Predictors of atrial mechanical sensing and atrioventricular synchrony with a leadless ventricular pacemaker: Results from the MARVEL 2 Study

Heart Rhythm. 2020 Dec;17(12):2037-2045. doi: 10.1016/j.hrthm.2020.07.024. Epub 2020 Jul 24.

Abstract

Background: The MARVEL (Micra Atrial TRacking Using a Ventricular AccELerometer) 2 study assessed the efficacy of atrioventricular (AV) synchronous pacing with a Micra leadless pacemaker. Average atrioventricular synchrony (AVS) was 89.2%. Previously, low amplitude of the Micra-sensed atrial signal (A4) was observed to be a factor of low AVS.

Objective: The purpose of this study was to identify predictors of A4 amplitude and high AVS.

Methods: We analyzed 64 patients enrolled in MARVEL 2 who had visible P waves on electrocardiogram for assessing A4 amplitude and 40 patients with third-degree AV block for assessing AVS at rest. High AVS was defined as >90% correct atrial-triggered ventricular pacing. The association between clinical factors and echocardiographic parameters with A4 amplitude was investigated using a multivariable model with lasso variable selection. Variables associated with A4 amplitude together with premature ventricular contraction burden, sinus rate, and sinus rate variability (standard deviation of successive differences of P-P intervals [SDSD]) were assessed for association with AVS.

Results: In univariate analysis, low A4 amplitude was inversely related to atrial function assessed by E/A ratio and e'/a' ratio, and was directly related to atrial contraction excursion (ACE) and atrial strain (Ɛa) on echocardiography (all P ≤.05). The multivariable lasso regression model found coronary artery bypass graft history, E/A ratio, ACE, and Ɛa were associated with low A4 amplitude. E/A ratio and SDSD were multivariable predictors of high AVS, with >90% probability if E/A <0.94 and SDSD <5 bpm.

Conclusion: Clinical parameters and echocardiographic markers of atrial function are associated with A4 signal amplitude. High AVS can be predicted by E/A ratio <0.94 and low sinus rate variability at rest.

Trial registration: ClinicalTrials.gov NCT03752151.

Keywords: Atrioventricular block; Atrioventricular synchrony; Leadless pacing; Micra transcatheter pacemaker; Predictors.

Publication types

  • Clinical Trial
  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Atrioventricular Block / diagnosis
  • Atrioventricular Block / physiopathology
  • Atrioventricular Block / therapy*
  • Cardiac Pacing, Artificial / methods*
  • Echocardiography
  • Electrocardiography
  • Female
  • Follow-Up Studies
  • Heart Atria / physiopathology
  • Heart Ventricles / physiopathology*
  • Humans
  • Male
  • Middle Aged
  • Pacemaker, Artificial*
  • Prospective Studies
  • Young Adult

Associated data

  • ClinicalTrials.gov/NCT03752151