Background: Patients with paroxysmal atrial fibrillation (PAF) often report markedly reduced activity levels in daily life, which is associated with adverse outcome. Activity is a modifiable risk factor for AF progression. 

Accelerometer data can be used to objectively assess the daily metabolic equivalent of task (MET) score.

Objective: We aimed to investigate the association between MET score during sinus rhythm (SR) in with and without PAF using a 30-day mobile cardiac telemetry device with integrated accelerometer data.

Methods: 

We performed a retrospective database analysis with n=31.492 patients who recorded an ambulatory ECG with sufficient quality using the PocketECG device (MediLynx) in the US during from 09/2019 until 10/2020. 

Patients between 50 and 85 years were eligible if they had been referred for monitoring with ICD codes I48.xx or R00.2. Exclusion criteria was PAF-burden ≥ 20%. MET score during SR was compared in pts with and without PAF (defined by a duration ≥30s). All PAF episodes were algorithmically detected and manually verified.

Results: The population consisted of 2,701 males and 4,058 females (mean age 70± 8 years males, 70 ± 9 years females). PAF was diagnosed in significantly fewer females compared to males (12.27% vs. 15.59%; p<0.001). Mean AF burden was 3.28 ± 4.63% in females vs. 3.60 ± 4.59% in males (p=n.s) 

Patients with existing PAF had a significantly lower MET score during SR compared to pts without PAF (1.27 vs. 1.36; 95% CI of the difference: [-0.11; -0.07]). By multivariate analysis, female sex and presence of PAF were both independently associated with a reduced MET score during SR.

Conclusion: Patients with PAF are less active during episodes of sinus rhythm than patients without PAF, which could be demonstrated by a reduced MET score.