Predictors of atrial mechanical sensing and atrioventricular synchrony with a leadless ventricular pacemaker: Results from the MARVEL 2 Study
Christophe Garweg, Surinder Kaur Khelae, Clemens Steinwender, Joseph Yat Sun Chan, Philippe Ritter, Jens Brock Johansen, Venkata Sagi, Laurence M Epstein, Jonathan P Piccini, Mario Pascual, Lluis Mont, Rik Willems, Todd Sheldon, Vincent Splett, Kurt Stromberg, Nicole Wood, Larry Chinitz, Christophe Garweg, Surinder Kaur Khelae, Clemens Steinwender, Joseph Yat Sun Chan, Philippe Ritter, Jens Brock Johansen, Venkata Sagi, Laurence M Epstein, Jonathan P Piccini, Mario Pascual, Lluis Mont, Rik Willems, Todd Sheldon, Vincent Splett, Kurt Stromberg, Nicole Wood, Larry Chinitz
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.
Copyright © 2020 The Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.
Source: PubMed