Association of cardiac implantable electronic devices with survival in bifascicular block and prolonged PR interval on electrocardiogram

Naeem Moulki, Jessica V. Kealhofer, David G. Benditt, Amy Gravely, Kairav Vakil, Santiago Garcia, Selcuk Adabag

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


Purpose: Bifascicular block and prolonged PR interval on the electrocardiogram (ECG) have been associated with complete heart block and sudden cardiac death. We sought to determine if cardiac implantable electronic devices (CIED) improve survival in these patients. Methods: We assessed survival in relation to CIED status among 636 consecutive patients with bifascicular block and prolonged PR interval on the ECG. In survival analyses, CIED was considered as a time-varying covariate. Results: Average age was 76 ± 9 years, and 99% of the patients were men. A total of 167 (26%) underwent CIED (127 pacemaker only) implantation at baseline (n = 23) or during follow-up (n = 144). During 5.4 ± 3.8 years of follow-up, 83 (13%) patients developed complete or high-degree atrioventricular block and 375 (59%) died. Patients with a CIED had a longer survival compared to those without a CIED in the traditional, static analysis (log-rank p < 0.0001) but not when CIED was considered as a time-varying covariate (log-rank p = 0.76). In the multivariable model, patients with a CIED had a 34% lower risk of death (hazard ratio 0.66, 95% confidence interval 0.52–0.83; p = 0.001) than those without CIED in the traditional analysis but not in the time-varying covariate analysis (hazard ratio 1.05, 95% confidence interval 0.79–1.38; p = 0.76). Results did not change in the subgroup with a pacemaker only. Conclusions: Bifascicular block and prolonged PR interval on ECG are associated with a high incidence of complete atrioventricular block and mortality. However, CIED implantation does not have a significant influence on survival when time-varying nature of CIED implantation is considered.

Original languageEnglish (US)
Pages (from-to)335-341
Number of pages7
JournalJournal of Interventional Cardiac Electrophysiology
Issue number3
StatePublished - Aug 1 2018

Bibliographical note

Funding Information:
We acknowledge Carl (Marty) Young, RN, for his assistance in obtaining the ECGs and Lisa Langsetmo, PhD, for her consultation in statistical analysis. This manuscript is the result of work supported with resources and use of facilities of the Minneapolis Veterans Affairs Health Care System. Dr. Benditt is a consultant for and holds equity in Medtronic Inc. and St. Jude Medical. In addition, Dr. Benditt is supported in part by a grant from the Dr. Earl E. Bakken family in support of Heart-Brain research. Dr. Adabag has received research funding from the American Heart Association and Medtronic. The other authors declare that they have no conflict of interest.

Publisher Copyright:
© 2018, Springer Science+Business Media, LLC, part of Springer Nature.


  • Atrioventricular block
  • Bifascicular block
  • Cardiac implantable electronic device
  • Pacemaker
  • Survival


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