Pulse pressure a risk factor for AF

Elevated pulse pressure is an important risk factor for atrial fibrillation, a paper in JAMA has concluded. Atrial fibrillation (AF) is the most common chronic arrhythmia in adults and is associated with increased risk for mortality and stroke, Gary Mitchell (Cardiovascular Engineering Inc., Waltham, Massachusetts, USA) and colleagues explain. The exponential rise in AF incidence with age parallels a rapid age-related increase in aortic stiffness. The concomitant increase in pulse pressure adds to pulsatile load on the heart, thereby promoting ventricular hypertrophy, impaired ventricular relaxation, and increased left atrial size.Elevated left atrial size and pressure and impaired ventricular diastolic function may lead to fibrosis and electrical remodeling in the atrium, providing a substrate for the development of AF. Mitchell et al. hypothesized that pulse pressure may represent an easily measured and potentially modifiable risk factor for the development of AF in the large community-based Framingham Study sample. The team prospectively studied the rate of incident AF in 5331 Framingham Heart Study participants aged 35 years or older who were initially AF-free. Over an average follow-up of 16 years, 698 (13.1%) participants developed AF a median of 12 years after pulse pressure assessment. Cumulative 20-year AF incidence rates were 5.6% among those with pulse pressure below the 25th percentile (61 mmHg). After adjusting for age and gender, a 20-mmHg rise in pulse pressure was associated with a 34% increase in the risk for developing AF, after adjusting for age and gender (hazard ratio [HR]=1.34, pThis association remained significant after further adjustment for mean arterial pressure and clinical risk factors for AF (HR per 20-mmHg increase=1.24, pIn contrast, mean arterial pressure (the diastolic pulse pressure added to one third of the pulse pressure) was not associated with the risk of AF. "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," the authors write. "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," they conclude. Reference...