Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Apr 26, 2018; 10(4): 21-25
Published online Apr 26, 2018. doi: 10.4330/wjc.v10.i4.21
Outcomes after asystole events occurring during wearable defibrillator-cardioverter use
Jackson J Liang, Nicole R Bianco, Daniele Muser, Andres Enriquez, Pasquale Santangeli, Benjamin A D’Souza
Jackson J Liang, Daniele Muser, Andres Enriquez, Pasquale Santangeli, Benjamin A D’Souza, Department of Cardiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19103, United States
Nicole R Bianco, ZOLL, Pittsburgh, PA 15238, United States
Author contributions: Liang JJ, Bianco NR, and D’Souza BA designed the study, performed the analyses and wrote the initial manuscript draft; Muser D, Enriquez A and Santangeli P assisted with the writing of the manuscript and provided critical editing of the manuscript.
Institutional review board statement: The institutional review board at the University of Pennsylvania exempted this study from review.
Informed consent statement: Patients provided informed consent.
Conflict-of-interest statement: Nicole R Bianco is a research scientist at ZOLL Medical Corporation; Benjamin A D’Souza has received compensation (< $10000) for speaking for ZOLL Medical Corporation. The other authors report no conflicts of interest. The other authors report no potential conflicts of interest relevant to this article.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Benjamin A D’Souza, MD, Assistant Professor of Clinical Medicine Electrophysiology Section, Department of Cardiology, University of Pennsylvania, Perelman School of Medicine, 51 N 39th St, Philadelphia, PA 19103, United States. benjamin. d’souza@uphs.upenn.edu
Telephone: +1-215-6628000
Received: January 13, 2018
Peer-review started: January 14, 2018
First decision: February 12, 2018
Revised: March 20, 2018
Accepted: April 1, 2018
Article in press: April 1, 2018
Published online: April 26, 2018
Abstract
AIM

To examine whether wearable cardioverter defibrillator (WCD) alarms for asystole improve patient outcomes and survival.

METHODS

All asystole episodes recorded by the WCD in 2013 were retrospectively analyzed from a database of device and medical record documentation and customer call reports. Events were classified as asystole episodes if initial presenting arrhythmia was asystole (< 10 beats/minor ≥ 5 s pause). Survival was defined as recovery at the scene or arrival to a medical facility alive, or not requiring immediate medical attention. Episodes occurring in hospitals, nursing homes, or ambulances were considered to be under medical care. Serious asystole episodes were defined as resulting in unconsciousness, hospital transfer, or death.

RESULTS

Of the total 51933 patients having worn the WCD in 2013, there were 257 patients (0.5%) who had asystole episodes and comprised the study cohort. Among the 257 patients (74% male, median age 69 years), there were 264 asystole episodes. Overall patient survival was 42%. Most asystoles were considered “serious” (n = 201 in 201 patients, 76%), with a 26% survival rate. All 56 patients with “non-serious” asystole episodes survived. Being under medical care was associated with worse survival of serious asystoles. Among acute survivors, 20% later died during WCD use (a median 4 days post asystole episode). Of the 86 living patients at the end of WCD use period, 48 (56%) received ICD/pacemaker and 17 (20%) improved their condition.

CONCLUSION

Survival rates after asystole in patients with WCD are higher than historically reported survival rates. Those under medical care at time of asystole exhibited lower survival.

Keywords: Asystole, Bradycardia, Cardiac arrest, Defibrillator, LifeVest

Core tip: Survival rates after asystole, including serious episodes, in patients being treated with wearable cardioverter-defibrillators is higher than historically reported survival rates in the emergency medicine literature. Wearable cardioverter-defibrillators may improve outcomes by alarming and alerting bystanders to assist patients with asystole events.