Abstract
OBJECTIVES: To assess the left ventricular remodeling index (LVRI) for predicting ventricular tachyarrhythmia (VTA) in patients with dilated cardiomyopathy (DCM) with left ventricular ejection fraction (LVEF) < 35%. MATERIALS AND METHODS: In this retrospective single-center study, consecutive DCM patients with LVEF < 35% (n = 271) who underwent cardiac magnetic resonance (CMR) imaging were followed up. The study endpoint was VTA, including sudden cardiac death and major ventricular arrhythmias. The CMR-derived LVRI was defined as the cubic root of the LV end-diastolic volume divided by the maximal LV wall thickness. Competing risk regression analysis and Kaplan-Meier analysis were used to evaluate the association of LVRI with VTA. RESULTS: Over 71-month median follow-up (interquartile range: 17-134 months), 35 (12.9%, mean age 46.7 years, 27 males) participants reached VTA events. The presence (62.9% vs. 60.2%, p = 0.761) and extent (6.9 ± 6.6 vs. 6.5 ± 8.3, p = 0.747) of late gadolinium enhancement (LGE) and LVEF (23.3 ± 6 vs. 21.9 ± 10.3, p = 0.197) were not significantly different between the patients with and without endpoint. Kaplan-Meier curve analysis showed that participants with LVRI ≥ 7.5 were more likely to experience VTA (p < 0.0001). In the multiple competing risk analysis, LVRI ≥ 7.5 (HR, 2.496; 95% CI: 1.213-5.138; p = 0.013) was observed as an independent predictor of VTA after adjusting for age, sex and left bundle branch block. CONCLUSIONS: For nonischemic DCM patients with LVEF < 35%, LVRI ≥ 7.5 was associated with lethal VTA events and provided incremental value over conventional CMR parameters. CRITICAL RELEVANCE STATEMENT: The left ventricular remodeling index (LVRI) was independently associated with ventricular tachyarrhythmias in dilated cardiomyopathy patients with LVEF < 35%, and warrants future multicenter validation to assess incremental value over established predictors for implantable cardioverter-defibrillator decision-making. KEY POINTS: Left ventricular ejection fraction did not exhibit significant prognostic value for end-stage dilated cardiomyopathy patients. Cardiac MRI (CMR)-assessed left ventricular remodeling index (LVRI) ≥ 7.5 was an independent predictor of ventricular tachyarrhythmia. LVRI provided incremental prognostic value over conventional CMR parameters.