Acute kidney injury (AKI) outcome, a predictor of long-term major adverse cardiovascular events (MACE)

Background and objectives: The incidence of acute kidney injury (AKI) in hospitalized patients is increasing. Many of these patients survive the immediate post-AKI period and may be prone to developing long-term complications of AKI. This study aimed to determine whether complete recovery following an episode of AKI is associated with a lower risk of long-term major adverse cardiovascular events (MACE). Design: Retrospective cohort study. Setting and participants: Adults admitted to the University of Virginia Medical Center between January 1, 2002 and December 31, 2012 who developed hospital-acquired AKI. Predictor: AKI was defined as an increase in serum creatinine (SCr) by >= 0.3 mg/dL from the baseline and or requirement for acute dialysis during index hospitalization. Complete recovery was defined as a return of SCr to less than 1.25 times the baseline value and not dialysis dependent. Outcome and measurement: MACE was defined as subsequent admission for myocardial infarction, stroke or transient ischemic attach and heart failure using ICD-9-CM codes. Results: Overall, 11,538 patients survived beyond 90 days of AKI and had data available for analysis. Of the 9,673 survivors of AKI in whom recovery could be assessed, 7170 (74.12%) had complete renal recovery. MACE occurred in 27.28% of our study population over a median follow-up period of 399 days. 28.19% of patients who completely recovered renal function developed MACE, while only 32.48% did in those who did not recover completely. Patients who had complete recovery had a lower risk of long-term MACE when compared with those without complete recovery (adjusted hazard ratio 95% confidence interval (CI): 0.774 (0.713, 0.842)). Limitation: Measurement of albuminuria was not available. Conclusion: Complete renal recovery after an episode of AKI in patients with normal baseline kidney function is associated with a lower risk of long-term MACE when compared with those who did not fully recover.