Abstract 15246: Myocardial Deformation for Prediction of Major Arrhythmic Events in Patients With Non-Ischemic Cardiomyopathy and Primary Prevention Implantable Cardioverter Defibrillators

Introduction: Sudden cardiac death is a major cause of mortality in patients with non-ischemic cardiomyopathy (NICM). Implantable cardioverter-defibrillator (ICD) is an established prophylactic measure. But, optimal identification of patients with greatest likelihood of benefiting poses ongoing challenges.

Objective: To assess the prognostic value of myocardial deformation for predicting ICD intervention while accounting for competing mortality risk.

Methods: 180 NICM patients eligible for primary prevention ICD underwent cardiac magnetic resonance (CMR). Myocardial strains (left ventricular radial, circumferential, longitudinal; left atrial; and right ventricular free wall longitudinal strain (RV GLS)) were measured via CVI42 feature tracking. In a multivariable Fine-Gray competing risk model, incremental values of strains were assessed, adding to a baseline model based on clinical features and late gadolinium enhancement (LGE). The primary endpoint was ventricular tachycardia/fibrillation treated with ICD intervention, including shocks or anti-tachycardia pacing.

Results: 159 patients with ICD (117 male; 54 ± 13 years) were included for final analysis (follow-up: 1176±960 days; median: 896). 26 patients met the primary endpoint. RV GLS showed a statistically significant difference between patients with and without events (-12.5% ± 5 vs -16.4% ± 5.5, p = 0.001). Univariate analyses revealed that LGE and RV GLS were significantly associated with outcome, even after accounting for competing risk (LGE: HR=3.69, 95% CI=1.28-10.62; RV GLS: HR=2.04, 95% CI=1.30-3.22). Adding RV GLS to the baseline model improved its prognostic value, with a c statistic improvement from 0.678 to 0.730. RV GLS hazard ratio remained significant in multivariate analysis after accounting for competing risk (HR=1.73, 95% CI=1.12-2.66) (Table 1).

Conclusions: In NICM, RV GLS provides additional predictive value above LGE and clinical features for ICD intervention.