Diagnostic Impact
By applying the key EGM selection rules, the 2,964 TP AF days were reduced by 0.8% to 2,940; the 1,572 TP tachycardia days were reduced by 2.1% to 1,539; the 1,438 TP bradycardia days were reduced by 0.2% to 1,435; and the 645 TP pause days were unchanged, as shown inFigure 4 (top panel). For high EGM-volume patients, the 2,242 TP AF days were reduced by 0.9% to 2,222; the 1,089 TP tachycardia days were reduced by 3.0% to 1056; the 1,141 TP bradycardia days were reduced by 0.3% to 1,138; and, again, the 368 TP pause days were unchanged, as shown in Figure 4 (bottom panel).
Ultimately, using this key EGM selection strategy introduced no delay in the diagnosis of AF, tachycardia, bradycardia, and pause in 99.3% (145/146), 98.8% (247/250), 99.1% (115/116), and 100.0% (106/106) of patients who exhibited at least one TP EGM of each arrythmia, respectively, as shown in Figure 5 . In other words, despite limiting the EGMs to review, the first day when a TP EGM was reviewed remained the same in the vast majority of patients (99.2% for all arrhythmias combined). Of patients with a TP AF EGM, the single patient with a diagnostic delay resulting from key EGM selection did not exhibit any TP EGMs after the first TP day within the patient’s follow-up period (i.e., no calculable delay). Of patients with a TP tachycardia EGM, 0.8% (2/250) were associated with a diagnostic delay of 9.5 [6.0, 13.0] days; the remaining 1 patient did not exhibit any TP EGMs after the first TP day within the patient’s follow-up period. Of patients with a TP bradycardia EGM, 0.9% (1/116) were associated with a diagnostic delay of 6.0 [6.0, 6.0] days. No patients with a TP pause EGM experienced a diagnostic delay resulting from key EGM selection.
The impact of key EGM selection on time-to-diagnosis is also shown inFigure 6 . Reviewing only key EGMs did not significantly impact the freedom from arrhythmia diagnosis in the first-year of follow-up, as evident by the nearly overlaid trends within each arrhythmia type, as well as the near-unity P values: 0.933 for AF, 0.946 for tachycardia, 0.999 for bradycardia, and 1.000 for pause.