Percutaneous Transluminal Coronary Arteriography

Article Author:
Kristen Brown
Article Editor:
Nagendra Gupta
Updated:
2/22/2019 5:02:42 PM
PubMed Link:
Percutaneous Transluminal Coronary Arteriography

Introduction

Atherosclerosis causes coronary artery disease (CAD) leading to obstruction of these vessels. Atherosclerosis affects approximately 1 in every 13 Americans aged 18 years and older and approximately 85% of deaths in people 65 years of age and older are secondary to CAD.

Percutaneous transluminal coronary arteriography is the most reliable means of investigating and quantifying the severity of coronary artery occlusive disease. Percutaneous transluminal coronary arteriography is a diagnostic procedure using fluoroscopic images of catheter delivery of contrast dye. The dye travels through the patent vessels and shows up on fluoroscopy as a depiction of the inner blood vessels.

This procedure was first performed in the 1920s, and it ultimately led to the development of percutaneous transluminal coronary angioplasty (PTCA), also known as balloon angioplasty or coronary angioplasty which is a transcatheter treatment procedure that restores blood flow in the coronary arteries identified by arteriography. It is also known by other names such as percutaneous transluminal angioplasty (PTA) or percutaneous transluminal coronary angioplasty (PTCA) or percutaneous coronary intervention (PCI).

Balloon angioplasty has become the method of choice to treat patients with acute myocardial infarction or occluded leg arteries. 

Anatomy

The coronary arteries are tiny blood vessels that transport and deliver oxygenated, nutrient-rich blood to the muscle of the heart. They are mainly composed of the left and right coronary (RCA) arteries that each have branches. The left coronary artery gives rise to the left circumflex (LCx) and left anterior descending (LAD) arteries which both supply the left-side of the heart. The right coronary artery gives rise to the right marginal artery and posterior descending artery (PDA) which mostly supplies the right-side of the heart. 

The right coronary artery as the name suggests supplies the right atrium, right ventricle, the sinoatrial node, and atrioventricular nodes of the heart. The left coronary arteriole system supplies the left atrium and ventricle. As these vessels develop a blockage, loss in the muscle's function or nodes supplied may occur leading to serious adverse events.

PTCA was designed to open up these blockages hoping to restore blood supply and cardiac function.  

Indications

The following are indications for PTCA if the patient is not a candidate for CABG:

  • Acute ST-elevation myocardial infarction (STEMI) [class 1, level A]
  • Non ST-elevation myocardial infarction (NSTEMI) [class 1, level A]
  • Unstable angina [class IIa, level B]
  • Stable angina [class IIa, level B]
  • Anginal equivalent [class IIa, level B]
  • High-risk stress testing [class IIa, level B]

Contraindications

The main contraindication for percutaneous transluminal arteriography is kidney dysfunction with serum creatinine greater than 3. The contrast dye used during the procedure puts these patients at increased risk for worsening renal function as well as an end-stage renal disease requiring future dialysis. 

Equipment

A well equipped, adequately staffed Cath Lab is the essential prerequisite for the success of the procedure.

Personnel

A team made up of a trained interventional cardiologist, a registered nurse, cardiac cath lab technician is required to perform this procedure accurately and safely. Each team member must be certified and prepared for many years in the PTCA technique. 

Preparation

Thorough medication reconciliation should be done before the procedure. If the patient is not already on aspirin 81 mg, they should be started on it. Guidelines also recommend initiation of P2Y12 inhibitors before PTCA. 

The diabetic medication metformin is held before cardiac catheterization to avoid worsening renal insufficiency and lactic acidosis.

Food and drink are restricted for at least 6-8 hours before the procedure to reduce the risk for aspiration. However, sometimes this is not feasible. If the patient requires an emergent catheterization, the procedure should not be postponed due to recent oral intake.

When cases are performed via radial artery access, patients are often given an intra-arterial calcium channel blocker, nitroglycerin, and heparin to prevent vasospasm.

The health care provider should also thoroughly explain the procedure and its associated risks and complications to the patient to obtain a signed informed consent.

Technique

The first step for PTCA is to gain access.

There are multiple access points available including the radial, femoral, and ulnar arteries. Radial access is now the preferred access point as it has lower rates of complications. However, the femoral approach is still done quite often in patients with end-stage renal disease to preserve future access points for dialysis.

A needle is inserted into the chosen artery for access. A guide-wire is then passed through the needle and into the arterial system up to the heart. Using real-time fluoroscopy, a flexible catheter is slipped over the wire and guided up to the heart. At this point, the guide-wire is removed, and the tip of the catheter is positioned to enter the coronary artery.

Contrast dye is then injected into the opening of the coronary arteries. Fluoroscopy is then used to provide the real-time radiographic images of the coronary arteries. Several different views are used to capture all the coronary arteries. These views include LAO cranial view, LAO caudal (aka spider view), RAO cranial view, and RAO caudal view.

