How to distinguish between hypertrophic cardiomyopathy and left ventricular hypertrophy secondary to Fabry disease?

Abstract Introduction Fabry disease (FD) commonly leads to left ventricular hypertrophy (LVH) that could mimic sarcomeric hypertrophic cardiomyopathy (HCM). Purpose To determine the differences in echocardiographic parameters between FD patients with LVH and HCM patients. Methods We conducted a prospective study encompassing FD patients followed in a Reference Center of Lysosomal Storage Disorders. All patients performed a complete echocardiographic evaluation, including left ventricular strain analysis by two-dimensional speckle tracking imaging. Demographic, clinical characteristics and echocardiographic parameters were analysed. FD patients with LVH were compared with HCM patients, using Chi-square test for categorical variables and Student's T-test for continuous variables. The significance level was 0,05. Results A total of 91 FD patients were included, with a median age of 51 years-old and 62,6% of female predominance. 16,5% of patients were under enzymatic replacement therapy with agalsidase alpha and 7,7% were treated with chaperone therapy (migalastat). 33 FD patients (36%) had LVH and were older than HCM patients (63,6 vs 59,3 years-old; p=0,106). FD patients with LVH had lower interventricular septum (IVS) thickness (16,4 vs 19,6 mm, p<0,001), IVS/posterior wall ratio (1,3 vs 1,8, p<0,001), and left atrial volume index (34,45 vs 42,2 ml/m2; p=0,014). Left ventricle mass index was similar between the two groups (157,7 vs 155,5 g/m2; p=0,819), with lower left ventricular ejection fraction in FD patients (64,5% vs 70,5%; p<0,001). There were no significant differences in global longitudinal strain (−15,6% vs 15,9%; p=0,687), global circumferential strain (−19,9% vs −21,1%; p=0,218) and global radial strain (35,3% vs 33,7%; p=0,623). Interestingly, FD patients had lower base-to-apex circumferential strain gradient (5,7% vs 9,1%; p=0,002) and lower twist (17,5° vs 26,1°; p=0,001) than HCM patients. No significant differences were reported regarding mechanical dispersion (72,4 vs 71,2 ms; p=0,841). Conclusion The pattern of LVH is different between FD and HCM patients. In our study, we revealed that base-to-apex circumferential strain gradient and twist are echocardiographic parameters that could help distinguish both entities. Funding Acknowledgement Type of funding sources: None.