Longitudinal Wire Bias Pattern on Intravascular Ultrasound as an Independent Predictor of Coronary Artery Injury During Orbital Atherectomy for Calcified Nodules: A Single-Center Retrospective Study.

Background: Calcified nodules (CN) are a challenging coronary lesion subset often treated with orbital atherectomy (OA), which, although effective, carries a risk of coronary artery injury (CAI), including hematoma and perforation. In this study we assessed the relationship between intravascular ultrasound (IVUS) findings, particularly the wire bias pattern, and CAI during OA for CN. Methods and Results: We retrospectively analyzed 67 patients with CN who underwent IVUS-guided percutaneous coronary intervention with OA between August 2020 and August 2023. The primary endpoint was CAI, defined as hematoma or perforation. IVUS findings, including tenting sign, undesirable wire position, and a newly classified wire bias pattern (Types A-D), were evaluated. 9 patients (13.4%) developed CAI: 8 hematomas (11.9%) and 1 perforation (1.5%). Type D wire bias showed the highest incidence of CAI (47.1%, P<0.001). Multivariate logistic regression identified Type D as the sole independent predictor of CAI (odds ratio 22.43; 95% confidence interval 2.61-192.9; P=0.005). Neither tenting sign nor undesirable wire position was significantly associated. Conclusions: A Type D wire bias pattern on IVUS (defined as the guidewire tracking along the healthy vessel wall proximal and distal to the CN) was an independent predictor of CAI during OA. Preprocedural identification of this pattern may improve risk stratification and procedural strategies to minimize complications.