Initial Heart Rate Score Predicts New Onset Atrial Fibrillation in Pacemaker Patients

Background Heart Rate Score (HRSc), the percent of all atrial paced and sensed event in the largest 10 bpm rate histogram bin of a pacemaker, predicts survival in patients with cardiac devices. No correlation between HRSc and development of atrial fibrillation (AF) has been reported. Objective To evaluate the relationship between pacemaker post-implantation HRSc and newly-developed AF incidence. Methods Patients with dual-chamber pacemakers, implanted 2013-2017, with ALTITIUDE remote monitoring data with ≥600,000 beats of histogram data collected at baseline were included (N=34,543). HRSc was determined from the post-implantation histogram data during the initial 3 months. Patients were excluded if they had AF, defined as atrial high-rate episodes >5 minutes or >1% of right atrial beats >170 bpm during the initial 3-months post-implantation. New AF, after the baseline period, was defined by each of the following: >1%, >10% or >25% of atrial beats >170 bpm or Atrial Tachycardia Response (ATR) events >24 hr. Results Patients were followed a median of 2.8 (1.0-4.0) years. Patients with initial HRSc≥70% were older, had higher %RA pacing, had lower %RV pacing and were more likely programmed with rate-response vs subjects with HRSc<70%. The incidence of AF increased in proportion to HRSc (Log-Rank P-value <0.001); results were insensitive to AF definition. Initial HRSc (HR:1.07, 95% CI:1.05-1.09; P<0.0001) independently predicted AF after adjusting for age, gender, % RV pacing and rate-response programming. The %RA pacing and initial HRSc correlated. Conclusion HRSc predicts subsequent AF independent of well-known risk factors in pacemaker patients. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial Current study is retrospective study. ### Funding Statement No external funding was receieved. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study, approved by the Boston Scientific Governance Board (Boston Scientific Company, Boston, USA), is a retrospective analysis of deidentified data from the LATITUDE remote monitoring cardiac implantable electronic device database. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Data and the datasets during and/or analyzed during the current study are available from the corresponding author on reasonable request.