Assessing left atrial dysfunction in cardiac amyloidosis using LA-LV strain slope.

Area of Science:

• Cardiology
• Cardiovascular Imaging
• Cardiac Amyloidosis

Background:

• Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive myocardial infiltrative disease.
• Amyloid deposits in the myocardium lead to impaired cardiac function.
• Distinguishing ATTR-CM from other conditions like left ventricular hypertrophy (LVH) is crucial for timely treatment.

Purpose of the Study:

• To evaluate left atrial (LA) deformation and its relationship with left ventricular (LV) deformation in ATTR-CM patients.
• To compare LA-LV strain loops in ATTR-CM and LVH patients.
• To test the hypothesis that LA strain in ATTR-CM is abnormal and less dependent on LV strain compared to LVH.

Main Methods:

• Retrospective analysis of echocardiographic data from 30 ATTR-CM patients, 29 LVH patients, and 30 controls.
• Assessment of LV global longitudinal strain (LV-GLS) and peak atrial longitudinal strain (PALS).
• Construction of LA-LV strain loops and calculation of the LA-LV strain slope to analyze mechanical coupling.

Main Results:

• ATTR-CM patients showed significantly lower PALS and LA-LV strain slope values compared to LVH patients.
• Receiver operating characteristic (ROC) curve analysis indicated that PALS and LA-LV slope had higher areas under the curve (AUC) than LV-GLS for differentiating conditions.
• LA deformation analysis demonstrated an independent ability to distinguish ATTR-CM from LVH.

Conclusions:

• Left atrial deformation analysis, particularly PALS and the LA-LV strain slope, can effectively differentiate ATTR-CM from LVH.
• Analysis of LA-LV strain loops reveals mechanical dissociation in ATTR-CM, potentially indicating LA amyloid infiltration.
• These findings suggest that LA deformation assessment could facilitate earlier diagnosis and treatment initiation for ATTR-CM.