Wearable cardioverter defibrillator (WCD)-Indications and use Recommendations of the working group 1 of the German Cardiac Society (DGK)

The wearable cardioverter defibrillator (WCD, defibrillator vest) is a temporary, noninvasive option for rhythm detection and treatment in patients with an increased risk for the occurrence of life-threatening ventricular tachyarrhythmia (VA) or sudden cardiac death (SCD). The aim of this position paper is to assses indications for WCD based on current data. The WCD is an effective measure for prevention of SCD caused by persistent VA. The spectrum of indications for WCD can be divided into two parts: 1) patients with temporary high-grade functional disorder of the left ventricle until recovery of left ventricular function or a decision for or against a permanent implantable cardioverter defibrillator (ICD). The WCD can help in monitoring patients with respect to VA and to prevent SCD in the time period up to re-evaluation of the indications for a definitive ICD. 2) Patients with established indications for an ICD with temporary contraindications for implantation. Current studies and registry data confirm the effectiveness of WCD in the termination of persistent VA. A high degree of safety without relevant recognizable risks (inadequate shock rate <1%) could be documented. The recently published randomized VEST study showed no advantage of WCD with respect to prevention of SCD, albeit with low treatment adherence. In large published patient cohorts the incidence of VA in need of treatment of the WCD is low (<3% within 3 months), particularly in postinfarction patients with high-grade limited left ventricular function. Based on current data the decision for WCD treatment must be made individually. The risk-benefit analysis in individual case may have advantage for WCD especially when considering the neglectable risk of WCD therapy. Therefore, based on individual considerations by the treating consultant in justified cases with an expected high temporary risk of SCD due to VA, a WCD can be used when the patient is a candidate for a permanent ICD after successful re-evaluation. Education of patients and relatives plays a central role. A WCD should only be used when continuous wearing can be achieved. Monitoring of treatment adherence should be carried out using remote monitoring (LifeVest network).