Long-Term Cardiovascular Mortality Linked to Post-Op AKI, CKD
Even surgery patients with stage 1 AKI without true organ damage had a 43% increase in cardiovascular mortality risk within 10 years compared with patients with no kidney disease.
Acute kidney injury (AKI) commonly occurs in patients undergoing vascular surgery and is associated with a high risk of cardiovascular-specific death similar to that observed with chronic kidney disease (CKD), researchers reported.
The relationship appears to strengthen with worsening kidney function and appears independent of other factors, such as the type of operation or co-existing conditions.
Azra Bihorac, MD, MS, of the University of Florida in Gainesville, and colleagues examined perioperative AKI, CKD occurrence, and cardiovascular mortality in 3,646 patients who underwent vascular surgery (open or endovascular) at a single teaching hospital from 2000 to 2010. The researchers defined AKI as a least a 50% and/or a 0.3-mg/dL increase in serum creatinine per Kidney Disease: Improving Global Outcomes (KDIGO) criteria,
Perioperative AKI developed in 49.4% of patients. according to results published online ahead of print in JAMA Surgery. The researchers calculated that CKD was present in 13.6% of patients.
Estimated cardiovascular mortality at 10 years was 31%, 30%, and 41%, respectively, for patients with AKI and no CKD, CKD without AKI, and AKI with CKD compared with just 17% for patients without any kidney disease. The odds of cardiovascular death were double for patients with AKI alone and with CKD alone; odds were triple for patients with both AKI and CKD. These chances were higher than for other risk factors, including aging, emergent surgery, and hemoglobin levels less than 10 g/dL.
According to the researchers, declining kidney function is not the only possible culprit; independent mechanisms may also be at work. In their analyses, they adjusted for competing causes of death, hemoglobin, and other factors.
“These findings reinforce the importance of preoperative CKD risk stratification through the application of consensus staging criteria for CKD using eGFR and albuminuria for all patients undergoing major vascular surgery, the authors wrote. “Preoperative and postoperative risk stratification for AKI 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.” They added that surgical follow-up care should include efforts to reduce renal and cardiovascular risks.
In an editorial accompanying the study, Christian de Virgilio, MD, and Dennis Yong Kim, MD, of Harbor-UCLA Medical Center in Torrance, Calif., commented: “Regardless of the strategies used, it is readily apparent that it is time to start paying closer attention to postoperative AKI.”
- Huber M Ozrazgat-Baslanti T, Thottakkara P, Scali S, Bihorac A, and Hobson C. Cardiovascular-Specific Mortality and Kidney Disease in Patients Undergoing Vascular Surgery. JAMA Surg. doi: 10.1001/jamasurg.2015.4526.