Wearable defibrillator use in heart failure (WIF): results of a prospective registry

Andrew C Kao,Rajiv Handa,Steven W Krause,Steven J Szymkiewicz,Guillermo Reyes,Darshak Karia,Nicole R Bianco

doi:10.1186/1471-2261-12-123

Abstract

BackgroundHeart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). However, a certain percentage of patients may not be immediate candidates for ICDs, particularly those having a short duration of risk or an uncertain amount of risk. This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. The purpose of this study was to determine the incidence of SCD in this population, and the efficacy of early defibrillation by a WCD.MethodsTen enrolling centers identified 89 eligible HF patients who were either listed for cardiac transplantation, diagnosed with dilated cardiomyopathy, or receiving inotropic medications. Data collected included medical history, device records, and outcomes (including 90 day mortality).ResultsOut of 89 patients, final data on 82 patients has been collected. Patients wore the device for 75±58 days. Mean age was 56.8±13.2, and 72% were male. Most patients (98.8%) were diagnosed with dilated cardiomyopathy with a low ejection fraction (<40%) and twelve were listed for cardiac transplantation. Four patients were on inotropes. There were no sudden cardiac arrests or deaths during the study. Interestingly, 41.5% of patients were much improved after WCD use, while 34.1% went on to receive an ICD.ConclusionsIn conclusion, the WCD monitored HF patients until further assessment of risk. The leading reasons for end of WCD use were improvement in left ventricular ejection fraction (LVEF) or ICD implantation if there was no significant improvement in LVEF.

Highlights

Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD)
Sudden cardiac death (SCD) is believed to account for 40 to 70% of the mortality associated with congestive heart failure (HF), with progressive pump failure causing the majority of the remaining fatalities [1,2]
The primary purpose of the WIF registry was to determine the incidence of SCA in this population, the cause of SCA, and the efficacy of early defibrillation given by the wearable cardioverter defibrillator (WCD)

Summary

Introduction

Heart failure (HF) patients have a high risk of death, and implantable cardioverter defibrillators (ICDs) are effective in preventing sudden cardiac death (SCD). A certain percentage of patients may not be immediate candidates for ICDs, those having a short duration of risk or an uncertain amount of risk This includes the newly diagnosed patients, as well as those on the cardiac transplant list or NYHA class IV heart failure patients who do not already have an ICD. In these patients, a wearable cardioverter defibrillator (WCD) may be used until long term risk of SCD is defined. Wearable cardioverter defibrillators (WCD) such as the LifeVestW device (manufacturer: ZOLL, Pittsburgh, PA) can be used immediately to protect against SCD until longterm risk of sudden death is established or cardiac function improves. Three patient groups were followed; patients listed for heart transplantation, patients with dilated cardiomyopathy (DCM) and patients using inotropes known to cause ventricular tachyarrhythmias

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