Background:

Chronic kidney disease (CKD) is a frequently seen complication after cardiac transplantation and is partly explained by the prolonged use of calcineurin inhibitors. However, few data are present on the consequences of acute kidney injury (AKI) in the post-operative period. In the present study, incidence and impact of AKI on mortality and renal function was studied.

Methods:

We conducted a retrospective cohort study evaluating all cardiac transplant recipients ≥18 years, between 1984-2012. Outcome was the incidence of AKI in the post-operative period and renal function and overall survival after 1 year. AKI was defined by de Kidney Disease Improving Global Outcome criteria.

Results:

The study population included 531 patients; median age was 51 years and 78% of male gender. Median estimated glomerular filtration rate (GFR) at baseline was 60 ml/min/1.73m2. 405(76%) met the AKI criteria. 211(40%) had AKI stage 1, 119(22%) stage 2 and 75(14%) stage 3. 25 patients (5%) required renal replacement therapy (RRT). Independent risk factors for AKI and increase in AKI stage: body-mass index (BMI), postoperative right ventricle (RV) failure and renal function at baseline. A higher age and the postoperative use of induction therapy were associated with better outcome. One-year overall survival was 88% and 1-year renal survival censored for death was 99%. Survival rates in patients without AKI, stage 1, 2 and 3 were 95%, 92%, 88% and 85%, respectively (log-rank test p=0.065). In patients that required RRT 1-year survival was 72% (log-rank test p=0.001). Independent risk factors for mortality: age, postoperative overall graft failure and time on mechanical ventilation. A trend was observed for the association between AKI requiring RRT and 1-year mortality. After 1 year, 8 (2%) patients had CKD0-1 (eGFR>90), 94(20%) CKD-2 (eGFR:61-90), 323(69%) CKD-3 (eGFR:31-60), 42(9%) CKD-4 (eGFR:16-30) and 4(1%) CKD-5 (eGFR≤15). Median eGFR at 1 year in patients without AKI, stage 1, 2 and 3 were 50, 45, 46 and 44, respectively. Independent risk factors for a lower eGFR 1 year after transplantation: age, BMI, AKI stage, preoperative use of ECMO and renal function at baseline. Male gender and longer time on mechanical ventilation were associated with better outcome.

Conclusions:

AKI is highly frequent after cardiac transplantation and a significant determinant of higher mortality and lower renal function 1 year after transplantation.

« Back to 2015 American Transplant Congress