Remote ischemic preconditioning reduces contrast-induced nephropathy in patients undergoing coronary angiography or percutaneous coronary intervention: an updated meta-analysis of randomized controlled trials

Background Contrast-induced nephropathy (CIN) is a common complication following coronary angiography (CA) or percutaneous coronary intervention (PCI) and is associated with prolonged hospitalization and adverse clinical outcomes. Remote ischemic preconditioning (RIPC), a noninvasive and nonpharmacological intervention, has been proposed as a potential strategy for preventing CIN. However, evidence from randomized controlled trials (RCTs) remains inconsistent. Methods This meta-analysis of RCTs aimed to evaluate the efficacy of RIPC for preventing CIN in patients undergoing CA or PCI. The primary outcome was the incidence of CIN. For dichotomous outcomes, risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using the Mantel–Haenszel fixed-effect model. For continuous outcomes, standardized mean differences (SMDs) with 95% CIs were pooled using a fixed-effect model when heterogeneity was low and a random-effects model when substantial heterogeneity was present. Trial sequential analysis was performed for dichotomous outcomes to estimate the robustness of the cumulative evidence and the required information size. This study was prospectively registered with PROSPERO (CRD420251269657). Results Twenty-six RCTs including 4,169 participants were included. Overall, RIPC significantly reduced the risk of CIN compared with the control treatment (RR 0.49, 95% CI 0.41–0.59, P  I 2  = 0%). Regarding renal function, RIPC significantly attenuated postprocedural increases in serum creatinine levels (SMD −1.00, 95% CI −1.60 to −0.39, P  = 0.001) and was associated with lower postprocedural serum creatinine levels (SMD −0.23, 95% CI −0.39 to −0.08, P  = 0.003). RIPC was also associated with a lower risk of major adverse events (MAEs) (RR 0.55, 95% CI 0.41–0.75, P  = 0.0001). No significant differences were observed in postprocedural eGFR, neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, all-cause mortality, dialysis requirement, or rehospitalization. Conclusion In patients undergoing coronary angiography or percutaneous coronary intervention, RIPC was associated with reduced risks of CIN and MAEs, attenuated postprocedural increases in serum creatinine levels, and lower postprocedural serum creatinine levels, while evidence for postprocedural eGFR, NGAL, cystatin C, and clinical outcomes remains inconclusive. Systematic Review Registration https://www.crd.york.ac.uk/PROSPERO/view/CRD420251269657 , PROSPERO CRD420251269657.