“Coronary artery disease” is the narrowing or blockage of the coronary arteries which is mainly caused by atherosclerosis. Atherosclerosis, known as hardening of the arteries, is the buildup of cholesterol and fatty deposits called “atherosclerotic plaques” on the inner walls of the arteries. The obstruction of coronary arteries decreases blood flow to the heart. Eventually, the reduced blood flow may cause angina (or chest pain) and shortness of breath. A complete blockage can result in a fatal heart attack.

Risk factors of coronary artery disease  

• High blood cholesterol increases the chances of plaque formation and uncontrolled high blood pressure (hypertension) can result in hardening and thickening of the arteries leading to narrowing or obstructed channel through which blood can circulate.
• Smoking. The chemical substances found in cigarette such as nicotine and carbon monoxide stimulate heart rates and increase risks of platelet aggregation, leading to cardiovascular events. Smoking significantly increases risk of heart disease up to 24%. Exposing others to secondhand smoke also increases risks of coronary artery disease.
• Diabetes is strongly associated with an increased risk, up to doubled, of coronary artery disease.

If coronary arteries narrow, the ability to circulate blood is impaired. As a consequence, oxygen-rich blood cannot be sufficiently supplied to the heart. The warning signs including chest pain or shortness of breath are subsequently presented, especially when the heart beats hard such as during exercise.
 

Diagnosis and treatment of coronary artery disease

The main procedure primarily used to diagnose and treat coronary artery disease is called “cardiac catheterization” This procedure clearly visualizes blood flow through the heart. During performing cardiac catheterization, special dye will be injected into coronary arteries (known as an angiogram) through a long, thin, flexible tube (catheter) that is threaded through an artery usually in the leg, wrist, arm or neck. It eventually approaches the arteries in the heart. After reaching the arteries, the dye outlines narrow areas and blockages on the displayed X-ray images. If a blockage has been found and it requires treatment, a balloon and a mesh tube (stent) can be subsequently used.
 
The most common site for arterial access is femoral artery in the groin of the leg. Due to its larger diameter, a catheter can be inserted quite easily. However, the wound site (catheter insertion site) in the groin highly needs special care. Post-procedural complications may include hematoma (localized bleeding outside of blood vessels) and active bleeding. After the procedure is completely performed, patients must lie flat, refraining from bending the affected leg for 2 up to 6 hours.  Owning to the fact that femoral artery approach for cardiac catheterization has some limitations, to access artery safely, cardiac surgeons have been identifying another site which is “radial artery at the wrist” with fewer complications and improved treatment outcomes.
 

Transradial Cardiac Catheterization

Transradial cardiac catheterization is a procedure used to diagnose and treat coronary artery disease. During the procedure, a long thin tube (catheter) is inserted through the radial artery which is a blood vessel in the arm. A catheter is then threaded through the blood vessels all the way to the heart with image guidance of special X-rays. Transradial cardiac catheterization can be performed at both left or right wrists with no differences. Although, in comparison with femoral artery in the groin,  the radial artery in the arm is considerably smaller with more complicated route until reaching the heart, the advancements in medical equipment used for transradial catheterization helps improving treatment outcome which is notably equivalent to femoral artery access.
 
As an alternative with high degree of safety and fewer complications for treatment of coronary artery disease, transradial artery approach has been widely used. After the procedure, without highly special restrictions, patients are able to continue their daily activities such as having meal and going to the toilet. Even though the transradial artery access is safe and effective in most circumstances, it must be performed by highly experienced and well-trained cardiologists. In addition, the selected procedure is largely dependent on unique medical and personal circumstances of individual patients. Transradial catheterization is preferred choice for obese patients or patients with  peripheral artery disease (circulatory problem in which narrowed arteries reduce blood flow to the limbs). Nevertheless, radial artery might be reserved for other treatments such as hemodialysis or coronary artery bypass grafting (CABG). In such a case, femoral artery access is an appropriate option.
 
Recently, the treatment of coronary artery disease has been dramatically evolved in terms of treatment procedures and medical equipment as well as cutting edge technology. Transradial cardiac catheterization is an increasingly used technique and has been widely recognized as an effective option due to a faster recovery time and shorter hospital stay. However, patients with coronary artery disease might have different circumstances and disease severity. The blockage of vessel could be visualized as a single point or multiple areas. Therefore, the appropriate treatment with the best possible outcomes for individual patients must be carefully selected.
 

Advantages of transradial cardiac catheterization  

• Reduced risks of serious complications that might cause from femoral artery access.
• Decreased the length of hospital stay without movement restriction after procedure is completed.
• Fewer local complications due to smaller blood vessel. Its superficial location allows blood to be quickly stopped in case of bleeding. If active bleeding in the leg is presented during or after femoral artery access, blood transfusion might be required. This could also lead to aneurysm (weakening and bulging of an artery wall) and surgery might be additionally needed, resulting in a longer hospitalization period and impaired movement ability.

 
Appropriate treatment must be selected for individual patients 

Selecting the right treatment for each patient while taking personal conditions into consideration plays a major role to build confidence among patients. The essential process for making effective and safe treatment plan involves a grading system that evaluates the complexity and prognosis of patients with coronary artery disease, called The SYNTAX Score.
 
Step 1: Cardiologists fully investigate the abnormalities by using QCA (Quantitative Coronary Analysis) to visualize the degree of stenosis in all affected vessels. All relevant diagnostic parameters and tools must be well analyzed in order to plan treatment accurately and effectively.
 
Step 2: Fractional Flow Reserve (FFR) is used to identify whether the blockage of the vessel needs further treatment. It is a guide wire-based procedure that can accurately measure blood pressure and flow through a specific part of the coronary artery. It determines the pressure differences between the origin of stenosis (site A) to the ending part (site B). The obtained result indicates the sufficiency of blood flow to the heart. For example, FFR value less than 0.8 means that the stenosis or blockage needs to be dilated and it will increase blood supply to heart up to 20%. Since this parameter significantly enhances treatment accuracy, in a very near future, Bangkok Heart Hospital will be implementing the combined approached between step 1 and step 2, known as QFR: Quantitative Flow Ratio.
 
Step 3: Cardiologists evaluate stenosis level together with presented clinical symptoms. If the stenosis is indicated in 1-2 vessels and SYNTAX score is fairly low, additional treatment with balloon to dilate affected vessels is highly considered. For more severe cases of multiple stenosis (more than 2-3 vessels) with high SYNTAX score and multiple stent implantation is required, patients must be treated by multidisciplinary team for advanced treatment such as coronary artery bypass grafting (CABG).

Not only providing comprehensive heart care to all patients, Bangkok Heart Hospital is committed to conduct clinical research involving in highly complicated heart conditions such as chronic coronary artery disease and other forms of stenosis. To obtain the best possible treatment outcomes, stent optimization technique is used to precisely measure the diameter of affected vessels by using a catheter. As a result, stent can be accurately placed with full dilation ability. Effective treatment can be additionally provided with the support of echocardiography, high frequency catheter and transesophageal echocardiogram. All patients can rest assured that they always receive appropriate, timely and safe treatments by using the international standards of American College of Cardiology (ACC) and Society of Cardiac Angiography and Coronary Intervention (SCAI).