Patients in the highest oxalate quartile (>59.7 M) had a 40% increased risk for cardiovascular events and a 62% increased risk of sudden cardiac death.
Germany: The increased concentration of serum oxalate in dialysis patients raises the risk for cardiovascular events and sudden cardiac death, show results from a post-hoc analysis of the German Diabetes Dialysis Study. The study is published in the Journal of the American Society of Nephrology.
The clinical significance of accumulating toxic terminal metabolites such as oxalate in kidney failure patients is poorly understood. Anja Pfau, Department of Nephrology and Medical Intensive Care, Charité Universitätsmedizin Berlin, Berlin, Germany, and colleagues aimed to evaluate serum oxalate concentrations and risk of all-cause mortality and cardiovascular events in a cohort of kidney failure patients requiring chronic dialysis.
For this purpose, they performed a post-hoc analysis of the randomized German Diabetes Dialysis Study (4D Study); this study included 1255 European hemodialysis patients with diabetes followed up for a median of 4 years.
The analysis included 1,108 European patients (with a median oxalate concentration of 42.4 µM)with diabetes who were on maintenance hemodialysis, with researchers validating the findings in a separate cohort of 104 patients receiving dialysis in the United States.
The research yielded the following findings:
During follow-up, 548 died, including 139 (25.4%) from sudden cardiac death.
A total of 413 patients reached the primary composite cardiovascular endpoint (cardiac death, nonfatal myocardial infarction, and fatal or nonfatal stroke).
Patients in the highest oxalate quartile (≥59.7 µM) had a 40% increased risk for cardiovascular events (adjusted hazard ratio [aHR], 1.40) and a 62% increased risk of sudden cardiac death (aHR, 1.62), compared with those in the lowest quartile (≤29.6 µM).
The associations remained when accounting for competing risks and with oxalate as a continuous variable.
"Our findings showed that elevated serum oxalate is a novel risk factor for cardiovascular events and sudden cardiac death in dialysis patients," wrote the authors. "However, there is a need for further studies to test whether oxalate-lowering strategies improve cardiovascular mortality in dialysis patients."
Reference:
The study titled, "High Oxalate Concentrations Correlate with Increased Risk for Sudden Cardiac Death in Dialysis Patients," is published in the Journal of the American Society of Nephrology.
DOI: https://jasn.asnjournals.org/content/early/2021/07/19/ASN.2020121793