Chronic Total Occlusion Anatomy and Characteristics of Coronary Collaterals and Angiographic Features Predicting the Success of Chronic Total Occlusion Intervention

Abstract

Background and Objective: Angiographic assessment of chronic total occlusion (CTO) anatomy and collateral characteristics of coronary arteries are necessary for CTO intervention. Materials and Methods: This was a hospital-based observational study of 100 coronary angiograms (CAG) with CTOs. CTO anatomy and collateral characteristics of coronary arteries were studied for predicting anterograde and retrograde CTO intervention. Results: Right coronary artery (RCA) CTO was the most common (62%), followed by left anterior descending (LAD). More than two-thirds of RCA and LAD CTO lesions were >20 mm and half were in mid-segment. Left circumflex artery (LCX) and RCA lesions were more frequently calcified. LAD CTOs often had blunt stump; LCX CTOs frequently had bending >45°. The mean J-CTO score was lowest in RCA CTOs (2.0 ± 1.19). There were 10 different types of collaterals in RCA CTOs, 8 in LAD CTOs, and only 4 in LCX CTOs. The most common RCA CTOs collateral was LAD septal to the right posterior descending artery (RPDA) (69.4%) and in LAD CTOs, the most common was septal collaterals from the RPDA to LAD (40.9%). RCA CTOs had a higher percentage of septal collaterals, less tortuosity, and favorable entry and exit angle when compared with other two arteries. Conclusion: RCA CTOs were the most common. Angiographic features in CTO lesions vary among three major coronary arteries. The RCA CTOs had lesser mean J-CTO score, more number of septal collaterals, less tortuous collaterals, and favorable entry and exit angle. RCA CTOs were better accessible for anterograde and retrograde intervention.

Keywords

• chronic total occlusion
• coronary calcification
• coronary collaterals
• coronary intervention
• right coronary artery