Natural History of Cardiac and Peripheral Vascular Death In ESKD: An Australian And New Zealand Data Linkage Study

Abstract

Introduction
Cardiovascular disease is a leading cause of death in patients with end-stage kidney disease (ESKD). However, ascertaining the impact of cardiovascular deaths has not been well characterised over long periods of follow-up and across different treatment states. Further insights into the lifetime risk of cardiovascular death are required to better inform clinical practice and economic planning.

Objectives and Approach
We performed a population-based cohort study on incident patients receiving ESKD treatment from the Australian and New Zealand Dialysis and Transplant registry (ANZDATA). Cardiac/vascular deaths were determined from ICD-10-AM codes listed in the underlying cause of death obtained via data linkage with the Australian National Death Index and New Zealand Mortality Collection database. We estimated mortality rates from cardiac/vascular death across time from ESKD treatment, and calculated probability of death and transplant status over time using multistate models.

Results
Across 60,823 incident ESKD patients and 381,874 person-years of follow-up, 22% (7,551) of deaths were from cardiac/vascular disease. At 15 years from treatment, 15.6% of patients had died from cardiac/vascular causes, most of whom never received a transplant (13.6% vs 2.0% of cohort). Within the first year of dialysis, cardiac/vascular mortality was highest in the second month, at 3,632/100,000pys. Improvements in cardiac/vascular mortality with calendar year were only seen after 9 months of dialysis. Transplant recipients had consistently lower cardiac/vascular mortality rates (598/100,000 pys) compared to dialysis patients. However, comorbid cardiovascular disease was a risk factor for graft failure and death in transplant recipients (HR:1.52, 95% CI:1.42-1.62).

Conclusion / Implications
Despite improvements in cardiac/vascular outcomes over time, cardiovascular death remains common in ESKD, particularly in the first few months of treatment. A greater focus on secondary prevention in earlier stages of chronic kidney disease may improve outcomes in new ESKD patients.