Acute kidney injury is common in patients undergoing vascular surgery

Nearly half of patients undergoing vascular surgery had perioperative acute kidney injury, which was associated with an increased risk for cardiovascular mortality, according to a 10-year analysis of procedures at a tertiary care teaching hospital.

Lead researcher Matthew Huber, of the University of Florida, and colleagues published their results online in JAMA Surgery on Dec. 23.

They cited previous research that found chronic kidney disease was associated with excess 30-day mortality and was a risk factor for 1-year mortality after peripheral vascular interventions and abdominal aortic aneurysm repair. Other studies have shown acute kidney injury is a common complication after surgeries.

In this study, the researchers analyzed 3,646 patients who were at least 18 years old and were admitted to the hospital for longer than 24 hours after major vascular surgery from Jan. 1, 2000 to Nov. 30, 2010. They assessed survival through Jan. 31, 2014.

The researchers defined acute kidney injury as at least a 50 percent and/or a 0.3 mg/dL increase in serum creatinine level from the preoperative reference value.

Of the patients, 57.3 percent had evidence of kidney disease during hospitalization, while 13.6 percent had chronic kidney disease that did not require renal replacement therapy.

During hospitalization, 49.4 percent of patients developed acute kidney injury, and 81.3 percent of those patients did not have underlying chronic kidney disease. Patients with kidney disease were more likely to be older, African American, have comorbid congestive heart failure and have an admission hemoglobin level lower than 10 g/dL, according to the researchers.

The adjusted cardiovascular mortality estimates at 10 years were 17 percent for patients with no kidney disease, 31 percent for patients with acute kidney injury but no chronic kidney disease, 30 percent for patients with chronic kidney disease but no acute kidney injury and 41 percent for patients with acute kidney injury and chronic kidney disease.

The leading causes of mortality among those who died during the study were cardiovascular disease (53.6 percent) and cancer (11.0 percent).

“These findings reinforce the importance of preoperative [chronic kidney disease] risk stratification through the application of consensus staging criteria for [chronic kidney disease] using eGFR and albuminuria for all patients undergoing major vascular surgery,” the researchers wrote. “Preoperative and postoperative risk stratification for [acute kidney injury] using clinical scores and urinary biomarkers similarly can help to direct the implementation of simple and inexpensive preventive strategies in the perioperative period that could prevent or mitigate further decline in kidney function.”

The study had a few limitations, according to the researchers, including its retrospective design and use of a single center. However, they said they implemented multivariable adjustments and that the center has a heterogeneous patient population from throughout Florida who undergo a variety of procedures, which could help make the results more generalizable.

“The appropriate transition of patients undergoing surgery to follow-up in the outpatient setting with an emphasis on the prevention of kidney disease progression and mitigation of cardiovascular risk can be an important factor in improving the care of the patient undergoing vascular surgery who has [acute kidney injury] and/or [chronic kidney disease],” they wrote. “Our findings present compelling evidence that such efforts are warranted and justifiable.”