Fluoroscopic Percutaneous Coronary Interventions, Assessment, Protocols, and Interpretation

Anatomy and Physiology

The heart is Supplied by Three Major Coronary Arteries

1. Left anterior descending with Septal and diagonal branches
2. Left circumflex artery
3. The right coronary artery bifurcates into the right posterior descending artery and right posterior left ventricular branch.

However, in a patient with a previous history of coronary artery bypass graft, grafts are placed distal to the narrowed segment of the coronary artery. The most commonly used vessels for grafts are saphenous vein graft, left internal mammary artery, right internal mammary artery, radial artery, gastroepiploic artery, and inferior epigastric artery. It is essential to know the site and number of grafts before the graft study.

Indications

2011, ACCF/AHA/SCAI Guideline for Percutaneous Coronary Intervention

Indications of percutaneous coronary intervention to improve mortality:[5]

• In unprotected left main artery with ST-elevation myocardial infarction: If distal flow to vessel less than TIMI III and percutaneous coronary intervention can be done much quicker and safer than CABG (Class II-a)
• In unprotected left main artery with non-ST-elevation myocardial infarction or Unstable angina: If CABG can not be performed (Class II-a)
• In unprotected left main artery with stable ischemic heart disease: If two of the following present 1) LOW-risk PCI (Syntax<22) and ostial or trunk involvement 2) Increase risk of surgical adverse events ( STS score < 5 (Class II-a)
• In triple vessel coronary artery disease with or without Proximal LAD: (Class II-a)
• In two-vessel disease with proximal LAD: (Class II-b)
• In two-vessel disease without proximal LAD: (Class II-b)
• In one vessel disease with proximal LAD: (Class II-b)
• For patients with the survivor of sudden cardiac death with presumed ischemia-mediated ventricular tachycardia (Class I)

Indications of percutaneous coronary intervention to improve symptoms:

• Percutaneous coronary intervention in patients with persistent angina despite optimal medical management to improve symptoms with single or more significant (>70% diameter) coronary artery disease and amenable to revascularization. (Class I)
• Percutaneous coronary intervention in patients with persistent angina to improve symptoms with single or more significant (>70% diameter) coronary artery disease and medical management can not be given because of medication contraindication, adverse effects, or patient preferences. (Class II-a)
• Percutaneous coronary intervention in patients with persistent angina despite optimal medical management to improve symptoms with single or more significant (>70% diameter) coronary artery disease and associated with ischemia. (Class II-a)

Contraindications

The following are the contraindications of percutaneous coronary intervention 

Absolute Contraindication

1. Intolerance to dual antiplatelets
2. Severe illness which reducing the lifespan to less than one year

Relative Contraindication

1. Coronary artery vessel diameter < 2.5 mm
2. Anatomy not feasible for coronary intervention
3. Diffusely disease saphenous vein graft

Equipment

For fluoroscopic percutaneous coronary intervention, the following equipment is essential:

• Fluoroscopic machine
• Contrast agent
• Guide catheters
• Guide wires
• Coronary balloon
• Coronary stent

To prevent radiation exposure during the fluoroscopic guided percutaneous coronary intervention, each medical staff require protective measure during the procedure which includes:

• Lead apron
• Thyroid collar
• Radiation protective glasses
• Radiation monitoring badges

Personnel

• Intervention cardiologist
• Radiation technician
• Cath lab technician
• Staff nurse

Preparation

Informed consent should be taken before the procedure. It is essential to take a complete history and perform a physical examination pre-procedure to determine the indication of the procedure. The patient should be premedicated with antiplatelets.

Technique or Treatment

It is essential to know in which view a specific part of the artery will be visible while performing coronary angioplasty under fluoroscopic guidance.[6][7]

Images are shown before and after the percutaneous coronary intervention of RCA.

Complications

Following are the complications associated with the percutaneous coronary intervention.

1. Coronary artery dissection
2. Coronary artery perforation
3. Distal embolization of clot
4. Side branch occlusion
5. Stent thrombosis
6. Access site bleeding
7. Access site hematoma
8. Acute kidney injury
9. Stroke
10. Allergic reaction to contrast

Following are the complications associated with fluoroscopic radiation exposure to patients or staff.[8]

Tissue Reaction

• Skin Injury: It is the most common tissue reaction at the beam entry site following fluoroscopic guided percutaneous coronary intervention and varies according to time of exposure:

1. Few hours  to days of post-exposure: Mild skin erythema
2. A week to several weeks of post-exposure: Significant erythema
3. After 4 to 8 weeks of post-exposure: Severe skin injury including ulceration in rare cases

• Bone Injury: In rare cases, radiation can cause necrosis of superficial bones such as ribs.
• Eye Injury: The single-dose threshold of radiation that can cause a cataract to believe to be 500 mGy with a minimum latency period of one year.

Stochastic Effects: Radiation-Induced Cancer

It is the most important and catastrophic result of radiation exposure. It is vital to provide knowledge of the scholastic risk of radiation exposure to both patients and healthcare workers. These steps are necessary to reduce the risk, which includes the use of radiation protection instruments.

Clinical Significance

Fluoroscopic percutaneous coronary intervention is a widely performed procedure for the last several years. In comparison to thrombolysis, percutaneous coronary intervention reduces morbidity and mortality significantly in patients with myocardial infarction. In chronic coronary syndrome patients, it has proven to improve the quality of life. Compared to CABG, it is associated with a shorter hospital stay, no scar on the chest, and early mobilization after the procedure. Because of advancement in percutaneous coronary intervention over time, survival improvement in patients with coronary artery disease was noted.

Enhancing Healthcare Team Outcomes

Fluoroscopic percutaneous coronary intervention requires an interprofessional team including an intervention cardiologist, cath lab technician, radiation technician, and staff nurse. To improve outcomes, good collaboration among team members is essential. It is vital that every team member should be aware of their roles to avoid complications.

Nursing, Allied Health, and Interprofessional Team Interventions

The nursing staff gives medications and monitors vitals during the procedure. The radiographic technician set views on the fluoroscopy machine for the procedure and supports performing procedures such as intravascular imaging and invasive physiological assessment. The cath lab technician prepares equipment such as a coronary balloon, coronary stent and guides catheters for the procedure.