Author + information
- Received January 2, 2020
- Revision received March 30, 2020
- Accepted April 17, 2020
- Published online September 21, 2020.
- Michael R. Rehorn, MD, MS∗,
- Rahul S. Loungani, MD∗,
- Eric Black-Maier, MD,
- Amanda C. Coniglio, MD,
- Ravi Karra, MD, MHS,
- Sean D. Pokorney, MD, MBA and
- Michel G. Khouri, MD∗ ()
- ↵∗Address for correspondence:
Dr. Michel G. Khouri, Division of Cardiology, Duke University Hospital, 40 Duke Medicine Circle, Room 3347, Orange Zone, Durham, North Carolina 27710.
Objectives This study characterized the relationship between conduction disease and cardiac amyloidosis (CA) through longitudinal analysis of cardiac implantable electronic device (CIED) data.
Background Bradyarrhythmias and tachyarrhythmias are commonly reported in CA and may precede a CA diagnosis, although the natural history of conduction disease in CA is not well-described.
Methods Patients with CA (transthyretin amyloidosis cardiomyopathy [ATTR-CM] and light-chain amyloidosis [AL-CA]) and a CIED were identified within the Duke University Health System. Patient characteristics at the time of implantation, including demographics and data relevant to CA diagnosis, cardiac imaging, and CIED were recorded. CIED interrogations were analyzed for pacing and atrial fibrillation (AF) burden, activity level, lead parameters, and ventricular arrhythmia incidence and/or therapy.
Results Thirty-four patients with CA (7 with AL-CA, 27 with ATTR-CM [78% with wild-type]; 82% men) with median age of 75 years and a mean ejection fraction of 42 ± 13% had a CIED implanted for bradycardia (65%) or prevention of sudden cardiac death (35%). CIED implantation preceded CA diagnosis in 14 patients (41%). Over a mean follow-up of 3.1 ± 4.0 years, right ventricular sensing amplitudes decreased but did not result in device malfunction; lead impedances and capture thresholds remained stable. Between post-implantation years 1 and 5, mean ventricular pacing increased from 56 ± 9% to 96 ± 1% (p = 0.003) and AF burden increased from 2 ± 1.3 to 17 ± 3 h/day (p = 0.0002). Ventricular arrhythmias were common (mean episodes per patient per year: 6.7 ± 2.3 [ATTR-CM] and 5.1 ± 3.2 [AL-CA]) but predominately nonsustained; only 1 patient with AL-CA required implantable cardioverter-defibrillator therapy.
Conclusions Longitudinal analysis of CIED data in patients with CA revealed progressive conduction disease, with high AF burden and eventual dependence on ventricular pacing, although lead parameters remained stable. Ventricular arrhythmias were common but predominantly nonsustained, particularly in ATTR-CM.
↵∗ Drs. Rehorn and Loungani contributed equally to this paper and are joint first authors.
Drs. Rehorn and Loungani have received research support from Pfizer. Dr. Karra has received consulting/advisory board support from Intellia Therapeutics and Alnylam Pharmaceuticals; and has been a member of Alnylam Pharmaceuticals Speakers Bureau. Dr. Pokorney has received research support from Bristol-Myers Squibb, Pfizer, Janssen Pharmaceuticals, the U.S. Food and Drug Administration, Gilead, and Boston Scientific; has received consulting/advisory board support from Medtronic, Boston Scientific, Philips, Janssen Pharmaceuticals, Bristol-Myers Squibb, Pfizer, and Portola; and has received Data Safety Monitoring Board support from Medpace. Dr. Khouri has received research support from Pfizer; has received consulting/advisory board support from Pfizer and Alnylam Pharmaceuticals; and has been a Speakers Bureau member of Alnylam Pharmaceuticals.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Clinical Electrophysiology author instructions page.
- Received January 2, 2020.
- Revision received March 30, 2020.
- Accepted April 17, 2020.
- 2020 American College of Cardiology Foundation
This article requires a subscription or purchase to view the full text. If you are a subscriber or member, click Login or the Subscribe link (top menu above) to access this article.