Workflow of the study protocol.

<div><p>We developed a comprehensive kidney protection strategy (KPS), which comprises left ventricular end-diastolic pressure-guided saline hydration, ultralow contrast coronary angiography, and a staged coronary revascularization procedure under suitable conditions. This study aimed to investigate KPS’s effect on the risk of developing contrast-associated acute kidney injury (CA-AKI) among persons with moderate-to-advanced kidney insufficiency (KI). Seventy patients who had undergone cardiac catheterization with an estimated glomerular filtration rate (eGFR) of 15–45 mL/min/1.73 m<sup>2</sup> were investigated retrospectively. Among these, 19 patients who had received KPS and 51 who had undergone cardiac catheterization with usual care (UC) were enrolled. CA-AKI was defined as a 0.3-mg/dL increase in serum creatinine levels or dialysis initiation within 72 h after contrast exposure. The inverse probability of treatment weighting (IPTW)-adjusted cohort was analyzed according to the Mehran 2 risk categories. Patients’ mean age was 73.3 ± 9.6 years; mean eGFR was 29.8 ± 8.5 mL/min/1.73 m<sup>2</sup>; and median of Mehran 2 risk score, 8. Most patients presented with acute myocardial infarction (AMI) or heart failure, and one-fifth of the administered cardiac catheterizations were emergency procedures. After the IPTW adjustment, the KPS group showed a significantly lower CA-AKI risk than the UC group (4% vs. 20.4%; odds ratio 0.19, 95% confidence interval 0.05–0.66). This effect was consistent across various subgroups according to different variables, including old age, AMI, advanced KI, high-risk category, left ventricular systolic dysfunction, and multivessel disease. Conclusively, KPS may reduce the CA-AKI risk in high-risk patients with moderate-to-advanced KI who have undergone cardiac catheterization.</p></div>