Cardiovascular Engineering Inc., Waltham, Mass., and colleagues examined the association between pulse pressure and the development of AF. The study included 5,331 participants of the Framingham Heart Study who were age 35 years and older and initially free from AF (median [midpoint] age, 57 years; 55 percent women).

During an average of 16 years of follow-up, 363 men and 335 women developed AF with a median time-to-event of 12 years after pulse pressure assessment. The researchers found that after adjusting for age and sex, a 20 mm Hg increase in pulse pressure was associated with a 34 percent increase in the risk for developing AF. The association between pulse pressure and AF remained significant after further adjusting for average arterial pressure and clinical risk factors for AF; each 20 mm Hg increase in pulse pressure was associated with a 24 percent increase in the risk for developing AF. In contrast, average arterial pressure was not associated with increased risk for developing AF.

Cumulative 20-year AF incidence rates were 5.6 percent for pulse pressure of 40 mm Hg or less (25th percentile) and 23.3 percent for pulse pressure greater than 61 mm Hg (75th percentile).

"In summary, we have shown that increased pulse pressure, a simple and readily accessible if somewhat indirect measure of arterial stiffness, is likely an important risk factor for development of AF in a community-based sample. Arterial stiffness increases with advancing age, even in a relatively healthy sample. However, increased arterial stiffness with advancing age is not inevitable and appears to be modifiable [such as by reducing various cardiovascular disease risk factors]. As a result, increased arterial stiffness may represent a major modifiable risk factor for development of AF."

"Given the aging of the population, further research is needed to determine whether interventions aimed at reducing pulse pressure or preventing the increase in pulse pressure with advancing age effectively reduce the incidence of AF. In light of the variable and often substantial increase in pulse pressure that accompanies advancing age, lifestyle modifications or therapy aimed specifically at reducing or limiting the increase in pulse pressure with advancing age may markedly reduce the substantial and rapidly growing incidence of AF in our aging society," the authors write.

JAMA and Archives Journals