Chronic Total Occlusion Revascularization (CTO) & Percutaneous Coronary Intervention (PCI)

Why does CTO revascularization need specialized expertise?

For regular or standard PCI procedures, the interventional cardiologists access the heart through a catheter (small tube) inserted through a skin puncture. The majority of coronary blockages allows some blood to flow through the vessel. Crossing a wire to deliver equipment through the narrowed artery is, most of the times, not difficult. In contrast, if the patient has a CTO, this means that the vessel has been completely blocked for quite some time. To deliver devices, the interventional cardiologist needs to create a pathway through or around the blockage. As such, opening a CTO requires a combination of specialized devices and techniques, including: 

  • Double arterial access, in either wrist or groin, for optimized visualization of the occluded vessel. 
  • Using specialized wires to puncture and cross the complete blockage. 
  • Navigating the wire around the blockage through the vessel wall and then going back into the vessel. 
  • Going backwards through tiny bypasses (collateral channels) that arise from non-blocked coronaries. These collaterals are naturally created by the body to bring blood and keep alive the muscle supplied by the blocked vessel. 

These techniques can be performed alone or in combination. The ability to perform all of them further increases the likelihood of success. At the London Health Sciences Centre, we have the complete set of expertise and devices to perform all the above-mentioned techniques. 

Who should have CTO PCI?

In the presence of a CTO, an area of the heart muscle does not receive enough blood supply. As a result, the patient may experience chest pain (angina), shortness of breath or even a heart attack. These symptoms occur with exertion and sometimes at rest. 

Individuals with CTOs may experience the following symptoms: 

  • Chest pain, pressure or tightness (angina pectoris) 
  • Shortness of breath that usually worsens with activity 
  • Dizziness 
  • Fatigue 
  • Pain in the upper body and arm 
  • Jaw pain 
  • Certain patients may also have depression and a decreased quality of life. 

Importantly, medications are the primary treatment for every patient who has a CTO. Patients should initially be treated with tablets to check if those alone are sufficient to alleviate their symptoms. However, if symptoms do not improve, opening the CTO can be considered to improve the patient’s quality of life. Indeed, the main objective of CTO PCI is symptom control, and this can be noticeable within days or weeks of the procedure. Studies have shown an improvement in quality of life after the procedure, including: 

  • Reduced chest pain (angina) 
  • Reduced shortness of breath 
  • Increase in physical activity 
  • Decrease in feelings of depression 
  • Higher levels of energy 

The Procedure

Before the procedure, two interventional cardiologists specially trained for this type of intervention review the images and the information about the patient’s condition. 

The procedure usually takes 2-4 hours depending on the complexity of the intervention and the patient is usually awake. In about 10-15% of the cases, a second session is required, often scheduled after 6-8 weeks, to fully and optimally open the blockages. Occasionally, patients need to be monitored during an overnight stay in the hospital. 

Typically, two catheters (tubes) are placed in both wrists, although for more complex blockages, more catheters may be inserted, and the groins may also be used. After the procedure, the catheters are removed. 

In specialized centers like ours, the overall success rate is close to 90%, but it is realistic to expect that some cases are more challenging than others. 

How safe is the procedure?

CTO PCI and routine PCI have similar complications, although they are more common in CTO PCI. These may include: 

  • bleeding at the puncture site (arm or groin) 
  • kidney damage (usually temporary) 
  • allergy to contrast dye or medications 
  • heart attack 
  • damage to the arteries or the heart itself 

Specific risks of the procedure, possible hurdles that may be encountered, as well as potential benefits for each patient are carefully reviewed prior to the procedure and discussed with the patient. At any time before or during the procedure, if the team detects that the risk may outweigh the benefits, the procedure is interrupted or not even performed.