A Predictive Model for the Long-Term Electrical Performance of a Leadless Transcatheter Pacemaker

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• The Micra leadless pacemaker offers an alternative to transvenous leads, but metrics for predicting its long-term electrical performance are needed.
• Lack of predictive metrics hinders optimal procedural decision-making for leadless pacing.

Purpose of the Study:

• To develop a predictive model for the long-term electrical performance of the Micra leadless pacemaker.
• Identify key patient and device characteristics that predict elevated pacing thresholds at 12 months post-implantation.

Main Methods:

• Analysis of 1,843 patients with 1-year post-implantation data from Micra studies.
• Defined elevated pacing capture threshold (PCT) as ≥2.0 V at 0.24 ms, an increase of ≥1.5 V, or system revision due to high thresholds.
• Evaluated univariate and multivariate associations between baseline characteristics and elevated PCT at 12 months.

Main Results:

• 4.1% of patients (75/1,843) experienced elevated thresholds at 12 months, with 13 requiring system revisions.
• Univariate predictors included implantation impedance, PCT, male sex, diabetes, and ischemic cardiomyopathy.
• Multivariable analysis identified male sex, diabetes history, implantation PCT ≥2 V, and impedance <800 Ω as independent predictors (p < 0.05).

Conclusions:

• Male sex, diabetes, elevated implantation pacing capture threshold, and low impedance are independent predictors of elevated thresholds at 12 months.
• These findings provide a foundation for a tool to assist in procedural decision-making for Micra leadless pacemaker implantation.