Stent Vs. Bypass Which One Is Better?

Overview

Stent-based percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) are widely accepted treatments for coronary artery disease (CAD).¹ Although PCI is increasingly performed, CABG has traditionally been considered the gold standard of care.²

What is coronary artery disease?

CAD or coronary heart disease (CHD), is often caused by atherosclerosis.

However, the presence of risk factors contributes significantly to the prevalence of CHD, with 3.8 million men and 3.4 million women dying from CHD each year.

Therefore, there is an urgent need to reduce mortality while improving quality of life through prevention, early detection, and appropriate management of CHD.⁶

Understanding stenting and bypass surgery 

What is stenting?

PCI refers to a minimally invasive procedure that is used to open blocked coronary arteries (arteries that carry blood to the heart). Restoring blood flow can improve symptoms of arterial blockage, such as chest pain and shortness of breath.

Highly qualified and experienced interventional cardiologists can use PCI to repair the most complex coronary artery occlusions, even chronic total occlusions.³

An older term for PCI is coronary angioplasty with stent placement, or angioplasty for short. Arteries are blood vessels that carry oxygen-rich blood from the heart to the rest of the body. A PCI procedure uses a small balloon to open a blocked artery and increase blood flow.

An interventional cardiologist then usually places a small permanent tube (stent) to keep the artery open for a long time. Stents usually contain drugs that are released directly into the artery (drug-eluting stents), reducing the risk of restenosis within the artery.

Who needs percutaneous coronary intervention?

A PCI procedure may be required to remove a buildup of thick, greasy material called plaque from your arteries. Atherosclerosis is a condition where plaque builds up and hardens in arteries.

Atherosclerosis increases the risk of cardiovascular disease and blocks blood flow to the heart. Chest pain (angina pectoris) can occur when the heart cannot pump blood efficiently. Healthcare providers can also use PCI to treat heart attacks. PCI opens blood vessels quickly to help minimise damage to the heart.

Who should not undergo percutaneous coronary intervention?

It depends on several factors such as:

• The number and characteristics of blockages you have
• Other cardiac and non-cardiac diseases
• Heart muscle function and age⁴

  Stent types

• Bare metal stent (BMS) - Preferred when patients cannot tolerate  take extended longer periods of dual antiplatelet therapy (DAPT). At least 1 month of DAPT is required after BMS placement
• Drug Eluting Stent (DES) - Lower rates of restenosis and revascularization have been found in individuals with DES compared to BMS
• Bioabsorbable Vascular Scaffold (BVS)
• Drug Eluting Balloon (DEB)⁵

What is bypass surgery?

Coronary artery bypass grafting (CABG) is a major surgical procedure that uses a harvested venous or arterial line to bypass an atheromatous occlusion in a patient's coronary arteries.

Bypass restores blood flow to heart muscles that lack blood supply (ischemic myocardium), improves the function and viability of the heart, and relieves symptoms of angina.

In general, on-pump and off-pump are two types of  CABG surgical procedures, with the difference being that inon-pump CABG, a cardiopulmonary bypass circuit and cardiac arrest are used.

Conduits used as bypass grafts are usually the left internal mammary artery (LIMA) and saphenous veingrafts (SVG) from the lower extremities. Other vessels that can be implanted include the right internal mammary artery (RIMA), the radial artery, and the gastroepiploic artery. A LIMA is usually implanted in the left anterior descending artery (LAD) and other conduits are used for other occluded arteries.⁷

Other names for coronary artery bypass graft surgery:

• Bypass surgery
• Coronary artery bypass surgery
• Heart bypass surgery

Who needs a coronary artery bypass graft?

Coronary artery bypass graft (CABG) surgery is only used to treat people with severe coronary artery disease, which can lead to heart attacks.

Doctors may recommend CABG when other treatments, such as lifestyle changes and medications, do not work. 

CABG may be recommended if the large coronary arteries that supply most of the heart muscle are severely blocked, especially if the heart's pumping ability is already weak.

