Severe Acute Kidney Injury after Cardiac Transplantation is a Marker of Poor Early Outcome and Impacts on Late Renal Function - A UK Cohort Study

Abstract

Purpose Severe acute kidney injury (AKI) requiring haemofiltration is associated with worse mortality post-cardiac transplantation, but its long-term renal consequences are not known. This study analysed its impact on the mortality and long-term renal function in adult cardiac recipients in the UK. Methods Characteristics including age, gender, pre-op cardiac pathology, and diabetes mellitus (DM), survival status, peri-op renal function, and post-op haemofiltration of all adult recipients, who underwent cardiac transplantation between 1995 and 2017 in the UK, were retrieved from the UK Transplant Registry. Serum creatinine was collected immediately pre-op, 3-month post-op, and annually afterwards, and eGFR was calculated using the abbreviated MDRD equation. Binary logistic regression was used to identify risk factors for post-op haemofiltration requirement. Multivariable Cox regression was performed to identify risk factors associated with mortality and development of stage 4 or 5 chronic kidney disease (eGRF Results From 1995 to 2017, 3365 adult patients received cardiac transplantation across 6 centres in the UK. Among them, 876 (26.0%) patients developed post-op severe AKI requiring haemofiltration. The risk factors of post-op haemofiltration include congenital cardiac disease (p = 0.002, OR 1.90) and age (p = 0.003, OR 1.01). Both 1-year survival, 59.8% (95% CI: 56.6-63.2%), and 5-year survival, 50.7% (95% CI: 47.2-54.4%) of this group were strikingly lower than that of the non-haemofiltration group, 89.2% (95% CI: 88.0-90.5%), and 78.4% (95% CI: 76.7-80.1%). Age (p = 0.002, HR 1.01), insulin dependent DM (p =0.002, HR 1.45), and haemofiltration (p Conclusion This study confirmed that severe AKI requiring haemofiltration is associated with worse mortality, especially within the first year post-op. Moreover, as predicted in the studies in non-transplant patients, it has an adverse impact on the long-term deterioration of recipients’ renal function.