Abstract 4370453: Incidence and Predictors of Shock in Patients with Noncompaction Cardiomyopathy and Implantable Cardioverter-Defibrillators: A Multicenter Retrospective Study.

Background: Noncompaction cardiomyopathy (NCCM) is a distinct myocardial disorder associated with a high risk of ventricular arrhythmias and sudden cardiac death. Although implantable cardioverter-defibrillators (ICDs) are frequently used in this population, data on predictors of shock therapy remain limited. Aim: Evaluation of a large cohort of patients with NCCM and ICDs to identify incidence and clinical factors associated with ICD shock Methods: This retrospective cohort study included patients with confirmed NCCM between 2002 and 2023 at all Mayo Clinic sites. Baseline clinical data, genetic findings, cardiac imaging parameters, and device-related outcomes were collected through detailed chart review. Multivariable Logistic regression was used to identify independent predictors. Results: Among 145 patients with NCCM who received ICDs, the median age was 45 years (IQR: 34–56), with 75 (52%) female and 120 (83%) White. The median left ventricular ejection fraction (LVEF) was 35% (IQR: 22.5–47.5%), and the median follow-up from ICD implantation was 6.4 years (IQR: 2.9–11.0). Most ICDs (124, 85.5%) were implanted for primary prevention. Appropriate shocks were observed in 37 patients (25.5%), with 14 (9.8%) experiencing three or more appropriate shocks. Inappropriate shocks occurred in 15 patients (10.3%). Device-related complications were reported in 22 patients (15.2%), including infections in 4 (2.8%), lead fractures or dislodgement in 17 (11.9%), and pneumothorax in 1 (0.7%). Clinical predictors of shocks are illustrated in the figure. Conclusion: ICD therapy for NCCM patients prevented SCD in 25.5% of patients. Syncope, RBBB, troponin T >30 ng/L, and imaging-based apical trabeculations were independently associated with ICD shocks in patients with NCCM. These factors may aid in risk stratification and clinical decision-making.