Baseline, Post-AKD Kidney Function Associated with Long-Term Prognosis After Dialysis for AKI

Heng-Chih Pan, MD

Credit: ResearchGate

Both baseline and post-acute kidney disease (AKD) kidney function may be important factors to consider for predicting long-term outcomes for patients with acute kidney injury (AKI) requiring dialysis, according to findings from a recent study.¹

Results published in JAMA Network Open highlight the association between baseline kidney function and major adverse cardiovascular events (MACEs) as well as end-stage kidney disease (ESKD), further identifying post-AKD kidney function as an independent factor linked to the long-term prognosis of patients receiving dialysis for AKI.¹

According to the US Centers for Disease Control and Prevention, kidney diseases are a leading cause of death in the United States, and an estimated 37 million US adults have CKD.2 If left untreated, CKD can progress to AKI – as the intermediate stage between AKI and CKD, less is known about AKD and its influence on patient outcomes.¹

“Considering the increasing number of hospitalized patients who develop AKI in a wide variety of clinical settings, there is a need to monitor patients with AKI to determine when kidney function status may play a role in the assessment of adverse outcomes,” wrote Heng-Chih Pan, MD, of Keelung Chang Gung Memorial Hospital in Taiwan, and colleagues.¹

To investigate the associations of baseline kidney function, AKD severity, and post-AKD kidney function with adverse outcomes in patients with AKI requiring dialysis, investigators examined patient data obtained from the National Health Insurance Research Database (NHIRD) in the Applied Health Research Data Integration Service from Taiwan’s National Health Insurance Administration. Patients with incident AKI requiring dialysis were identified between January 1, 2015, and December 31, 2018, according to ICD-9-CM and ICD-10-CM codes.¹

Investigators excluded patients < 18 years of age, patients who died or underwent additional dialysis within 90 days after discharge, and patients who did not have repeated serum creatinine (SCr) measurements during hospitalization, within 90 days after discharge, and at 90 to 180 days after discharge. In addition, patients with a history of kidney transplant were excluded.¹

The primary outcome of this study was a composite endpoint of all-cause mortality or incident MACEs including coronary artery disease, heart failure, and cerebrovascular accident. Secondary outcomes included the rates of permanent dialysis and readmission.¹

Of 22,232 patients with AKI requiring dialysis, 6703 with post-AKD kidney function follow-up and AKD stage information were enrolled. Among this cohort, the mean age was 68.0 (Standard deviation [SD], 14.7) years and the majority (57.4%) of patients were male.¹

During a mean follow-up period of 1.2 (SD, 0.9) years, the overall mortality rate was 28.3% (n = 1899), 11.1% of patients developed MACEs, and 16.7% developed ESKD. The mean time to all-cause mortality was 429.5 (SD, 321.6) days; MACE development was 393.6 (SD, 315.5) days; ESKD development was 367.7 (SD, 304.7) days; and readmission was 203.4 (SD, 243.8) days.¹

In multivariable analysis, baseline kidney function and post-AKD kidney function, but not AKD severity, were associated with all-cause mortality, MACEs, ESKD, and readmission. Additionally, investigators noted worse post-AKD kidney function was associated with a progressive and significant increase in the risk of adverse outcomes.¹

Investigators further noted a trend toward no kidney recovery in patients with advanced CKD at baseline. Accordingly, the prevalence of post-AKD CKD stage 5 increased with increasing baseline CKD stage.¹

In subgroup analyses, the association between poor post-AKD kidney function, defined as post-AKD CKD stages 3-5, and a greater risk of death remained consistent across age, sex, diabetes, hypertension, congestive heart failure, cerebrovascular disease, and use of renin-angiotensin-aldosterone system inhibitors.¹

“This study provides clinical evidence demonstrating that post-AKD kidney function could be considered an independent factor associated with the long-term prognosis of patients with AKI-D,” investigators concluded.¹ “On the basis of our results, we suggest that stratifying patients with AKI-D by post-AKD and baseline kidney function can improve the prognostic prediction along with objective information in clinical practice.”

References:

1. ^{Pan H, Chen H, Teng N, et al. Recovery Dynamics and Prognosis After Dialysis for Acute Kidney Injury. JAMA Netw Open. 2024;7(3):e240351. doi:10.1001/jamanetworkopen.2024.0351}
2. ^{US Centers for Disease Control and Prevention. Chronic Kidney Disease Basics. Chronic Kidney Disease Initiative. February 28, 2022. Accessed March 11, 2024. https://www.cdc.gov/kidneydisease/basics.html}