Left atrial structural and functional remodelling in Fabry disease and cardiac amyloidosis: A comparative analysis

Area of Science:

• Cardiology
• Cardiomyopathy Research
• Cardiac Imaging

Background:

• Fabry disease (FD) and transthyretin cardiac amyloidosis (TTR CA) are hypertrophic cardiomyopathies with overlapping features like left atrial (LA) enlargement.
• Direct comparative data on LA remodeling between FD and TTR CA are limited.

Purpose of the Study:

• To conduct a comparative analysis of left atrial (LA) remodeling in patients with Fabry disease (FD) and transthyretin cardiac amyloidosis (TTR CA).

Main Methods:

• Prospective study including 114 patients (31 FD, 83 TTR CA) with left ventricular hypertrophy (LVH).
• Comparative analysis of left ventricular (LV) function, LA volumes, and LA mechanics (reservoir, conduit, and active emptying function).
• Multivariable regression analyses and assessment of echocardiographic parameter accuracy for disease discrimination.

Main Results:

• Patients with TTR CA exhibited worse LV systolic and diastolic function despite similar LVH compared to FD patients.
• LA maximal volume index was not significantly different, but LA minimal volume index was larger in TTR CA (p=0.001).
• All phases of LA mechanics were significantly more impaired in TTR CA (p<0.001), and LA reservoir strain independently correlated with TTR CA (p≤0.001).

Conclusions:

• Transthyretin cardiac amyloidosis (TTR CA) presents with more advanced structural and functional left atrial (LA) remodeling than Fabry disease (FD) in the context of similar left ventricular hypertrophy (LVH).
• The association between TTR CA and LA dysfunction is robust, even after adjusting for confounders.
• Left atrial (LA) function demonstrated the highest accuracy in differentiating between TTR CA and FD.