Chronic Total Occlusion (CTO)

Chronic total occlusion (CTO) is a blockage in the coronary artery, which has been present for more than three months. A complication of coronary artery disease, CTOs result from severe build-up of fatty deposits or plaque within the coronary arteries and are one of the most challenging lesions to treat.

Symptoms of chronic total occlusion may include:

  • Chest pain (angina)
  • Fatigue
  • Faintness
  • Upper body pain
  • Irregular heart beat

While traditional treatment has entailed coronary artery bypass grafting (CABG), open-heart surgery, a less invasive procedure known as percutaneous coronary intervention (PCI) is proving effective in patients not considered good candidates for traditional surgical repair.

Multiple studies show that success in opening CTOs is largely dependent on the experience of the operator among other factors. In experienced hands, the success rate can be over 90 percent [1,2].


  1. Kearney K, Hira RS, Riley RF, Kalyanasundaram A, Lombardi WL. Update on the Management of Chronic Total Occlusions in Coronary Artery Disease. Curr Atheroscler Rep. 2017 Apr;19(4):19. doi: 10.1007/s11883-017-0655-0.
  2. Heuser RR. Support with a Twist: New Approaches in CTOs and Complex Lesions. J Cardiol Cases. 2017 Oct 4;17(1):12-15. doi: 10.1016/j.jccase.2017.08.013. eCollection 2018 Jan.