Higher MAP linked with AKI reversal among hospitalized patients

A 5 mm Hg increase in mean arterial pressure (MAP) was linked with a small but significant increase in the likelihood of reversal of acute kidney injury (AKI), according to a retrospective study of patients hospitalized with decompensated cirrhosis.

Higher mean arterial pressure (MAP) significantly increases the likelihood of recovery from acute kidney injury (AKI) in patients with cirrhosis, regardless of severity of AKI or AKI phenotype, new research showed.

Investigators collected data on incident AKI episodes in 702 patients hospitalized with decompensated cirrhosis. They defined AKI as a 50% or more increase in creatinine from an outpatient baseline (the most recent value seven to 365 days before admission) that required hospitalization. To measure MAP's impact on AKI reversal, researchers used Cox regression models with time beginning at the time of peak creatinine and ending at death, discharge, or AKI reversal. Persistent AKI was defined as taking at least 48 hours to reverse. All patients were hospitalized at the University of California, San Francisco, between 2011 and 2022. Findings were published by Hepatology on March 27.

Of the patients hospitalized with AKI, those whose AKI reversed had a higher MAP on average (difference, 2.1 mm Hg; P<0.05) and a greater increase in MAP over time (0.1 mm Hg per hour; P<0.001). Overall, each 5 mm Hg increase in MAP was associated with 1.07 times the hazard of AKI reversal (P<0.01) after adjustment for confounders. Half of the patients (n=350) had full AKI recovery at a median of three days. Among the 279 patients with persistent AKI, each 5 mm Hg increase in MAP was associated with 1.19 times greater likelihood of AKI reversal (P<0.001) after adjustment. Data showed that among all hospitalized patients, those with lower MAP were sicker and had a greater burden of ascites and a higher stage of AKI.

The results show the importance of MAP as a clinical tool to promote recovery of kidney function in patients with cirrhosis hospitalized for AKI, according to the study authors. "Regardless of whether a patient had an HRS [hepatorenal syndrome]-AKI phenotype or a non-HRS-AKI phenotype, MAP was equally associated with AKI recovery," they noted.

Limitations include that the study did not examine other potential endpoints like partial AKI recovery and death. The results also may not be generalizable to wider populations, but overall, the authors "believe these data highlight the importance of MAP as a pharmacodynamic measure to be followed among cirrhosis patients hospitalized with AKI," they concluded.