Role of Coronary Computed Tomography Angiography in Percutaneous Coronary Intervention of Chronic Total Occlusions

Abstract

Despite significant advances in procedural techniques for revascularization of chronic total occlusions (CTO), comprehensive procedural planning and accurate prediction of procedural success remain the Achilles’ heels of CTO percutaneous coronary intervention (PCI). Understanding the unique anatomic characteristics of CTOs that may predict relative success and complication rates of revascularization is imperative. Coronary computed tomography angiography (CCTA) has evolved as an adjunct to invasive angiography to better characterize CTO lesions to improve success rates of CTO PCI. Invasive angiography may be inadequate to characterize CTOs due to its inability to fully visualize the occluded segment. CCTA has evolved as a valuable adjunct to angiography, as it permits imaging of the arterial wall in the absence of luminal contrast, and thereby provides additional information regarding both the vessel course and lesion characteristics. CCTA-derived data can also be used in either standalone or combined scoring systems to assess the difficulty level of CTO PCI and has been shown to predict procedural success in clinical trials. Real-time CT fusion with X-ray angiography provides intraprocedural guidance to help resolve proximal cap ambiguity and better determine vessel course. In this review, we discuss the role of CCTA in guiding and improving outcomes of CTO PCI, both pre-procedurally and in real time.