In January 2019, the Austrian HTA body Ludwig-Boltzmann Institute (LBI) has published the update of their decision support document (DSD) 103, which concerns the wearable cardioverter-defibrillator (WCD) therapy in primary and secondary prevention of sudden cardiac arrest in patients at risk.
The project aimed at synthesizing the currently available evidence regarding the use of the WCD, in order to make sure that their previous assessment, done in collaboration with Italian AGENAS, was up to date. A systematic review regarding the effectiveness and safety of the WCD was performed. The systematic literature search was conducted on Cochrane (CENTRAL), Embase and Medline. The EUnetHTA Core Model © was used for the reporting. The methodological quality of the trials was assessed by the IHE-20 checklist for case series and the Cochrane Risk of Bias Tool for RCTs. In addition, the strength of the evidence was evaluated using the GRADE method.
Eventually, 11 eligible studies were identified: an RCT for the assessment of effectiveness and 10 observational studies for the evaluation of safety. The comparators of WCD was the pharmacological therapy alone.
- The scientific evidence from the RCT indicates the WCD in combination with guideline-directed medical therapy (GDMT) is not proven to be more effective than GDMT alone based on the arrhythmic mortality endpoint (1.6% in the intervention group (n=1,524) v 2.5% in the control group (n=778), p=0.18). In all-cause mortality, a statistically significant difference was found between the intervention group (WCD + GDMT) and the control group (GDT alone): 3.1% vs. 4.9% (p = 0.04). However, there is an increased risk that this result will be a random finding because no correction has been made for multiple testing
- No statistically significant difference was identified at other (secondary) endpoints between the two groups: Incidence of ventricular tachycardia / ventricular fibrillation (1.6% v 2.6%, p=0.1), hospitalization rate (31.2% v 32.5%, p = 0.51)
- On average, the WCD was worn 14 hours per day (median = 18 hours per day)
- The studies included in the evaluation of the safety of the device suggest that the WCD could be a relatively safe device. The safety was assessed based on adverse events (rash, false alarms, dizziness, fainting, palpitations, and comfort and lifestyle-related impairments)
The authors conclude that the comparative effectiveness of the WCD could not be established and that it is unclear if and especially for whom the plausible theoretical advantages of using the WCD can be translated into clinically relevant benefits. The authors state that further research is necessary for the development of solid conclusions.
See full details in German here.
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