A Modular Communicative Leadless Pacing–Defibrillator System

Quick Takes

  • In the cohort study of a modular leadless pacemaker in a wireless environment of the subcutaneous ICD, the percentage of patients who were free from leadless pacemaker–related major complications was 97.5%, and wireless-device communication was successful in 98.8% of communication tests.
  • The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure.

Study Questions:

Is a novel modular pacing–defibrillator system, consisting of a leadless pacemaker in wireless communication with a subcutaneous implantable cardioverter–defibrillator (ICD), able to effectively and safely provide antitachycardia and bradycardia pacing?

Methods:

MODULAR ATP was a multicenter single-group prospective study, which enrolled patients at risk for sudden death. All patients received a modular pacing–defibrillator system. Patients were followed for 6 months.

Results:

A total of 293 patients were enrolled, 162 of whom were in the 6-month endpoint cohort and 151 of whom completed the 6-month follow-up period (group sequential design–safety analysis followed by performance analysis). The percentage of patients who were free from leadless pacemaker–related major complications was 97.5%. Wireless-device communication was successful in 98.8% of communication tests. Of 151 patients, 147 (97.4%) had pacing thresholds of ≤2.0 V. The percentage of episodes of ventricular tachycardia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, eight died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure.

Conclusions:

The authors conclude that the novel leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months.

Perspective:

The advantages of a subcutaneous ICD include fewer lead-related complications and overall device-related complications are less serious, including the sequelae of infections. The safety and performance of subcutaneous ICDs are well established. Subcutaneous ICDs, however, are not able to deliver reliable and painless pacing for bradycardia or antitachycardia pacing. The development of this modular leadless pacemaker–submuscular ICD system is the natural next step to avoid the complications and harness the benefits of both subcutaneous ICD and leadless pacing. Importantly, the two components were able to communicate reliably, and not interfere with each other’s role. This is indeed a major step forward in the electrophysiology space.

Clinical Topics: Arrhythmias and Clinical EP, Implantable Devices, SCD/Ventricular Arrhythmias

Keywords: Defibrillators, Implantable, Wireless Technology


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