Table 2.
Atrial fibrillation burden as measured using an implantable cardiac monitor
| All observationsa | Baseline | 6 months | 1 year | 2 years | 3 years | Annual change (95% CI) | p value |
|---|---|---|---|---|---|---|---|
| (N = 20) | (N = 19) | (N = 20) | (N = 20) | (N = 19) | |||
| Daily AF burden (min/day), median [25th–75th percentiles] | 1.4 [0.0–10.9] | 0.7 [0.0–31.6] | 1.0 [0.0–15.4] | 0.7 [0.0–19.4] | 0.9 [0.0–7.9] | − 15.4% (− 50.2%, 43.7%) | 0.54 |
| AF episodes (min), median [25th–75th percentiles] | 125.0 [1.5–978.0] | 44.0 [0.0–2833.0] | 91.5 [0.0–1403.5] | 63.9 [0.0–1769.4] | 81.9 [0.4–718.6] | − 14.7% (− 56.2%, 66.3%) | 0.64 |
| Maximal ventricular rate response (beats/minute), mean ± SD | 123.3 ± 23.4 | 120.7 ± 33.8 | 102.1 ± 24.4 | 145.5 ± 30.0 | 145.5 ± 37.7 | 10.6 (2.8, 18.4) beats/minute | 0.009 |
| Patients without any permanent AFb | Baseline | 6 months | 1 year | 2 years | 3 years | Annual change (95% CI) | p value |
|---|---|---|---|---|---|---|---|
| (N = 17) | (N = 16) | (N = 17) | (N = 17) | (N = 16) | |||
| Daily AF burden (min/day), median [25th–75th percentiles] | 1.3 [0.0–6.9] | 0.7 [0.0–29.5] | 0.9 [0.0–3.3] | 0.6 [0.0–5.5] | 0.9 [0.2–6.3] | − 21.4% (− 54.7%, 36.6%) | 0.39 |
| AF episodes (n), median [25th–75th percentiles] | 1.0 [0.8–2.5] | 1.0 [0.0–7.8] | 2.0 [0.0–13.0] | 1.0 [0.0–2.9] | 1.8 [0.3–5.3] | 10.4% (− 28.7%, 71.2%) | 0.66 |
| AF episodes (min), median [25th–75th percentiles] | 119.0 [2.3–617.0] | 34.5 [0.0–2643.5] | 78.0 [0.0–297.0] | 53.7 [0.0–505.1] | 84.7 [18.5–574.9] | − 28.9% (− 67.2%, 54.1%) | 0.39 |
| Maximal ventricular rate response (beats/minute), mean ± SD | 124.8 ± 20.9 | 116.3 ± 32.7 | 106.7 ± 23.4 | 141.6 ± 30.6 | 143.4 ± 42.3 | 9.4 (1.2, 17.6) beats/minute | 0.03 |
All outcomes, including the cumulative duration of AF and the number of AF episodes were reported for 3-month time windows
AF atrial fibrillation, CI confidence interval, SD standard deviation
aAll observations (20 patients with 98 observations) were included. For observations of permanent AF the duration was imputed as 24 h (equal to 1440 min) of AF per day and 2190 h of AF per 3 months
bA subset of 16/20 patients with 78/98 observations was analyzed. All observations for patients experiencing any permanent AF ICM recordings were excluded