RAS Inhibitor Therapy May Prolong Survival After Acute Kidney Injury
In a Canadian study of patients who experienced AKI during hospitalization, treatment with an ACEI or ARB within 6 months of discharge was associated with a 15% lower risk for death after 2 years.
Renin angiotensin system (RAS) inhibitor therapy for patients who suffered from acute kidney injury (AKI) during a hospital stay may prolong survival, according to investigators.
In a study of 46,253 patients who experienced AKI while hospitalized in Alberta, Canada, those who received a prescription for an angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) within 6 months of discharge had a 15% lower risk for all-cause mortality after 2 years, Neesh Pannu, MD, of the University of Alberta in Canada, and colleagues reported in JAMA Internal Medicine. The investigators found an increased risk for death when ACEI or ARB therapy was started within 90 days of discharge, “suggesting that it may be better to start use of these medications after the first 90 days.” Patients without hypertension did not see a benefit.
Dr Pannu's team defined AKI as a 50% or 0.3 mg/dL increase between prehospital and peak in-hospital serum creatinine levels.
Despite the survival advantage, ACEI or ARB users also had a 28% higher risk for subsequent hospitalization for a renal cause—including AKI—congestive heart failure, hypervolemia, hyperkalemia, or malignant hypertension. They had no greater risks for progression to end-stage renal disease (ESRD) or a composite end point of ESRD and doubling of serum creatinine.
“These results suggest a potential benefit of ACEI or ARB use after AKI, but cautious monitoring for renal-specific complications may be warranted,” Dr Pannu and colleagues wrote.
The retrospective study was based on the Alberta Kidney Disease Network database 2008 to 2015. Roughly half (48%) of 46,253 adults (mean age 68.6; 52.8% male) who developed AKI during hospitalization were prescribed an ACEI or ARB after discharge. Another 38.6% never received an ACEI or ARB, and 13.4% did not continue taking an ACEI or ARB after discharge. Not continuing an ACEI or ARB was associated with 23% higher risk for early death.
The investigators propensity score matched 9456 ACE or ARB users to the same number of non-users. They adjusted models for comorbidities, ACEI or ARB use before admission, demographics, baseline kidney function, other factors related to index hospitalization (such as procedures and conditions), and use of prior health care services. They excluded patients who died, developed ESRD, required long-term dialysis, or received a kidney transplant before or during the hospitalization.
“In the search for improved long-term outcomes after AKI, prompt addition or resumption of RAS blockers seems to be judiciously indicated,” Robert J. Alpern, MD and Aldo J. Peixoto, MD, from the Yale University School of Medicine in New Haven, Connecticut, commented in an accompanying editorial. “In the meantime, we must monitor patients closely and wait for the science to address important pending questions.”
Brar S, Ye F, James MT, Hemmelgarn B, et al. Association of angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use with outcomes after acute kidney injury. JAMA Intern Med. DOI:10.1001/jamainternmed.2018.4749
Alpern RJ, Peixoto AJ. Use of renin angiotensin system blockers after acute kidney injury: Balancing tradeoffs. JAMA Intern Med.