Impact of Acute Kidney Injury and Baseline Renal Impairment on Prognosis Among Patients Undergoing Percutaneous Coronary Intervention

Background: Both chronic kidney disease (CKD) and acute kidney injury (AKI) are associated with adverse consequences among patients undergoing percutaneous coronary intervention (PCI). However, it remains undetermined whether the impact of CKD and post-PCI AKI are similar. We aimed to discriminate between the impact of CKD and post-PCI AKI on short- and long-term outcomes. Methods: This retrospective cohort study included 1,100 patients undergoing PCI at a tertiary hospital. Based on baseline kidney function, patients were categorized as having preserved or impaired renal function, defining as an estimated glomerular filtration rate (eGFR) of >= and < 45 ml/min/1.73 m(2), respectively. Post-PCI AKI was defined as >= 100% relative increase between baseline and post-procedural serum creatinine. Results: Post-PCI AKI was associated with an increased risk of 90-day mortality [odds ratio (OR): 22.03, 95% confidence interval (CI): 10.36-46.88], long-term mortality [hazard ratio (HR): 6.63, 95% CI: 4.31-10.20], and composite endpoint of future end-stage renal disease (ESRD) and death (HR: 6.19, 95% CI: 4.06-9.42). Impaired kidney function at baseline was associated with an increased risk of future ESRD and composite endpoint of ESRD and death (for every 10 unit increase in eGFR, HR: 0.25, 95% CI: 0.14-0.43, and HR: 0.89, 95% CI: 0.82-0.97, respectively). The impact of post-PCI AKI outweighed that of impaired baseline renal function on short- and long-term prognosis. Patients with impaired baseline renal function who developed AKI following PCI had the worst prognosis. Conclusions: Both post-PCI AKI and CKD were associated with a poor prognosis. Post-PCI AKI was more important than baseline renal function to predict long-term mortality and composite outcomes. The systemic pathophysiologic change accompanying AKI, rather than renal function per se, may play a crucial role.