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Coronary artery disease is the development of “atherosclerotic plaques” on the walls of the coronary arteries, that is, the arteries that carry blood to the heart.

These plaques affect the function and diameter of the coronary artery lumen.

Most of the time, these changes occur imperceptibly over time. And while initially, the sufferer may feel few symptoms, such as atypical discomfort, the increase in the degree of coronary artery stenosis is accompanied by more intense symptoms, such as pain, shortness of breath, and easy fatigue.

Coronary artery disease affects a large part of the population, and based on the latest measurements from the World Health Organization, 29.6% of deaths worldwide are due to cardiovascular disease (the leading cause of death).

The main risk factors for developing the disease, apart from old age, are:

• Heredity
• Smoking
• High blood pressure
• Diabetes mellitus
• Hypercholesterolemia
• Poor diet
• Lack of physical exercise.

From coronary artery stenosis to chronic total occlusions:

Prevention and regular check-ups are the cornerstones for treating coronary artery disease.

In this context, timely intervention with appropriate health and dietary measures (smoking cessation – proper nutrition – avoiding obesity – physical exercise, etc.) and appropriate medication (antihypertensives – hypolipidemics – antidiabetic drugs, etc.) if required, bring about the primary arrest of the evolving vascular changes.

As the treatment of symptoms by a specialist is delayed, the vascular changes gradually progress, leading to acute conditions (unstable angina – myocardial infarction), in which the treatment beyond medication is now the reperfusion of the coronary arteries either invasively (percutaneous balloon angioplasty and stent) or surgically (coronary artery by-pass grafting, CABG).

What happens, however, if the symptoms worsen, but the patient tolerates them even if they make their quality of life difficult? During this period, more and more calcified atheromatous plaques are created, which dramatically reduce the diameter of the vessels, limiting the amount of blood passing through.

This condition may affect more than one vessel at the same time. When the narrowed lumen is completely blocked, for a period of more than three months and does not allow blood to pass through in a straight line, it is called CHRONIC TOTAL OCCLUSION (CTO).

In this case, the part of the myocardium that is irrigated by the chronically occluded artery is in a “hibernating” state (hibernating myocardium), as it is supplied by collateral branches of another coronary artery. The blood flow from collateral branches is sufficient to keep it alive, but it is unable to meet its needs during exercise.

When oxygen consumption exceeds supply, pain, called angina, occurs. This is a direct indication for opening of the CTO.

New developments in the treatment of Chronic Total Coronary Occlusions:

The presence of CTO is associated with an increased frequency of symptoms (angina pectoris, heart failure), and the possibility of death or other cardiovascular complications in the future. Large studies have shown that reperfusion of CTOs in some categories of patients reduces symptoms and improves quality of life.

According to the until recently valid Guidelines of the major Cardiology Societies (American – European), CTOs were only treated surgically in patients undergoing myocardial reperfusion with Coronary Artery By Pass Grafting (CABG).

Today, with the advancement of technology and the availability of specially manufactured materials for the purpose, it is possible to open CTOs percutaneously, that is, by inserting catheters through the arm and/or leg, without requiring a sternotomy as is the case with bypass.

Opening CTOs is an extremely demanding procedure and is considered the “Holy Grail” of Interventional Cardiology. It is performed using special microcatheters, Intravascular Ultrasound (IVUS) and rotational atherectomy and shockwave balloon lithotripsy are often used.

A prerequisite is a thorough understanding of the characteristics of the atherosclerotic plaque and the collateral branches to access the occlusion. Patients undergo a detailed clinical examination and imaging with Cardiac Magnetic Resonance Imaging (CMR).

The patient arrives at the hospital on the morning of the operation. General anesthesia is not required and in the hands of an experienced and properly trained team, the complications of the operation remain very low. Then, he remains for observation overnight, before being discharged the very next day of the operation.

Specialization and Organized Hospital Structures:

Based on the above, it is perfectly understandable that percutaneous interventions for the treatment of Chronic Total Coronary Artery Occlusions require a high degree of specialization, modern hospital logistical equipment and the availability of appropriate materials.

At the Athens Medical Center, within the Second Cardiology Clinic, the Department of Complex Coronary Artery Disease and CTOs has recently started operating.

This Department is able to treat even the most technically demanding cases of coronary artery disease. Before each operation, patients with CTO are assessed by the “Heart Team” of the Second Cardiology Clinic and the most beneficial therapeutic strategy for each patient is selected using strict scientific criteria, with the main focus on the expected benefit in relation to the possible risks of the operation.

70-year-old patient for angioplasty of chronic total occlusion of a large labial branch, due to symptoms of angina, after unsuccessful attempts to open it.

In the categorization of the degree of difficulty, this specific lesion is classified as the most difficult CTO (J-CTO score 3). The operation was successfully performed through the radial artery.