Among older adults, incident or persistent atrial fibrillation (AF) is associated with a reduction in physical activity, according to recent data.
In the Health ABC (Health, Aging, and Body Composition) study, published in Circulation: Arrhythmia and Electrophysiology, researchers examined the associations of incident AF and 4-year interval declines in physical performance at 70, 74, 78, and 82 years of age.
Researchers conducted serial assessments of physical performance, using a physical performance battery (PPB) in 2753 older adults, more than half of whom were women. The battery used a scale from 0 to 4 and measured grip strength, 2-minute walking distance, and 400-meter walking time.
After multivariable adjustment, which included body mass index, systolic and diastolic blood pressure, smoking, alcohol use, cholesterol, creatinine, patients with AF had greater 4-year PPB decline than the patients without AF.
The differences in 4-year physical function decline between patients with and without incident AF was –0.08 at age 70 (95% confidence interval [CI]: –0.16 to –0.01; P=.023), –0.09 at age 74 (95% CI: –0.16 to –0.01; P=.023), –0.09 at age 78 (95% CI: –0.17 to –0.01; P=.023), and –0.10 at age 82 (95% CI: –0.18 to –0.01; P=.024).
At each age interval, patients with AF also showed significantly greater declines in grip strength, walk distance, and walk time.
“We hypothesize that AF is a marker of the frailty syndrome and exacerbates the multisystem decline in physical performance in aging-related pathophysiology,” the authors concluded. “It is also quite possible that AF and physical decline share some other underlying neuroendocrine or neuromuscular cause.”
In a separate study published in JACC: Clinical Electrophysiology, researchers examined the effect of persistent AF on mortality and activity monitored by implantable cardioverter defibrillators (ICDs). They retrospectively analyzed 266 patients, most of whom in this case were men, (average age:69 ± 10 years) from the Medtronic Carelink database.
All patients had persistent AF lasting at least 28 consecutive days for at least 23 hours per day. Additional inclusion criteria included dual chamber ICDs capable of monitoring daily activity and AF burden, no AF between 1 and 6 months post-implant, and at least 1 year of data.
On average, the first episode of persistent AF occurred 980 ± 534 days post-implant and lasted a median of 87 days (interquartile range: 49-161 days). Researchers compared the average daily activity over the course of 1 week prior (baseline) to the first persistent AF episode to each of the 4 weeks during the AF episode and to each of the weeks after the termination of said episode.
The rate of daily activity decreased significantly from 135 minutes per day at the baseline to week to each of the 4 weeks post-AF onset (8%, 11%, 14%, and 17% decrease; P<.001). The mortality rate at 4 years also increased among patients with persistent AF compared with those without AF (20.6% vs 8.6%; P<.01).
The authors noted that “measurements of activity may provide an additional and accessible tool in patients with devices to assess the impact of AF on patient activity and guide sinus rhythm restoration strategies.”
Researchers of both studies concluded that additional research is necessary to clarify the relationship between onset AF and physical activity.
- Chelu MG, Gunderson BD, Koehler J, et al. Patient activity decreases and mortality increases after the onset of persistent atrial fibrillation in patients with implantable cardioverter defibrillators. JACC Clin Electrophysiol. 2016. doi:10.1016/j.jacep.2016.01.015.
- Magnani J, Wang N, Benjamin E, et al; for the Health, Aging, and Body Composition Study. Atrial fibrillation and declining physical performance in older adults: the health, aging and body composition study (Health ABC). Circ Arrhythm Electrophysiol. 2016. doi: 10.1161/CIRCEP.115.003525.