Interim evaluation of insertable cardiac monitor signal quality in the LUX-Dx PERFORM study

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: Private company. Main funding source(s): Boston Scientific Corporation BACKGROUND: The LUX-Dx PERFORM Study is designed to evaluate safety and performance of the LUX-Dx Insertable Cardiac Monitor (ICM) in a general patient population. Although follow-up is ongoing, enrollment is complete, and at least half of the patients have completed 180 days of follow-up. The visibility (or absence) of P-waves in the ICM-recorded S-ECG is an important feature in the diagnosis of atrial arrhythmias. OBJECTIVE: Evaluate the visibility of P-waves in patients enrolled in the LUX-Dx PERFORM study. METHODS: P-wave visibility was evaluated from the first 356 patients enrolled in the LUX-Dx PERFORM study. The daily presenting S-ECGs (10 second rhythm) nearest to Day 7 (+/- 1) and Day 180 (+/- 7) after implant were blindly adjudicated by independent electrophysiologists to calculate the percentage of beats with clearly visible P-waves. RESULTS: Of 636 reviewed S-ECGs, 24 (3.7%) were excluded from analysis for presence of AF rhythm (11), or unavailable data (8 with insufficient adjudication and 5 with no detected R-waves from which to calculate the percentage of beats with visible P-waves). Figure 1 shows an example of a presenting S-ECG rhythm with clearly visible P-waves from the patient management system LATITUDE Clarity. The P-waves were found to be clearly visible in 89.1% of the total heart cycles (Day 7: 90.4%, Day 180: 87.8%). The average difference in percent visibility between Day 7 and Day 180 was approximately 2.2% (p=.248). At a patient level, 88% of patients had visible P-waves in at least one presenting ECG for more than 90% of beats, as shown in Figure 2. In addition, 69% of patients had visible P-waves in both presenting ECGs (Day 7 and Day 180) for at least 90% of beats. CONCLUSION: The LUX-Dx showed consistent visibility of P-waves in the first half of patients enrolled in the LUX-Dx PERFORM study, which represents a general patient population. Adequate P-wave visibility is an important clinical feature in diagnosing atrial arrhythmias and may aid in analysis and clinic workflow efficiency. [Figure: see text] [Figure: see text]