Optical coherence tomography–defined radial artery calcification: frequency, phenotypes, and correlates in a retrospective transradial PCI cohort

Background and aims The frequency, distribution, and optical coherence tomography (OCT) features of radial artery calcification (RAC) remain poorly defined. We assessed OCT-defined RAC and factors associated with patient-level RAC. Methods This single-center retrospective observational study included 461 patients with analyzable radial artery OCT (RA-OCT) between January 2021 and August 2025. RAC was assessed at the patient, segment, and lesion levels. Clinical characteristics, radial artery plaque features, coronary OCT findings, and factors associated with patient-level RAC were evaluated. Results Among 461 patients in the final analytic cohort, OCT-defined RAC was identified in 61 (13.2%). RAC involved the proximal, middle, and distal segments in 17/461 (3.7%), 25/461 (5.4%), and 52/461 (11.3%) patients, respectively. Among 214 calcified lesions, spotty calcification was the most common morphology (151/214, 70.6%). In exploratory patient-level analyses, all five radial artery plaque features were associated with RAC after multivariable adjustment, and all associations remained significant after Benjamini–Hochberg false discovery rate correction. In multivariable analysis, older age, diabetes mellitus, and coronary calcific nodule remained associated with RAC, whereas coronary calcium score was not statistically associated with RAC after adjustment. Conclusions In this cohort, OCT-defined RAC was identified in 13.2% of patients, was more frequent in the distal segment, and showed heterogeneous lesion-level phenotypes. Older age, diabetes mellitus, and coronary calcific nodule were associated with RAC. Exploratory analyses also showed associations between RAC and multiple noncalcified radial artery plaque features.