Abstract 12534: Clinical Impact of Gap Angle Ratio in Patient With Ostial Lesion of Right Coronary Artery Undergoing Percutaneous Coronary Intervention

Abstract

Background: However in drug-eluting stent (DES) era, ostial lesion of right coronary artery (RCA) is associated with high incidence of in-stent restenosis (ISR). And the issue of DES implantation in ostial lesion of RCA has not been adequately evaluated. Objective: The purpose of this study is to investigate the incidence of ISR and the predictive value in patients with ostial lesion of RCA who underwent percutaneous coronary intervention (PCI). Methods: A cohort of 56 patients (73.4±9.9 years-old, 70% male) who underwent PCI for ostial lesion of RCA was retrospectively analyzed in Tokyo Metropolitan Bokutoh hospital from November 2001 to October 2015. We investigated the angle between greater curvature of aortic wall and RCA take-off at diastolic and systolic phase in left anterior oblique (LAO) position view. Clinical outcome was defined as ISR at follow up coronary angiography. We performed receiver operating characteristic analysis for ISR. Results: Incidence of ISR was 41.1% (n=23) in entire patients. Area under the curve of Gap (angle difference between maximum and minimum) / minimum Angle Ratio (GAR-min) for ISR was 0.723 and the cut off value was 0.306 (specificity 0.818, sensitivity 0.696). We divided patients into 2 group; Low GAR group (<0.306: n=35); High GAR group (≥0.306: n=21). There were no significant differences between 2 groups in baseline characteristics. ISR was significantly lower incidence in Low GAR compared with High GAR (22.9% vs. 71.4%, p<0.001). GAR>0.306 was an independent predictor of ISR after adjustment of multiple cofounders (OR: 8.54, 95% CI: 2.18-33.1, p=0.002). Conclusion: These data suggest that High GAR (≥0.306) may predict ISR in patient undergoing PCI to ostial lesion of RCA.