CMR-derived left atrial strain predicts adverse events in dilated cardiomyopathy
Authors: Brusamolino M , Casas G , Miccoli D , Tomasino M , Rodenas-Alesina E , Faggiano A , Giustiniani A , Airale L , Badia-Molins C , Limeres J , Teixido-Tura G , Guala A , Ferreira-Gonzalez I , Pontone G , Rodriguez Palomares J F 
Published: January 2025

Abstract

Background
Dilated cardiomyopathy (DCM) is associated with an increased risk of major adverse cardiovascular events (MACE). However, current risk stratification methods are imperfect. Left atrial global longitudinal strain (LA GLS) is an increasingly acknowledged predictive parameter, yet its potential role in DCM is not well defined.

Purpose
This study aims to investigate the prognostic role of cardiac magnetic resonance (CMR)-derived LA GLS for the occurrence of MACE in patients with DCM.

Methods
A retrospective, longitudinal, single-centre CMR study of DCM patients was conducted. DCM was defined according to current guidelines. Clinical data was collected from electronic medical records and a blinded CMR analysis was performed. LA GLS was derived from CMR two-chamber cine images by a semiautomatic method and was categorized according to its median value. A composite MACE endpoint was defined as: heart failure (HF) (including unplanned HF visit or hospitalization, CRT implant, LVAD implant, heart transplantation), ventricular arrhythmias (including sudden cardiac death, ventricular fibrillation, sustained and non-sustained ventricular tachycardias, appropriate ICD shocks), systemic embolisms and/or all-cause death. The HF endpoint was also independently analysed due to its prevalence. Cox regression analysis was performed.

Results
A total of 181 DCM patients were included. The mean age was 55±15 years, and 34% were female. The indexed left ventricular end diastolic volume was 126±43 mL/m2, left ventricular ejection fraction was 35±13% and 67 patients (37%) had late gadolinium enhancement. Mean LA GLS was 22.2±16.3%. After a median follow-up of 3,6 (IQR 2,1- 5,6) years, 52 patients (29%) experienced at least one MACE: 32 (18%) HF events, 9 (5%) ventricular arrhythmias, 2 (1%) embolic strokes and 11 (6%) deaths. LA GLS was significantly lower in patients with MACE (17.7±12.7% vs 24.0±17.2%, p=0.019) and HF events (14.6±9.7% vs 23.9±16.9%, p=0.004) compared to those without.
Univariable and multivariable Cox regression analyses for MACE are shown in Table 1A. LA GLS was independently associated with MACE (HR 1.03; 95% CI: 1.01-1.05; p= 0.048; higher risk when lower LA GLS). Patients with a LA GLS below the median (18.7%) showed a 2-fold increased risk of MACE (Figure 1A).
Univariable and multivariable Cox regression analyses for HF events are shown in Table 1B. LA GLS (HR 1.04; 95% CI: 1.01-1.08; p= 0.036) and LVESVi (HR 1.01; 95% CI: 1.01-1.03; p= 0.025) were independently associated with HF events. Patients with a LA GLS &lt; 18.7% showed a 3-fold increased risk of HF (Figure 1B).

Conclusions
CMR-derived LA GLS is a predictor of outcomes in DCM beyond established prognostic variables. Patients with normal LA GLS show a better prognosis. If confirmed in larger studies, LA GLS could be used to enhance current risk stratification in DCM.
Table 1A-B
Figure 1A-B