The wearable cardioverter defibrillator (WCD) is the first wearable defibrillator (LifeVestTM), and is manufactured by the Zoll Medical Corporation (Pittsburg, Pennsylvania). The device was FDA approved in 2001 and is currently available in the United States, Europe, Japan, and several other countries.
The WCD is worn outside the body and continuously monitors the patient’s heart with dry, nonadhesive sensing electrodes to detect life-threatening abnormal heart rhythms.1 If a life-threatening rhythm is detected, the device alerts the patient prior to delivering a shock, allowing a conscious patient to delay treatment. If the patient becomes unconscious, the device releases a Blue™ gel and then delivers an electrical shock to restore normal rhythm.
Indications for WCDs
The WCD is worn by patients at risk for sudden cardiac death (SCD) and is noninvasive therapy used in place of an implantable cardiac defibrillator (ICD) for patients with a transient condition or for patients who temporarily cannot be implanted. Generally, a WCD is a bridge between an acute event and an ICD or until ejection fraction improves.2, 3
Indications for appropriate use of the WCD include the following:
- post-ICD explant (i.e. infection and recalls, replacements, or errors)
- ventricular tachycardia (VT) or ventricular fibrillation (VF) while awaiting ICD
- genetic predisposition to SCD
- left ventricle ejection fraction (LVEF) ≤ 35 percent with unspecified cardiomyopathy2, 5
Nontraditional ICD indications include the following:
- recent myocardial infarction
- post-coronary bypass grafting (CABG) or percutaneous coronary intervention
- recent nonischemic cardiomyopathy
- miscellaneous or unknown indications
Moving from WCD to ICD
The decision to continue WCD use or to implant an ICD after an event is based on the reassessment of ejection fraction, the occurrence of arrhythmias, and clinical status between 30 and 90 days. Timely follow-up and regular evaluation of patients is important to monitor correction of heart function during WCD use.
If an ICD is indicated, implantation is preferable and more effective than a WCD because patient compliance—an issue with WCDs—is irrelevant to therapy with ICDs.4 Patients who would benefit from an ICD should proceed with implantation and terminate the use of a WCD. Not all patients require use of the WCD for a full 90 days.
Not all patients require an ICD. The proportion of WCD patients who get an ICD range from 36 to 46 percent. Most patients never receive an ICD and no longer require use of a WCD after improved function. When ICDs were not used—41 percent of the time—the reason was due to improvement in the patient’s transient condition.4,6
Over-deployment of WCDs
Typically, the WCD is prescribed and authorized for 90-day periods and billed to insurance companies in 30-day claim increments. HealthHelp, a coordinated-care management company that works with payers to reduce costs while improving the quality of plan-member care, changed its WCD-prescription review process in 2015.
HealthHelp’s review process has moved to a 30-day WCD term, with an authorization review every 30 days due to compliance issues with the device. HealthHelp’s current evidence-based guidelines for indications and appropriate length of use for WCDs are as follows:
- Post Cardiac Intervention (Percutaneous Coronary Intervention or CABG): 90 days
- Cardiomyopathy, Ischemic with Ventricular Fibrillation/Tachycardia (VF/VT): 90 days
- Cardiomyopathy, Non-Ischemic Dilated (NIDCM): 90 days
- Cardiomyopathy, Ischemic Type without Ventricular Fibrillation/Tachycardia: 60 days
- Cardiac Rhythm or Cardiac Arrest: 60 days
- ICD Failure or Local Infection and Re-Implantation after waiting: 60 days
- Myocardial Infarction, Recent Event: 60 days
- High Risk of Sudden Cardiac Death: 30 days
Challenges with WCD Compliance
The results of the post-FDA approval national registry showed the overall compliance with wearing a WCD was 90 percent of the time for only 52 percent of patients.2
Further, 40 percent of patients in the registry used the WCD for 30 days or less with an overall median length of use equal to 36 days. In two different studies, 14.2 percent and 24.5 percent of patients stopped wearing the WCD because of comfort issues or adverse reactions.2, 3
Also, patients might not be compliant with WCD because of the 1 to 2 percent risk of receiving inappropriate shocks that can be painful.2-4
Best Practices in WCD Benefit Management
Determining how long a WCD needs to be used depends on compliance, the indication and nature of transient conditions, and scheduled reassessment of left ventricular ejection fraction. HealthHelp engages in this process, improving timely and appropriate care to members while reducing unnecessary WCD use.
² Mina K.Chung MK, Szymkiewicz SJ, Shao M, Zishiri E, Niebauer M, Lindsay BD, Tchou PJ. Aggregate National Experience with the Wearable Cardioverter-Defibrillator: Event Rates, Compliance, and Survival. Journal of the American College of Cardiology. 2010; 56(3):194-203.
³ Feldman MA, Klein H, Tchou PJ, Murali S, Hall WJ, Mancini D, Boehmer J, Harvery M, Heilman MS, Szymkiewicz SJ, Moss AJ. Use of a Wearable Defibrillator in Terminating Tachyarrhythmias in Patients at High Risk for Sudden Death: Results of WEARIT/BIROAD. Pacing and Clinical Electrophysiology. 2004; 27(1):4–9.
4 Kutyifa V, Moss AJ, Klein H, Biton Y, McNitt S, MacKecknie B, Zareba W, Goldenberg I. Use of the Wearable Cardioverter Defibrillator in High-Risk Cardiac Patients; Data from the Prospective Registry of Patients Using the Wearable Cardioverter Defibrillator (WEARIT-II Registry). Circulation. 2015; 132:1613-1619.
5 Epstein AE, Dimarco JP, Ellenbogen KA, Estes NA 3rd., Freedman RA, Gettes LS, Gillinov AM, Gregoratos G, Hammill SC, Hayes DL, Hlatky MA, Newby LK, Page RL, Schoenfeld MH, Silka MJ, Stevenson LW, Sweeney MO. American College of Cardiology; American Heart Association Task Force on Practice Guidelines; American Association for Thoracic Surgery; Society of Thoracic Surgeons. ACC/AHA/HRS 2008 Guidelines for device-based therapy of cardiac rhythm abnormalities. Journal of the American College of Cardiology. 2008; 51(21):e1–e62.
6 Steinbeck G, Andresen D, Seidl K, Brachmann J, Hoffmann E, Wojciechowski D, Kornacewicz JZ, Sredniava B, Lupkovics G, Hofgartner F, Lubinski A, Rosenquist M, Habets A, Wegscheider K, Senges J. Defibrillator Implantation Early After Myocardial Infarction. New England Journal of Medicine. 2009; 361:1427-1436.