Echocardiographic predictors of ventricular arrhythmias in patients with non-ischemic cardiomyopathy

Objective: Ventricular arrhythmias (VA) portend a poor prognosis in non-ischemic cardiomyopathy (NICM). In this meta-analysis we evaluated if left ventricular (LV) global longitudinal strain (GLS) and LV mechanical dispersion (LVMD) are associated with VA, specifically in NICM patients.Methods: A systematic review and meta-analysis was performed to determine the predictive value of LV GLS and LVMD for VA in NICM patients. VA endpoints were a composite of sudden cardiac death, VA events (including ventricular tachycardia or ventricular fibrillation), cardiac arrest and appropriate implantable cardioverterdefibrillator (ICD) therapy. Hazard or odds ratios for univariate models were extracted for the relationship between LV GLS and LVMD with VA endpoints. Results: A total of 984 patients from 6 published studies were included; 231 patients (23.5%) experienced the composite endpoint. NICM patients who experienced VA endpoints had LV GLS impairment compared to those without (weighted mean difference -1.93%; 95% confidence interval (CI) -2.77 to -1.10; p < 0.001) and LV GLS was related to VA endpoints (hazard ratio: 1.12, 95% CI 1.07-1.17, p < 0.001; odds ratio: 1.22, 95% CI 1.08-1.38, p = 0.002). Four studies reported mean LVMD (weighted mean -10.05 ms; 95% CI -28.25 to 8.14; p = 0.28), with 3 reporting risk ratios (1 reported odds ratio and 2 hazard ratios). Only odds ratio demonstrated statistical significance (hazard ratio: 0.47, 95% CI 0.01-22.25, p = 0.70; odds ratio: 1.59, 95% CI 1.14-2.22, p = 0.007).Conclusion: LV GLS impairment demonstrates value for predicting VA endpoints in NICM patients. Inclusion of LV GLS may be appropriate in the surveillance, screening, and clinical management of NICM patients.