Implantable cardioverter defibrillator electrogram adjudication for device registries: methodology and observations...

Area of Science:

• Cardiology
• Biomedical Engineering
• Health Informatics

Background:

• Remote monitoring systems generate vast implantable cardioverter-defibrillator (ICD) electrogram (EGM) databases.
• Adjudicating these large EGM datasets presents significant challenges.
• The ALTITUDE study utilized the LATITUDE remote monitoring system to assess ICD patient outcomes in the U.S.

Purpose of the Study:

• To develop and evaluate an online adjudication system for ICD EGM data.
• To assess the agreement of rhythm classification among electrophysiologists.
• To determine the impact of device type (single- vs. dual-chamber) on adjudication agreement.

Main Methods:

• A random sample of 2,000 patients with 5,279 shock episodes was selected from 81,081 remotely monitored patients.
• Seven electrophysiologists from four institutions adjudicated the EGMs using an online system.
• Light's Kappa statistic was employed to measure interobserver and intraobserver agreement.

Main Results:

• 70% of shock episodes were classified as appropriate therapies, while 30% were inappropriate.
• Substantial interobserver and intraobserver agreement was found for dual-chamber ICDs (Kappa scores 0.84-0.89).
• Moderate agreement was observed for single-chamber ICDs (Kappa scores 0.61-0.69), with greatest discordance in classifying ventricular tachycardias.

Conclusions:

• The developed EGM adjudication method enables new insights into ICD performance.
• This approach can potentially enhance ICD programming and device design.
• Dual-chamber ICDs demonstrated higher adjudication agreement, highlighting the diagnostic value of atrial leads.