Authors' objectives: HTW aimed to identify and summarise evidence that addresses the following question: what is the clinical and cost effectiveness of wearable cardioverter-defibrillators (WCDs) for adults at high risk of sudden cardiac death (SCD), compared to standard care?

Authors' results and conclusions: We included two meta-analyses, two systematic reviews, one randomised controlled trial (RCT) and an additional sensitivity analysis of the RCT, two non-randomised comparative trials, three additional observational studies, and a patient focus group study. Where possible, we reported outcomes separately according to whether they included: people at high risk of SCD for a mixture of cardiac reasons, including those post-myocardial infarction with low ejection fraction; or people at high risk of SCD who had an implantable cardioverter-defibrillator (ICD) but needed it to be removed due to complications, such as infection. Based on the results of an intention-to-treat analysis in an RCT, the WCD plus standard of care significantly reduced all-cause mortality but not the primary outcome of arrhythmic-related mortality, compared to standard care alone, in people with a recent myocardial infarction and left ventricular ejection fraction less than 35%. Results of the trial from as-treated analysis and per-protocol analysis suggest there may be a significant reduction in all-cause mortality and arrhythmia-related mortality in the WCD plus standard care group versus controls, where the device is worn as recommended. Compliance was generally lower in the RCT than in the observational studies and there is some uncertainty about the level of compliance if the devices were routinely adopted. The RCT reported no significant difference in re-hospitalisation rates or number of ICD implantations between groups, and described low rates of aborted shock and high levels of successful ventricular tachycardia/ventricular fibrillation termination. The RCT reported lower rates of shortness of breath, but higher rates of itching and rash, in those treated with WCD plus standard care versus those treated only with standard care. In the RCT, four serious adverse events were described as being related or potentially related to the WCD. Inappropriate shocks were also considered by some studies as a serious adverse event, and levels of inappropriate shock were reported as being low in the RCT. A meta-analysis reported that appropriate WCD therapy was lower in the RCT group as compared with observational studies. All of the evidence for people at high risk of SCD who had an ICD but needed it to be removed, due to complications, came from single-arm observational studies. A meta-analysis of observational studies reported all-cause mortality rates, appropriate shocks/therapy, and inappropriate shocks/therapy in the ICD-explant population and the non-ICD explant population. The meta-analysis reported that pooled incidence rates for each of the outcomes did not vary significantly between indications. Quality of life and patient-reported outcomes showed some improvement for both the population awaiting further intervention and those after ICD explant. HTW developed a cost-utility analysis, which showed that discharge home with a WCD was more effective but more costly than discharge home without WCD in adults at high risk of SCD due to a recent myocardial infarction (it was not cost effective). In people with an explanted ICD, discharge home with WCD was found to be as effective as inpatient monitoring and less costly. Therefore, WCD was cost effective in this patient group.

Authors' methods: The Evidence Appraisal Report is based on a literature search (strategy available on request) for published clinical and economic evidence on the health technology of interest. It is not a full systematic review but aims to identify the best available evidence on the health technology of interest. Researchers critically evaluate and synthesise this evidence. We include the following clinical evidence in order of priority: systematic reviews; randomised trials; non-randomised trials. We only include evidence for “lower priority” evidence where outcomes are not reported by a “higher priority” source. We also search for economic evaluations or original research that can form the basis of an assessment of costs/cost comparison. We carry out various levels of economic evaluation, according to the evidence that is available to inform this.

Project Status: Completed

URL for project: https://healthtechnology.wales/reports-guidance/wearable-cardioverter-defibrillators/

Year Published: 2022

URL for published report: https://healthtechnology.wales/reports-guidance/wearable-cardioverter-defibrillators/

English language abstract: An English language summary is available

Publication Type: Rapid Review

Country: Wales, United Kingdom

Organisation Name: Health Technology Wales

Contact Address: Floor 3, 2 Capital Quarter, Tyndall Street, Cardiff, CF10 4BZ

Contact Name: Susan Myles, PhD

Contact Email: healthtechnology@wales.nhs.uk