Renal Function, OCT-Defined Coronary Calcification and Stent Optimization in Optical Coherence Tomography-Guided Percutaneous Coronary Intervention: A Single-Center Cross-Sectional Study

Background: Reduced renal function is linked to coronary calcification, which can limit stent expansion, and to contrast-associated acute kidney injury (CI-AKI). We examined renal function, optical coherence tomography (OCT)-defined calcification and OCT measures of stent optimization in a Vietnamese provincial hospital. Methods: This prospective, single-center, cross-sectional study included consecutive patients undergoing OCT-guided percutaneous coronary intervention (December 2023 to January 2026). eGFR was calculated with the CKD-EPI 2021 equation and CI-AKI defined by KDIGO creatinine criteria. Lesion-level associations were estimated by logistic or linear regression with patient-clustered robust standard errors, before and after adjustment for age, sex, diabetes, hypertension, smoking and acute coronary syndrome. Results: The cohort comprised 300 patients, 309 procedures and 356 lesions. Mean eGFR was 79.7 ± 20.7 mL/min/1.73 m 2 and 60 procedures (19.4%) had eGFR < 60. Calcification was present in 235 lesions (66.0%). Each 10 mL/min/1.73 m 2 lower eGFR was associated with calcification in unadjusted analysis (OR 1.19; 95% CI 1.03– 1.38), but not after adjustment including age (OR 1.04; 0.88– 1.22), whereas age remained associated (OR 1.46 per 10 years; 1.09– 1.95). Mean minimum stent area was 5.75 ± 2.26 mm 2 and was not correlated with eGFR ( ρ =0.05; P=0.36); stent expansion ≥ 80% (87.4%) and procedural success (88.7%) were not associated with eGFR in crude or adjusted models. CI-AKI occurred in 8 of 206 procedures with paired creatinine (3.9%). Subgroups with eGFR < 45 (22 lesions) and < 30 (7 lesions) were small, and these analyses were exploratory. Conclusion: In this single-center cross-sectional study, the crude association between lower eGFR and OCT-defined calcification was largely explained by age. Under OCT guidance, renal function was not associated with stent optimization, and CI-AKI was infrequent. Prospective studies with larger advanced-CKD populations and a comparator arm are needed to establish whether OCT guidance offsets renal-related procedural disadvantage.