Patient Activity Decreases and Mortality Increases After the Onset of Persistent Atrial Fibrillation in Patients With Implantable Cardioverter-Defibrillators

Objectives: The study sought to determine the effect of persistent atrial fibrillation (AF) on device-measured activity and mortality.

Background: Patients with AF often complain of fatigue, which may be reflected in patient activity. Daily activity can be objectively measured by implanted devices.

Methods: We retrospectively studied patients (n = 266, 88% male, 69 ± 10 years of age) from the deidentified Medtronic CareLink database with persistent AF (≥28 consecutive days with ≥23 h of AF/day), dual-chamber implantable cardioverter-defibrillators (ICDs) capable of monitoring daily activity and AF burden, no AF between months 1 and 6 post-implant, and ≥1 year of data.

Results: The first persistent AF episode occurred 980 ± 534 days after implant and lasted a median of 87 days (interquartile range: 49 to 161 days). Average daily activity over a week just prior (baseline) to the first persistent AF episode was compared to each of the 4 weeks during the AF episode and to each of the weeks following termination of the persistent AF episode. Daily activity decreased significantly from the baseline week (135 min/day) compared to each of the 4 consecutive weeks after AF onset (8%, 11%, 14%, and 17% decrease, p < 0.001). Mortality at 4 years was increased in patients with persistent AF compared to a matched group with no persistent AF (20.6% vs. 8.6%, p < 0.01).

Conclusions: Patients with ICDs have a significant reduction in activity following the onset of persistent AF and a significant increase in mortality when compared to a matched group without persistent AF. Objective measures of activity may more accurately reflect the impact of persistent AF on patients' functional status.