Left atrial strain on CMR, a useful prognostic marker in dilated cardiomyopathy: JACC

Netherlands: Left atrial conduit strain is a promising independent prognostic predictor in patients with dilated cardiomyopathy, incremental to LGE and superior to LVEF, LAVI, and LV-GLS, states an article published in the JACC: Cardiovascular Imaging.

Dilated Cardiomyopathy (DCM) is a disease of the heart muscle characterized by enlargement and dilation of one or both of the ventricles along with impaired contractility. It has an estimated prevalence of approximately 1: 250–400 in the general population. Dilated cardiomyopathy is a progressive, usually irreversible, disease that if untreated, can lead to heart failure.

Cardiac magnetic resonance (CMR) has emerged as an indispensable diagnostic tool in the workup of DCM patients, as it can provide accurate and reproducible measurements of biventricular volumes, mass, and function, as well as detailed morphology information, overcoming most of the limitations inherent to other imaging modalities. The left atrium is an early sensor of left ventricular (LV) dysfunction, but the prognostic value of left atrial (LA) function (strain) on CMR in dilated cardiomyopathy (DCM) remains unknown.

Anne G., Maastricht University Medical Center, the Netherlands, and colleagues conducted a study to evaluate the prognostic value of CMR-derived LA strain in DCM.

The authors conducted a retrospective study involving 488 patients(median age: 54years) with dilated cardiomyopathy (DCM). The primary endpoint was the combination of sudden or cardiac death, hospitalization owing to heart failure, or life-threatening arrhythmias. Given the nonlinearity of continuous variables, cubic spline analysis was performed to dichotomize.

Key findings of the study:

• Age, New York Heart Association (NYHA) functional class >II, presence of late gadolinium enhancement (LGE), LV ejection fraction (LVEF), LA volume index (LAVI), LV global longitudinal strain (GLS), and LA reservoir and conduit strain were univariably associated with the outcome (all P < 0.02)

• LA conduit strain was a stronger predictor of outcome compared with reservoir strain.

• An NYHA functional class >II (HR, 1.81), LA conduit strain (HR, 3.65), and the presence of late gadolinium enhancement (HR, 2.33) were consistent predictors of the primary composite endpoint whereas age, N-terminal pro–B-type natriuretic peptide, LVEF, left atrial ejection fraction, LAVI, and LV GLS was not.

• Adding LA conduit strain to other independent predictors (NYHA functional class and LGE) significantly improved the calibration, accuracy, and reclassification of the prediction model.

The authors conclude that LA conduit strain on CMR is a strong independent prognostic predictor in DCM, superior to LV GLS, LVEF, and LAVI, and incremental to LGE. DCM patient management should include LA conduit strain to improve risk stratification.

Reference:

Anne G. Raafs, Jacqueline L. Vos, Michiel T.H.M. Henkens, Bram O. Slurink, Job A.J. Verdonschot, Daan Bossers, Kit Roes, Suzanne Gerretsen, Christian Knackstedt, Mark R. Hazebroek, Robin Nijveldt, Stephane R.B. Heymans, Left Atrial Strain Has Superior Prognostic Value to Ventricular Function and Delayed-Enhancement in Dilated Cardiomyopathy, JACC: Cardiovascular Imaging,Volume 15, Issue 6,2022,https://doi.org/10.1016/j.jcmg.2022.01.016.