Heart. 2026 Mar 9:heartjnl-2025-326956. doi: 10.1136/heartjnl-2025-326956. Online ahead of print.
ABSTRACT
BACKGROUND: Optimisation of medical therapy is recommended for patients with newly diagnosed non-ischaemic cardiomyopathies (NICM) before consideration of a primary preventive implantable cardioverter-defibrillator (ICD). During this optimisation period, patients face a potentially elevated risk for sudden cardiac death (SCD) that can be countered with a wearable cardioverter-defibrillator (WCD). This systematic review aims to assess the risk for SCD in patients with newly diagnosed NICM.
METHODS: A systematic review was performed in Medline, Embase and Cochrane Library last updated on March 2025. Studies with patients aged ≥18 years with newly diagnosed NICM (≤90 days) who were recipients of WCD were included. Study selection, study quality assessment and data extraction were performed by two reviewers independently. Data on percentage of patients with appropriate WCD shocks (as proxy for sustained ventricular arrhythmia, potentially leading to SCD), inappropriate WCD shocks and device implantation were pooled by random-effects model.
RESULTS: 50 non-controlled observational studies were included, comprising a total of 10 066 patients with NICM. The percentage of appropriate shocks was 1% (87/7708; 95% CI 1% to 2%) in patients with NICM, 2% (16/1049; 95% CI 1% to 2%) in patients with myocarditis, 3% (7/183; 95% CI 0% to 20%) in peripartum cardiomyopathy, 2% (2/102; 95% CI 0% to 7%) in Takotsubo syndrome and 1% (8/594; 95% CI 1% to 3%) for congenital/inherited or genetic cardiomyopathy. Inappropriate shocks ranged from 0% to 1%. At the end of follow-up, between 6% (Takotsubo syndrome) and 43% (congenital/inherited or genetic cardiomyopathy) of patients received an ICD.
CONCLUSION: Patients with NICM face a significant risk of SCD during the drug optimisation period before deciding if they qualify for ICD implantation. Results of this meta-analysis are based on non-comparative studies; however, the assessment of an appropriate shock delivered and recorded by the WCD is highly reliable.
PROSPERO REGISTRATION NUMBER: CRD42024555879.
PMID:41802849 | DOI:10.1136/heartjnl-2025-326956