CABG is also a treatment option when there is a heart blockage that cannot be treated with angioplasty.

Your doctor will determine if you are a candidate for  CABG based on many factors. This includes the presence and severity of CHD symptoms, severity and location of the coronary artery occlusion, response to other treatments, quality of life, and other medical issues.

Deciding which one is better: stent vs. bypass

Many factors are considered in determining which procedure is safer and more effective. Both procedures can cause complications. This includes:

• Heart attack
• Irregular heart rhythm (arrhythmia)troke

When diagnosed with CHD, an interventional cardiologist will consider:

• The severity of CAD
• Number of vessels in need of repair
• Whether a drug has already been tried
• Presence or history of other conditions such as diabetes, arrhythmia or previous heart attack¹⁰

Stenting: pros and cons

What are the advantages of percutaneous coronary intervention?

PCI improves blood flow to the heart. It can relieve symptoms of blocked arteries, such as:

• Chest pain
• Shortness of breath (dyspnea)

What are the risks or complications of percutaneous coronary intervention?

All cardiac treatments have risks. The risks after PCI include:

• Bleeding or infection at the catheter insertion site
• Cardiac stent thrombosis
• Arterial restenosis 
• Stroke⁴

Bypass surgery: pros and cons

The procedure has several advantages, some of which are especially beneficial for individuals with severe cardiovascular disease. 

Elective coronary bypass surgery is very efficient at removing or lessening discomfort if you experiences persistent angina and shortness of breath due to damaged heart arteries. Overall, a coronary bypass operation can restore your life.

When compared to elective surgeries for the treatment of angina and other symptoms, the risk of major consequences is higher for emergency coronary bypass procedures, such as those done in patients who are experiencing a heart attack. 

The risk may also be higher for those with other severe illnesses such as diabetes, peripheral vascular disease, kidney disease, or lung disease.

While there are still some problems that can occur after coronary bypass surgery, your care team will do everything possible to prevent and treat them if they do arise. 

They might consist of the following:

• Risk of bleeding from the site of attached graft and other sources
• Heart rhythm problems 
• Blood clots 
• Infection at the incision site where the chest was opened for surgery 
• Post-pericardiotomy syndrome 
• Kidney (renal) failure
• Memory loss or difficulty thinking 
• Allergic reactions to anesthesia 
• Death - In-hospital death is very rare after coronary bypass surgery. It is typically caused by heart attack or stroke⁹

Stenting vs. CABG

Stenting                                                                            

• Minimally invasive
• Preferred for emergencies
• Not useful in all CAD cases
• Faster recovery

CABG

• Invasive
• Preferred for severe cases and multiple blockages
• More complete revascularisation¹⁰

Summary

CAD  can be treated with medical treatments (drugs) or procedures such as stent placement or bypass surgery. Determining the best treatment option is an individualised process.

In the non-emergency treatment of CHD, both treatments can help significantly to reduce symptoms. In general, non-urgent revascularisation with either method does not improve survival.

However, both stent placement and CABG may improve outcomes for patients with acute coronary syndrome. This term describes an acute heart condition, such as a heart attack. Both procedures can improve patient outcomes in the following situations:

• Complex lesions of multiple coronary arteries
• Disorders of the left main coronary artery (which supplies the heart with the most blood)

In emergencies, stent placement is usually preferred over CABG. Acute ST-elevation myocardial infarction (STEMI) is the most dangerous form of heart attack. If you have this type of heart attack, angioplasty can save your life.

Because angioplasty is less invasive, it is usually easier to recover from it than from CABG.

If coronary artery disease is severe, your healthcare provider may recommend CABG. CABG is thought to improve long-term outcomes in patients with multivessel CAD. This is a severe CAD that affects all three major coronary arteries. Also, a diabetic patient tends to have a better outcome after CABG surgery than after stent placement.

In some circumstances, CABG may be required instead of angioplasty. For example, if the blood vessels are very weak and diseasedor if the anatomy of the arteries is unusually complex.

Overall, CABG is usually considered a more complete treatment than stent placement.¹⁰