Risk of chronic kidney disease in patients with acute kidney injury following a major surgery: a US claims database analysis

Lay Summary Acute kidney injury (AKI) is a disease that is common in patients who have had a serious surgery. We studied whether having AKI after a serious surgery affects the risk of developing chronic kidney disease (CKD) stage & GE;3 (which is known as 'moderate-severe CKD') or the risk that pre-existing CKD progresses to moderate-severe CKD. The study also looked into how AKI affects the risks of other events, such as having a heart attack, having a stroke, experiencing heart failure, being hospitalized and experiencing other side effects. We used information from real patients to study these health outcomes using insurance claims. Our research showed that patients who experienced AKI after a serious surgery are at high risk of getting moderate-severe CKD or worsening of their pre-existing CKD. Furthermore, the risk of other side effects, such as having a heart attack or stroke, was also high in these patients. Background Acute kidney injury (AKI) is a common complication after major surgery. This study assessed the risk of developing or worsening of chronic kidney disease (CKD) and other clinical outcomes in patients experiencing AKI after major surgery. Methods This retrospective observational study used Optum's de-identified Clinformatics Data Mart Database to investigate cardiorenal outcomes in adult patients at the first AKI event following major surgery. The primary outcome was CKD stage & GE;3; secondary outcomes included myocardial infarction (MI), stroke, heart failure, all-cause hospitalization, end-stage kidney disease, need for dialysis or kidney transplant and composite measures. Follow-up was up to 3 years. Additionally, the effect of intercurrent events on the risk of clinical outcomes was assessed. Results Of the included patients (N = 31 252), most were male (61.9%) and White (68.9%), with a median age of 72 years (interquartile range 64-79). The event rates were 25.5 events/100 patient-years (PY) for CKD stage & GE;3, 3.1 events/100 PY for end-stage kidney disease, 3.0 events/100 PY for dialysis and 0.1 events/100 PY for kidney transplants. Additionally, there were 6.9 events/100 PY for MI, 8.7 events/100 PY for stroke and 49.8 events/100 PY for all-cause hospitalization during follow-up. Patients with AKI relapses as intercurrent events were more likely to develop CKD stage & GE;3 than those with just one AKI event after major surgery. Conclusion This analysis demonstrated that patients experiencing AKI following major surgery are at high risk of developing severe CKD or worsening of pre-existing CKD and other cardiorenal clinical outcomes such as MI and stroke.