Analysis of Risk Factors for Contrast-Induced Acute Kidney Injury after PCI in Elderly Patients with Mild to Moderate Renal Insufficiency

Background Contrast-induced acute Kidney Injury (CI-AKI) is a significant complication that can occur after percutaneous coronary intervention (PCI), particularly in patients with pre-existing renal insufficiency. The study was carried out to investigate the main risk factors for CI-AKI in elderly people diagnosed with mild to moderate renal insufficiency undergoing PCI. Method An observational study. Clinical data were collected from 200 patients aged ≥ 60 with a glomerular filtration rate lower than 90 ml/min who underwent PCI surgery. Based on the occurrence of postoperative acute kidney injury (AKI), patients were divided into an AKI group and a non-AKI group to analyse and identify the main risk factors for CI-AKI. Results Analyses from clinical variables indicated that more elderly patients developed postoperative AKI. These include patients who used diuretics and angiotensin receptor-neprilysin inhibitors (ARNI) more frequently and received higher doses of contrast agents (all at P  < 0.05), all of which may increase the risk of AKI. Age-stratified analysis revealed no significant difference in age between AKI and non-AKI patients within each group. Also, laboratory results showed that AKI patients had significantly higher creatinine levels both at baseline and post-operative stages. Further analyses confirmed that while these indices are essential in identifying the risks of AKI, they lack adequate robustness and should better be considered alongside other clinical factors for accurate diagnosis. Conclusion This study discovered that older age, frequent usage of diuretics and ARNI, and the administration of higher contrast agent doses are key risk factors for postoperative AKI.