Acute Kidney Injury After Cardiac Transplantation: Foe or Common Innocent Bystander?

Abstract

Background: Heart transplantation (HT) is regarded as the treatment of choice for end-stage heart failure (ESHF) patients. Severe acute kidney injury (AKI) after HT is a frequent clinical problem with devastating consequences for HT recipients.

Methods: Data from 112 ESHF patients undergoing HT in 2010-2015 were retrospectively reviewed. The primary end point was the development of AKI stage III, and secondary outcomes were in-hospital and 1-year mortality according to Kidney Disease Improving Global Outcomes criteria.

Results: In total, 81 patients (72.3%) developed AKI, of which 33 (29.4%) developed AKI stage I, 18 (16%) stage II, and 30 (26.7%) stage III; within this group, 27 recipients (24%) required renal replacement therapy (RRT). Overall hospital mortality was 14%. However, when stratifying by AKI stage, hospital mortality increased from 0% to 46% comparing recipients without AKI and those with AKI stage III, respectively (P = .001). In the same way, 1-year mortality increased from 6% to 53% for recipients without AKI compared with those who developed AKI stage III (log-rank test for trend: P = .001). Recipients that required RRT had a 1-year mortality of 59.2% compared with 5.8% in those without RRT requirement.

Conclusions: The findings indicate that AKI stage III is common after HT and adversely affects early and late mortality. Clinical variables together with perioperative hemodynamic assessment could add more powerful prognostic information to predict severe AKI before HT and therefore evaluate potential heart-kidney recipients.