Blockages less than 2 mm or smaller than the catheter are considered by many operators, not to be candidates for ballooning. Once the blockage is identified and determined to be safe for PTCA, a flexible guide-wire is threaded through the catheter and up to the heart. The flexible catheter is removed, and the guide-wire is advanced into the blocked coronary artery. A balloon-tipped catheter is then inserted over the guide-wire and positioned at the site of the blockage. Inflation and deflation of the catheter balloon push the artery wall out reestablishing the flow of blood in the artery. Each time the balloon is re-inflated, it blows up a little further. This procedure is done in stages to ensure the artery wall will not dissect.

Once the arterial flow is re-established, the balloon-tipped catheter is removed. The treatment procedure is repeated in case there are multiple blockages. Some patients may require a stent, called coronary stent angioplasty. The stent is a small tube made of wire mesh designed to keep the arteries open. A collapsed stent is placed over a deflated balloon catheter and positioned at the site of the blockage. The balloon catheter is then inflated which expands the stent until it locks in place. Then the deflated balloon and catheter are withdrawn. They are leaving the stent behind to hold the artery open. Most coronary angioplasty procedures last between 30 minutes to 3 hours. Once the process is completed, a pressure bandage is placed over the access site to prevent hemorrhage and hematoma. If femoral access were used, the patient would need to lay flat for several hours during which time the signs of bleeding or chest pain are monitored. Most patients can return home the same day as the procedure. 

Complications

Multiple studies following PTCA have revealed an increased risk of new-onset arrhythmias, angina, aneurysm, arteritis, coronary artery aneurysm, congestive heart failure, renal failure, groin infection, myocardial infarction, hemorrhage, hematoma, thrombus, pancreatitis, and death to be possible complications of percutaneous transluminal coronary angioplasty. [1] [2] [3] In 1994 Carey and colleagues studied the need for emergency surgical intervention following PCTA complications and found that postoperative complications were higher in the former PCTA  group with stroke and arrhythmias. [4]  In 1996, White and colleagues published a study that showed a strong association between coronary thrombus and post-operative complications following PTCA. [5]

Clinical Significance

The advent of the percutaneous transluminal arteriography was a monumental turning point in Cardiology. It offered patients a nonsurgical method of treating coronary artery disease. 

Enhancing Healthcare Team Outcomes

Percutaneous transluminal arteriography (PCTA) is a minor procedure but can be connected with many serious complications. A Heart Team approach [level 1] [6]  is recommended and the ideal way to limit the complexities of this procedure. Before the intervention, the patient should have the following done:

  • Preoperative evaluation including a thorough physical examination and electrocardiogram (ECG)
  • Timely stress testing with either exercise or chemical stress testing if appropriate.
  • Pre-procedure imaging including an echocardiogram to assess the structure and function of the heart.
  • Pre-procedure evaluation by Anesthesiologist to ensure that the patient is fit for general anesthesia.

References

[1] White HD,Reynolds HR,Carvalho AC,Pearte CA,Liu L,Martin CE,Knatterud GL,D┼żavík V,Kruk M,Steg PG,Cantor WJ,Menon V,Lamas GA,Hochman JS, Reinfarction after percutaneous coronary intervention or medical management using the universal definition in patients with total occlusion after myocardial infarction: results from long-term follow-up of the Occluded Artery Trial (OAT) cohort. American heart journal. 2012 Apr;     [PubMed PMID: 22520521]
[2] Lee AH,White L,Gallagher PJ,Dawkins KD, Acute arteritis after coronary angioplasty. American heart journal. 1992 Aug;     [PubMed PMID: 1636597]
[3] Dimarco RF,McKeating JA,Pellegrini RV,Marrangoni AG,Bekoe S,Grant KJ,Woelfel GF, Contraindications for percutaneous transluminal coronary angioplasty in treatment of unstable angina pectoris. Texas Heart Institute journal. 1988;     [PubMed PMID: 15227244]
[4] Carey JA,Davies SW,Balcon R,Layton C,Magee P,Rothman MT,Timmis AD,Wright JE,Walesby RK, Emergency surgical revascularisation for coronary angioplasty complications. British heart journal. 1994 Nov;     [PubMed PMID: 7818959]
[5] White CJ,Ramee SR,Collins TJ,Escobar AE,Karsan A,Shaw D,Jain SP,Bass TA,Heuser RR,Teirstein PS,Bonan R,Walter PD,Smalling RW, Coronary thrombi increase PTCA risk. Angioscopy as a clinical tool. Circulation. 1996 Jan 15;     [PubMed PMID: 8548896]
[6] Sanchez CE,Dota A,Badhwar V,Kliner D,Smith AJ,Chu D,Toma C,Wei L,Marroquin OC,Schindler J,Lee JS,Mulukutla SR, Revascularization heart team recommendations as an adjunct to appropriate use criteria for coronary revascularization in patients with complex coronary artery disease. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography     [PubMed PMID: 26527352]