Wearable cardioverter-defibrillator (WCD) therapy as prevention of sudden cardiac death in patients at risk - Update 2018

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Research area: High tech medicine

Project team: Gregor Goetz

Project leaders: Tom Jefferson, Claudia Wild
Project team: Emilio Chiarolla, Massimiliano Orso, Gregor Goetz, Michal Stanak

This project will be conducted collaboratively with the Italian National Agency for Regional Health Services (AGENAS).

Duration: July 2018 – November 2018
Suggested by: Representatives of federal states in Austria
Language: English (Executive summary in German)
Publication: Decision Support Document No. 103/Update 2018: https://eprints.aihta.at/1186

Background:
Sudden cardiac death is the most common cause of death in patients with coronary artery disease. In most cases, ventricular tachyarrhythmias (ventricular tachycardia/VT and ventricular fibrillation/VF) are the underlying etiology of sudden cardiac death. These arrhythmias can be treated by rapid counter-shock performed by implantable or external/wearable defibrillators or by a counter-beat by a pacemaker. Other causes of sudden cardiac death are bradycardia or torsades de pointes. According to guidelines (e.g., from the American Heart Association), there is a recommended waiting time in some situations before an implantable cardioverter-defibrillator (ICD) is indicated. A recovery of structural abnormality and an improvement of ventricular dysfunction could occur so that an ICD therapy may not be indicated anymore. Furthermore, a patient could have some contraindications (e.g., an infection) and therefore should not receive an ICD for some time, or an ICD needs to be (temporarily) explanted due to specific reasons. Thus, a wearable cardioverter defibrillator (WCD) may be used as a bridge to an ICD or to a heart transplant (in order to cover the waiting period).

In 2016, the LBI-HTA conducted a systematic review regarding the effectiveness and safety of the WCD for specific indications. The HTA-report was a „collaborative assessment“ within the EU-project EUnetHTA. In 2018, the Spanish HTA-organisation named Avalia-t conducted an update-assessment. Both reports highlighted the lack of sound scientific evidence and concluded that results from randomised controlled trials (RCTs) are necessary to prove the (comparative) effectiveness and safety of the device in a solid manner.

Due to ongoing research in the field of the WCD and the prospect of upcoming results from a previously conducted RCT, another collaborative HTA-report will be performed in 2018: The Italian National Agency for Regional Health Services (AGENAS) will – in collaboration with the LBI-HTA – conduct a systematic review on the efficacy and safety of the WCD.

Aims of the project:

The project aims at performing an evidence synthesis based on a systematic literature search regarding the effectiveness and safety of the WCD for specific indications.

Research Question:

  1. What is the evidence that the use of a WCD as a temporary measure for the treatment of patients at risk of sudden cardiac death is more effective and safe than hospital observation with regard to the defined outcomes (see PICO)?
  2. Which (health-related) influences (if any) does the WCD have on Quality of Life of patients?
  3. What is the satisfaction and compliance rate of patients with the WCD?

Methods:

  • A systematic review of published clinical studies/documents regarding WCD (LifeVest) in comparison to the control determined in the PICO question
  • Systematic literature search in:
    • Cochrane (CENTRAL), Embase, Medline, PubMed, PsycINFO.
    • Handsearch (in references), internet-search, contacting manufacturers
  • Study selection: Two review authors (MO, GG) screened the abstracts independently and evaluated their eligibility to be included in the assessment. In case of disagreement, a third researcher will be consulted (TJ).
  • Critical appraisal (=risk of bias assessment) will be conducted by two researchers (GG, MO).
  • Data extraction: One researcher (MO) extracts the data and another one (GG) controls the extracted data.
  • Assessing the strength of evidence: Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach is used.
  • Use of the EUnetHTA „HTA Core Model“ as well as EUnetHTA guidelines

PICO-question:

Description

Project scope

Population

Population: adults over 18 years of age (according to CE mark) with the following indications:

  1. As a temporary intervention prior to the insertion of an ICD for:
    1. patients immediately after explantation of an ICD, if an immediate reimplantation of an ICD is not possible;
    2. patients in whom an immediate implantation of an ICD is indicated, but not possible due to temporary contraindications.
  2. As a temporary measure prior to optimal pharmacological therapy, or as a protection during pharmacological therapy optimisation when a heightened risk of SCD is present, but possibly resolvable over time or with treatment of left ventricular dysfunction; for patients with:
    1. ischaemic heart disease with envisaged or recent revascularization (90-day waiting period post revascularization with either CABG or PCI);
    2. secondary cardiomyopathy (tachycardia mediated, thyroid mediated, etc.) or induced arrhythmias (secondary to hypothermia, electrolyte imbalance, iatrogenic prolongation of the QT interval, etc.) in which the underlying cause is potentially treatable;
    3. with certain forms of structural heart disease associated with risk of malignant arrhythmias or primary electric diseases, prior to diagnostic tests such as MRI.
  3. Post Myocardial Infarction (MI) and LVEF of ? 35%, as a temporary measure during prognostic stratification in situations associated with increased risk of arrhythmic death within 40 d of MI
  4. As a temporary measure prior to heart transplantion in patients without ICD

Intervention

WCD/LifeVest® (WCD 4000), from ZOLL (Lifecor) Medical Corporation, Pittsburgh, PA, USA.

Comparator

Hospital observation

Outcomes

Effectiveness:

Primary endpoint:

  • Mortality:
    • All-cause mortality,
    • Disease-specific mortality.

 

Secondary endpoints:

  • Avoidance of ICD implantation,
  • HRQoL,
  • Hospitalisation rate,
  • Satisfaction,
  • Compliance.

Safety:

  • AEs, device related and patient related (frequency of AEs, what are these, frequency of discontinuation due to AEs, frequency of unexpected AEs),
  • SAEs, device related and patient related (frequency of SAEs, what are

these, frequency of SAEs leading to death).

Study designs

Effectiveness: Randomised controlled trials (RCTs), prospective non-randomised controlled trials

 

Safety: Randomised controlled trials (RCTs), prospective non-randomised controlled trials, prospective case series studies and prospective register data.

 

Patients aspects: qualitative studies (according to the EUnetHTA Core Model® 3.0)

 

Schedule/ milestones (in months):

Time frame

Task

July 2018

Scoping, precision of PICO-question collaboratively with AGENAS

August-September 2018

Systematic literature search, non-systematic hand search, literature selection

September-October 2018

Data extraction, synthesis, and assessment of evidence, drafting of 1st version of HTA-report

November 2016

Internal/external review, formatting, preparation of final version of HTA-report, publication