Prognostic Utility of Left Atrial Strain From MRI Feature Tracking in Ischemic and Nonischemic Dilated Cardiomyopathy: A Multicenter Study

Abstract

<p>Background: MRI-based prognostic evaluation in patients with dilated cardiomyopathy (DCM) has historically used markers of late gadolinium enhancement (LGE) and feature-tracking (FT) derived left ventricular global longitudinal strain (LV-GLS). Early data indicate that FT-derived left atrial strain (LAS) parameters, including reservoir, conduit, and booster, may also have prognostic roles in such patients. Objective: To evaluate the prognostic utility of LAS parameters, derived from MRI FT, in patients with ischemic or nonischemic DCM, including in comparison with the traditional parameters of LGE and LV-GLS. Methods: This retrospective study included 811 patients with ischemic or nonischemic DCM [median age, 60 years; 640 men, 171 women] who underwent cardiac MRI at any of five centers. FT-derived LAS and LV-GLS were measured using two- and four-chamber cine images. LGE percentage was quantified. Patients were assessed for a composite outcome of all-cause mortality or heart-failure hospitalization. Multivariable Cox regression analyses were performed, including demographic characteristics, cardiovascular risk factors, medications used, and a wide range of cardiac MRI parameters. Kaplan-Meier analyses with log-rank tests were also performed. Results: A total of 419 patients experienced the composite outcome. Patients who did, versus did not, experience the composite outcome had larger LV-GLS (-6.7% vs -8.3%, p<.001), as well as smaller LAS reservoir (13.3% vs 19.3%, p<.001), LAS conduit (4.7% vs 8.0%, p<.001), and LAS booster (8.1% vs 10.3%, p<.001), but no significant difference in LGE (10.1% vs 11.3%, p=.51). In multivariable Cox regression analyses, significant independent predictors of the composite outcome included LAS reservoir (HR=0.96, p<.001) and LAS conduit (HR=0.91, p<.001). LAS booster and LGE were not significant independent predictors in the models. LV-GLS was a significant independent predictor only in a model that initially included LAS booster but not the other LAS parameters. In Kaplan-Meier analysis, all three LAS parameters were significantly associated with the composite outcome (p<.001). Conclusion: In this multicenter study, LAS reservoir and LAS conduit were significant independent prognostic markers in patients with ischemic or nonischemic DCM, showing greater prognostic utility than the currently applied markers of LV-GLS and LGE. Clinical Impact: FT-derived LAS analysis provides incremental prognostic information in patients with DCM.<br></p>