Zero- and Ultra-Low-Contrast Percutaneous Coronary Intervention Versus Conventional PCI in Advanced Chronic Kidney Disease: A Systematic Review and Meta-Analysis

Introduction: Advanced chronic kidney disease (CKD) patients undergoing percutaneous coronary intervention (PCI) face a high risk of renal injury. Given this vulnerability, zero- and ultra-low-contrast PCI techniques have been proposed to minimize renal damage while still enabling effective revascularization. On this basis, this meta-analysis tests whether these contrast-sparing strategies yield better clinical and renal outcomes compared with conventional PCI in CKD patients. Methods: A total of 3939 records were retrieved from PubMed, Embase, Scopus, ScienceDirect, and Cochrane from inception till November 2025. Eligible RCTs and comparative observational studies reporting renal or cardiovascular outcomes were included. Pooled analyses were conducted in RevMan Web using a random-effects model with p < 0.05 considered statistically significant. Results: Across nine included studies (464,815 patients) evaluating zero-contrast or ultra-low-contrast PCI versus conventional PCI, zero-contrast PCI significantly reduced contrast-induced acute kidney injury (CI-AKI) (OR 0.24, 95% CI 0.12–0.49; p = 0.002), decreased contrast volume (MD −110 mL, 95% CI −168.6 to −51.8; p = 0.005), lowered the need for repeat revascularization (OR 0.26, 95% CI 0.09–0.77; p = 0.005), and reduced the incidence of emergent hemodialysis (OR 0.25, 95% CI 0.13–0.49; p < 0.0001). All-cause mortality and repeat myocardial infarction were initially nonsignificant but became significant after excluding outlier studies (OR 0.49, 95% CI 0.47–0.51; p < 0.00001; OR 0.19, 95% CI 0.10–0.35; p = 0.007, respectively). No significant differences were observed for major adverse cardiovascular events, cardiovascular or non-cardiovascular mortality, renal replacement therapy, or dialysis requirement. Conclusions: Our findings demonstrate that zero- and ultra-low-contrast PCI significantly reduces the risk of CI-AKI while preserving cardiovascular and renal outcomes, supporting its use as a safe and effective alternative to conventional PCI in high-risk CKD patients.