CTO PCI: treatment for a completely blocked heart artery

What is a chronic total occlusion?

A chronic total occlusion (CTO) is a coronary artery that has been completely blocked for three months or longer. The blockage is usually made of hardened cholesterol plaque and scar tissue built up over many years.

CTOs are common. They are found in roughly one in five people who have a coronary angiogram for known or suspected coronary artery disease. Many people are surprised to learn they have one, because the heart often grows small natural bypass vessels, called collaterals, that partly supply the muscle beyond the blockage.

Collaterals keep the heart muscle alive, but they rarely supply enough blood when you exert yourself. That is why a CTO can cause angina or breathlessness even if you have never had a heart attack.

Symptoms

Some people have no symptoms. In that case treatment is not usually needed, unless tests show a large area of the heart is short of blood.

Treatment options

There are three main approaches. The right one depends on your symptoms, the anatomy of your arteries, how well your heart pumps and your other health conditions. Many patients do best with a combination.

Decisions about complex cases are often discussed in a heart team meeting with cardiac surgeons, so you receive a balanced recommendation.

Who benefits from CTO PCI?

The strongest evidence for CTO PCI is for relieving symptoms and improving quality of life. In randomised trials, patients who had their CTO opened reported less angina and better physical function than those treated with medicines alone.

You are more likely to benefit if:

• you have angina or breathlessness that limits your daily life despite medicines
• scans (such as cardiac MRI, stress echo or nuclear imaging) show the heart muscle beyond the blockage is alive and short of blood
• the CTO is the main untreated problem in your arteries

Before recommending the procedure, I review your angiogram in detail and usually arrange a scan to confirm that opening the artery is likely to help.

How the procedure works

CTO PCI uses the same basic approach as a standard angioplasty, but needs specialist equipment and techniques because a CTO is fully closed and often hard and long.

1. Mapping the blockage. Thin tubes are placed through arteries in both wrists or the groin. Dye is injected into both sides of the heart at once so the whole blockage and the collaterals beyond it can be seen.
2. Crossing the blockage. Specialist guidewires are steered through or around the occlusion. There are three main strategies, and switching between them during the procedure is standard practice:
   • Antegrade wiring: working forwards through the blockage in the direction of blood flow.
   • Dissection and re-entry: passing a wire alongside the blockage within the artery wall, then re-entering the channel beyond it.
   • Retrograde approach: reaching the far end of the blockage through collateral vessels or bypass grafts and working backwards.
3. Imaging from inside the artery. Intravascular ultrasound (IVUS) or optical coherence tomography (OCT) is used to guide wire position and choose the right stent size.
4. Stenting. The channel is widened with balloons and held open with drug-eluting stents, which release medication to reduce the chance of re-narrowing.

In large international registries of experienced centres, this hybrid approach opens the blocked artery in around 85–90% of cases.

On the day

• Anaesthetic: local anaesthetic with light sedation. You are comfortable but awake.
• Duration: typically two to three hours, sometimes longer.
• Hospital stay: most patients are discharged the same day, some stay overnight.
• Medicines: you will take blood-thinning tablets beforehand and for a period afterwards. Do not stop these without speaking to your cardiologist.
• Where: Royal Papworth Hospital

Risks

CTO PCI carries a higher risk than standard angioplasty because the procedures are longer and more technically demanding. In large international registries, serious complications occur in around 2–3% of procedures. These include:

• perforation of the artery, which can cause bleeding around the heart and occasionally needs emergency drainage or surgery
• heart attack during or shortly after the procedure
• stroke (uncommon)
• death (under 1%)

Less serious risks include bruising or bleeding at the wrist or groin, kidney strain from the X-ray dye, and skin redness from the radiation used during long procedures.

We will go through your individual risk in detail before you decide. For many people the risk is lower than these averages; for others, such as those with previous bypass surgery or very complex blockages, it may be higher.

Recovery

• Driving: DVLA guidance for car and motorcycle licences is not to drive for at least one week after a successful planned angioplasty. You do not need to tell the DVLA. Bus and lorry licence holders must notify the DVLA.
• Work: most people return to desk-based work within about a week. Manual jobs may need longer.
• Exercise: avoid heavy lifting and strenuous activity for around a week while the puncture sites heal, then build up gradually. Cardiac rehabilitation is recommended.
• Follow-up: a clinic review to check symptoms and adjust medicines.

Many patients notice an improvement in their exercise capacity within weeks.

Second opinions

If you have been told your blocked artery cannot be treated with a stent, or that a previous attempt was unsuccessful, a review by a CTO specialist can be worthwhile. Success rates are closely linked to operator experience and to the specialist equipment available.

For a second opinion, please send copies of your angiogram images (usually on a CD or via an image-sharing link) and any recent letters or scan reports to my secretary before your appointment.