Personalized monitoring of electrical remodelling during atrial fibrillation progression via remote transmissions from implantable devices

Abstract

Aims: Atrial electrical remodelling (AER) is a transitional period associated with the progression and long-term maintenance of atrial fibrillation (AF). We aimed to study the progression of AER in individual patients with implantable devices and AF episodes.

Methods and results: Observational multicentre study (51 centres) including 4618 patients with implantable cardioverter-defibrillator +/-resynchronization therapy (ICD/CRT-D) and 352 patients (2 centres) with pacemakers (median follow-up: 3.4 years). Atrial activation rate (AAR) was quantified as the frequency of the dominant peak in the signal spectrum of AF episodes with atrial bipolar electrograms. Patients with complete progression of AER, from paroxysmal AF episodes to electrically remodelled persistent AF, were used to depict patient-specific AER slopes. A total of 34 712 AF tracings from 830 patients (87 with pacemakers) were suitable for the study. Complete progression of AER was documented in 216 patients (16 with pacemakers). Patients with persistent AF after completion of AER showed ∼30% faster AAR than patients with paroxysmal AF. The slope of AAR changes during AF progression revealed patient-specific patterns that correlated with the time-to-completion of AER (R2 = 0.85). Pacemaker patients were older than patients with ICD/CRT-Ds (78.3 vs. 67.2 year olds, respectively, P < 0.001) and had a shorter median time-to-completion of AER (24.9 vs. 93.5 days, respectively, P = 0.016). Remote transmissions in patients with ICD/CRT-D devices enabled the estimation of the time-to-completion of AER using the predicted slope of AAR changes from initiation to completion of electrical remodelling (R2 = 0.45).

Conclusion: The AF progression shows patient-specific patterns of AER, which can be estimated using available remote-monitoring technology.

Keywords: Atrial fibrillation; Atrial fibrillation progression; Electrical remodeling; Implantable cardioverter-defibrillator; Mobile health; Telemedicine; eHealth.

© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Cardiology.

Figures

Figure 1

Study flow chart. AF, atrial fibrillation; CRT-D/P, cardiac resynchronization therapy plus defibrillator/pacemaker; ICD, implantable cardioverter-defibrillator.

Figure 2

Sample signal processing and representation of the time-course of AER. (A) Schematic representation of a dual-chamber implantable cardioverter-defibrillator to obtain atrial bipolar electrograms during AF episodes. (B) Sample time-course of AAR during AF progression from early stages of AER (light green background colour) with paroxysmal AF episodes to completion of AER in persistent AF (red light background colour). (C) Sample tracings from downward arrows in B that represent different stages of AER. (D) Power spectra and DF values associated with the sample tracings in C. AAR, atrial activation rate; AER, atrial electrical remodelling; AF, atrial fibrillation; DF, dominant frequency.

Figure 3

Atrial activation rates during paroxysmal and persistent AF and associated structural changes. (A, B) Left panels show the time-course of AAR during paroxysmal and persistent AF. Right panels show sample AF tracings at downward arrows. Light green and red background colours indicate early and complete AER stages, respectively. (C) Box plots and comparisons of AAR during paroxysmal (pre-AER) and persistent AF (complete AER) between patients with ICD/CRT-D and pacemaker devices. (D) Box plots and comparison of left atrial diameters between pre-AER and complete AER stages. Box plot data show median and inter-quartile ranges. Central dots inside the box plots show the mean. AAR, atrial activation rate; AER, atrial electrical remodelling; AF, atrial fibrillation; ICD/CRT-D, implantable cardioverter-defibrillator+/−resynchronization therapy.

Figure 4

Monitoring and prediction of time-to-completion of AER. (A) Scatter-plot of AAR during paroxysmal (pre-AER stage) AF and after completion of AER in persistent AF. Each black dot represents an individual patient. The diagonal dashed line represents the line of equality. (B) Box plots and comparisons of AAR during persistent AF among patients with ICM, DCM, and other SCM. (C) Log(slope) correlation with log(time-to-completion AER). (D) Correlation of predicted and actual log(time-to-completion of AER). (E) Sample case with the predicted and actual times-to-completion of AER. (F) Box plots and comparison of time-to-completion of AER between the ICD/CRT-D and pacemaker populations. All panels, but F shows data from the ICD/CRT-D population. P25th, P50th, P75th, P100th in panels C, D indicate percentiles. AAR, atrial activation rate; AER, atrial electrical remodelling; AF, atrial fibrillation; DCM, non-ischaemic dilated cardiomyopathy; ICD/CRT-D, implantable cardioverter-defibrillator+/−resynchronization therapy; ICM, ischaemic cardiomyopathy; SCM, structural cardiomyopathies.