Speckle tracking echocardiography (STE) in patients with primary hyperoxularia type 1 (PH1)

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Primary Hyperoxaluria type 1 (PH1) is a rare, inherited metabolic disorder of glyoxylate metabolism characterized by oxalate overproduction, leading to end-stage kidney disease (ESKD) in more than half of all patients. As renal function deteriorates the ability of the kidneys to excrete the excess of oxalate is increasingly compromised resulting in elevated concentrations of oxalate in the blood and progressive systemic deposition of calcium-oxalate crystals in virtually all tissues, a situation referred to as systemic oxalosis. A wide spectrum of cardiac abnormalities are reported in PH1 patients, including presymptomatic myocardial disease early in the disease course. We aimed to further determine cardiac manifestations in a heterogenous cohort of PH1 patients by conventional and speckle tracking echocardiography (STE). Methods Data from 38 genetically confirmed PH1 patients were included in this two-centre study and compared to age- and sex-matched controls. Comprehensive echocardiographic analysis (including STE) was performed. PH1 patients were subdivided in three groups based on stage of chronic kidney disease (CKD) and transplantation status (CKD1-4 (n = 24), CKD5 (n = 7) and post-liver transplantation (n = 7)). Results Left-ventricle ejection fraction (LV EF) was preserved in all subjects. PH1 patients had a decreased global longitudinal strain compared to healthy controls, with a mean difference of -2.28 (p < 0.001). In patients with CKD1-4 decreased LS values were solely found in all apical segments, with a mean difference of -5.3 (p < 0.001) as compared to healthy controls. In patients whom already progressed to end-stage kidney disease (ESKD, defined as CKD5) diastolic dysfunction is noted, with preserved systolic function. Conclusion Pre-symptomatic myocardial dysfunction is present in PH1 patients with mild renal impairment and relatively normal plasma oxalate values. This indicates that cardiac screening is warranted in all PH1 patients, irrespective of renal function.