Acute Kidney Injury after Heart Transplantation: Risk Stratification is Good; Risk Modification is Better-But can we do it?

Zhu MZL, Marasco SF, Evans RG, Kaye DM, McGiffin DC Transplant Direct DOI 10.1097/TXD.0000000000001635

Background: Acute kidney injury (AKI) is a frequent and consequential complication after heart transplantation (HTx). When evaluated using current Kidney Disease Improving Global Outcomes (KDIGO) consensus criteria, the incidence of AKI after HTx is 40% to 80%, whereas the need for perioperative renal replacement therapy (RRT) ranges from 5% to 35%. Even mild AKI appears to adversely impact both early and long-term outcomes after HTx, while severe AKI or need for RRT is associated with markedly higher mortality and permanent renal impairment. The aetiology of AKI in the HTx setting is clearly complex and multifactorial. Preexisting kidney dysfunction is both driven and exacerbated by end-stage heart failure, cardiorenal interactions, and comorbidities. The kidneys are also particularly sensitive to a range of factors that occur commonly during HTx, including renal hypoperfusion, impaired renal oxygenation, prolonged cardiopulmonary bypass, vasoplegia, and the use of vasopressors, primary graft dysfunction (PGD) and nephrotoxic drugs such as calcineurin inhibitors.