Wearable cardioverter defibrillator for transient arrhythmic risk and sudden cardiac death prevention: a systematic review and updated meta-analysis.

backgroundSudden cardiac death (SCD) is a common cause of cardiovascular mortality, often triggered by ventricular arrhythmias in the setting of myocardial vulnerability. The wearable cardioverter-defibrillator (WCD) offers temporary protection against SCD, particularly when an implantable device is contraindicated or premature.

objectivesWe conducted a comprehensive meta-analysis to assess the effectiveness of the WCD in appropriately terminating life-threatening arrhythmias such as sustained ventricular tachycardia (VT) and ventricular fibrillation (VF), preventing sudden cardiac death.

methodsFollowing Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically reviewed 40 studies comprising 59 647 adults fitted with a WCD for primary or secondary SCD prevention. Random-effects meta-analysis, subgroup analysis, meta-regression and sensitivity analyses were performed.

resultsThe pooled incidence of appropriate WCD intervention was 3% (95% CI 2% to 3%), with substantial heterogeneity (I²=88.9%). The prediction interval ranged from 1% to 8%, indicating that future studies conducted in selected high-risk populations may observe significantly higher WCD intervention. Life-threatening arrhythmias were higher during early follow-up (≤60 days). An appropriate daily WCD wearing time significantly influenced the results. Gender, age, ejection fraction and study design were not significant modifiers. No publication bias was detected.

conclusionsThe WCD represents an effective strategy for preventing SCD in early high-risk settings, with its benefit closely linked to adherence and appropriate patient selection.