Dialysis Requirement and Long-Term Major Adverse Cardiovascular Events in Patients with Chronic Kidney Disease and Superimposed Acute Kidney Injury

Abstract

Background: Chronic kidney disease (CKD) patients who experience superimposed acute kidney injury (AKI) have been shown to be at higher risk of long-term sequelae of AKI when compared to those who do not experience AKI. It remains unclear whether the need for temporary dialysis intervention following superimposed AKI in patients with CKD has any effect on the long-term major adverse cardiovascular events (MACE). This study examines the relationship between temporary dialysis therapy following AKI and long-term major cardiovascular events in patients with background CKD. Methods: The study population consists of adults who developed AKI while on admission at the University of Virginia Medical Center between January 1, 2002 and December 31, 2012, and who had preadmission estimated glomerular filtration rate (eGFR) between 20 and 60 mL/min/1.73 m² and survived beyond 30 days of AKI. Demographic and baseline clinical variables were used to generate propensity score. Survivors who had temporary dialysis were matched to those managed conservatively according to the propensity score in a ratio of 1:3. Results: Overall, 6,634 (n = 381 and 6,253 in the temporary dialysis-requiring AKI and non-dialysis AKI groups respectively) met entry criteria for the full cohort. Of these, 381 (5.7%) received temporary dialysis. There were 3,147 (47.4% of all patients) MACE events during the study period. The crude incidence for MACE after 30 days of AKI was similar in both dialyzed and non-dialyzed patients. After the propensity score matching, the adjusted hazard ratio for MACE in dialyzed versus non dialyzed patients was 1.162 (95% CI 0.978-1.381). Conclusions: Treatment of AKI with temporary dialysis in hospitalized patients with baseline eGFR between 20 and 60 mL/min/1.73 m² was not associated with an increased risk for subsequent admission for MACE. If confirmed by prospective studies, clinicians may not need to worry that the dialysis procedure may contribute to additional risk for long-term MACE in CKD patients with superimposed AKI.