Impact of Chronic Kidney Disease on Contrast-Induced Nephropathy, Bleeding, and Clinical Outcomes After Rotational Atherectomy: A Multicenter Retrospective Study

<i>Background and Objectives</i>: Chronic kidney disease (CKD) is associated with severe coronary calcification and increased procedural risks. We aimed to evaluate the impact of CKD on contrast-induced nephropathy (CIN), bleeding, and clinical outcomes in patients undergoing rotational atherectomy (RA). <i>Materials and Methods</i>: This study retrospectively analyzed 652 patients who underwent RA for calcified coronary lesions from the multicenter ROCK registry and a single-center extension between 2010 and 2025. Patients were classified into CKD (eGFR < 60 mL/min/1.73 m², <i>n</i> = 66) and non-CKD (<i>n</i> = 586) groups, excluding those on dialysis. The primary endpoint was a composite of CIN and in-hospital bleeding. Secondary endpoints included 3-year target vessel failure (TVF), myocardial infarction (MI), and total bleeding. <i>Results</i>: The primary composite outcome occurred more frequently in the CKD group (16.7% vs. 5.1%, <i>p</i> = 0.001). Specifically, CIN was significantly higher in CKD patients (15.2% vs. 1.7%, <i>p</i> < 0.001), while in-hospital bleeding did not differ significantly. In multivariate analysis, CKD was an independent predictor of the primary outcome (adjusted OR 3.02; 95% CI 1.36-6.69; <i>p</i> = 0.006). At 3-year follow-up, total bleeding (10.6% vs. 3.9%, <i>p</i> = 0.008) and MI (6.1% vs. 2.1%, <i>p</i> = 0.024) were higher in the CKD group, whereas TVF and cardiac death showed no significant difference. <i>Conclusions</i>: CKD is a robust independent risk factor for CIN and long-term bleeding in patients undergoing RA. However, comparable clinical efficacy outcomes suggest that RA remains a feasible strategy in CKD patients when early complications are carefully managed with contrast-minimizing strategies.