Impaired Left Atrial Function in Fabry Disease: A Longitudinal Speckle-Tracking Echocardiography Study

Abstract

Fabry disease (FD) is characterized by the accumulation of sphingolipids in multiple organs, including the left atrium. It is uncertain if the left atrial (LA) reservoir, conduit, and contractile functions evaluated by speckle-tracking echocardiography are affected in Fabry cardiomyopathy and whether enzyme replacement therapy can improve LA function. In this retrospective cohort study, LA strain, strain rates, and phasic LA volumes were studied in 50 patients with FD and compared with values in 50 healthy control subjects. All three LA phasic functions were altered. Peak positive strain (reservoir function) was 38.9±14.9% versus 46.5±10.9% (P=.004), and late diastolic strain (contractile function) was 12.6±5.9% versus 15.6±5.3% (P=.010). In 15 patients who started enzyme replacement therapy during the study, most of the LA parameters improved at 1-year follow-up (peak positive strain from 32.0±13.5% to 38.0±13.5%, P=.006), whereas there was a trend toward deterioration in 15 patients who never received treatment (peak positive strain from 47.3±10.8% to 41.3±9.3%, P=.058). Nine patients with FD (21%) experienced new-onset atrial fibrillation or stroke during 4-year follow-up. By univariate analysis, peak positive strain and early diastolic strain demonstrated significant associations with clinical events, surpassing conventional echocardiographic parameters and clinical characteristics. LA reservoir, conduit, and contractile functions by speckle-tracking echocardiography were all affected in FD. Enzyme replacement therapy improved LA function. LA strain parameters were associated with atrial fibrillation and stroke.