Global Incidence and Outcomes of Adult Patients With Acute Kidney Injury After Cardiac Surgery: A Systematic Review and Meta-Analysis

ObjectivesTo estimate the global incidence and outcomes of acute kidney injury (AKI) after cardiac surgery in adult patients.DesignA systematic review and meta-analysis.SettingCardiac surgery wards.ParticipantsAdult patients after cardiac surgeryInterventionsNone.Measurements and Main ResultsThe authors searched PubMed, Web of Science, Cochrane Library, OVID, and EMBASE databases for all articles on cardiac surgery patients published during 2004 to 2014. Meta-analyses were conducted to generate pooled incidence, mortality, ICU length of stay, and length of hospital stay. The authors also described the variations according to study design, criteria of AKI, surgical methods, countries, continents, and their economies. After a primary and secondary screen, 91 observational studies with 320,086 patients were identified. The pooled incidence rates of AKI were 22.3% (95% confidence interval [CI], 19.8 to 25.1) in total and 13.6%, 3.8%, and 2.7% at stages 1, 2, and 3, respectively, whereas 2.3% of patients received renal replacement therapy. The pooled short-term and long-term mortality were 10.7% and 30%, respectively, and increased along with the severity of stages. The pooled unadjusted odds ratio for short-term and long-term mortality in patients with AKI relative to patients without AKI was 0.144 (95% CI, 0.108 to 0.192, p<0.001) and 0.342 (95% CI 0.287-0.407, p<0.001), respectively. The pooled average ICU length of stay and length of hospital stay in the AKI group were 5.4 and 15 days, respectively, while they were 2.2 and 10.5 days in the no-AKI group.ConclusionsAKI is a great burden for patients undergoing cardiac surgery and can affect short-term and long-term prognoses of these patients.