EGM Burden Reduction
By selecting up to 3 key EGMs of each arrhythmia type per day for
review, the total arrhythmia EGM burden of this patient population
reduced by 55.1%, from 95,716 to 42,930. Specifically, 35,723 AF EGMs
were reduced by 43.2% to 20,295; 12,239 tachycardia EGMs were reduced
by 66.5% to 4,104; 19,752 bradycardia EGMs were reduced by 76.9% to
4,558; and 28,002 pause EGMs were reduced by 50.1% to 13,973, as shown
in Figure 2 (top panel). The subpopulation of “high EGM-volume
patients” were identified as those in the top 25thpercentile of EGMs/patient/month for each arrhythmia type (i.e.,
patients with ≥7.9 AF, ≥2.6 tachycardia, ≥6.4 bradycardia, or ≥6.7 pause
EGMs/pt/mo). Interestingly, these 263/869 patients contributed 89.7% of
the total arrhythmia EGM burden (85,830/95,716 EGMs). As expected, the
EGM burden reduction was more pronounced in these high EGM-volume
patients, and reduced by 59.6%, from 85,830 to 34,707. Specifically,
30,801 AF EGMs reduced by 47.8% to 16,071; 10,959 tachycardia EGMs
reduced by 72.0% to 3,072; 18,262 bradycardia EGMs reduced by 80.8% to
3,506; and 25,808 pause EGMs reduced by 53.3% to 12,058 on these high
EGM-volume patients, as shown in Figure 2 (bottom panel).
On a per-patient, per-month basis, AF median EGMs/pt/mo reduced from 1.8
[0.4, 7.9] by 14.0% (patient-wise median reduction) to 1.5 [0.4,
6.7]; tachycardia median EGMs/pt/mo reduced from 0.6 [0.2, 2.6] by
20.4% to 0.5 [0.2, 1.5]; bradycardia median EGMs/pt/mo reduced from
1.3 [0.3, 6.4] by 25.7% to 0.9 [0.3, 3.7]; and pause median
EGMs/pt/mo reduced from 0.9 [0.2, 6.7] by 6.7% to 0.9 [0.2,
4.5], as shown in Figure 3 (top panel, P<0.001 for
each arrhythmia type). These median reductions in the EGMs/patient/month
magnified in the top 25th percentile EGM-contributing
patients for each arrhythmia type. In these high EGM-volume subgroup, AF
median EGMs/pt/mo reduced from 24.2 [14.4, 48.9] by 37.7% to 15.1
[9.4, 27.0]; tachycardia median EGMs/pt/mo reduced from 7.5 [4.8,
15.7] by 53.0% to 3.5 [2.0, 5.6]; bradycardia median EGMs/pt/mo
reduced from 26.1 [12.4, 53.0] by 70.8% to 7.6 [5.1, 13.5]; and
pause median EGMs/pt/mo reduced from 26.7 [12.7, 53.7] by 48.1% to
13.8 [7.7, 26.0], as shown in Figure 3 (bottom panel,
P<0.001 for each arrhythmia type).