New Devices and Techniques for Coronary CTOs: Will They Change Our Indications?

10.3 / IAGS 2019
Session 10: Coronary Session 3
New Devices and Techniques for Coronary CTOs: Will They Change Our Indications?
Problem Presenter: Emmanouil S. Brilakis, MD, PhD

Statement of problem or issue

The outcomes of coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have significantly improved, with experienced centers currently achieving 85%-90% success with 2%-3% complication rates. However, success rates remain significantly lower (around 60%) at less experienced centers. Moreover, CTO PCI procedures can be long and equipment intensive. The EuroCTO trial demonstrated that CTO-PCI improves symptoms, however DECISION CTO showed no impact on the incidence of major adverse cardiac events, but that trial had multiple limitations. The EXPLORE and REVASC trials did not demonstrate improvement in ejection fraction after CTO-PCI.

Gaps in knowledge

Despite recent studies and advances in equipment, there remain questions about the clinical benefit of CTO-PCI, and uncertainty about how to further optimize the success, efficiency, and safety of the procedure.

Possible solutions and future directions

A large randomized-controlled clinical trial of CTO-PCI vs no CTO-PCI in patients with high ischemic burden and with the primary endpoint defined as the incidence of major adverse events would be ideal, but would require a large sample size. A sham-controlled study could provide more definitive evidence on the symptomatic benefits of CTO-PCI. CTO-PCI studies aiming to improve left ventricular function should enroll patients with baseline left ventricular dysfunction and viable myocardium in the CTO-supplied zone. Standardization of the definitions and the terminology used in CTO-PCI could facilitate performance of future studies and comparisons between studies.

Improving the guidance of CTO-PCI with imaging, such as imaging with computed tomography, could facilitate lesion crossing and thereby improve the safety of the procedure. Development of novel re-entry devices could also facilitate procedures that    involve subintimal guidewire crossing. Evolution of microcatheter and guidewire technology can help overcome anatomic challenges, such as impenetrable proximal caps and collateral vessel tortuosity. Expanding training in CTO-PCI could generate more physicians well prepared to treat such lesions: CTO-PCI and complex PCI in general may be best taught as a subspecialty of interventional cardiology, similar to structural and peripheral interventions.