Brief Review of Drug-eluting Stents

What is a Stent?

What do you think of when you hear the word, stent? Do you picture the small metal mesh that is put into some patients with heart problems? You wouldn't be wrong. These bare-metal stents are what textbooks depict. I was shocked to learn that doctors don't use these much anymore. I only recently learned about the drug-eluting stent (DES). If you are like me and have never heard of DESs, or are looking for a quick refresher, you have come to the right place.

Stents are used to keep an artery open after it has been narrowed by plaque (coronary artery disease or CAD). This again allows enough blood to get to the heart, providing the oxygen and nutrients the cardiac cells need to continue to work.

Research has shown that about 40 percent of those who have angioplasty without a stent are confronted with restenosis or the recurrence of a narrowing artery after corrective surgery. This usually happens 6 months after the first operation. Normally, as the body heals from the procedure, healthy cells grow. Later, scar tissue forms underneath those healthy cells. Sometimes the scar tissue is so thick that it blocks the blood flow. Other times the scar tissue allows for new plaque buildup, leading to restenosis.

Bare-metal stents reduce the odds of that occurring. If used in angioplasty, the percentage of restenosis decreases to 25. The healthy cells and scar tissue form underneath the newly placed stent, and restenosis follows.

What is a DES?

DESs were created in the 2000s to solve some of the issues with bare-metal stents. They are very similar to bare-metal stents but have a key difference.

As you might guess from the name, DESs slowly release medication into the artery. The medication aids in preventing the formation of scar tissue and blood clots. When using a DES with angioplasty, the percentage of restenosis is reduced to below 10.

DESs used to be made in different ways. One was made of material similar to dissolving stitches. It would elute medication and completely dissolve in 3 years. At first, this was thought to be better, but clinical trials showed they caused more complications.

Risks of DESs

Today, doctors use DESs approved by the FDA. When paired with anti-clotting medication, DESs are safe and work well for many people. Like all things medical, there is always a possible risk.

Possible risks of DESs include:

• Allergic reaction to the dye
• Allergic artery closure
• Blood clots
• Coronary artery closure
• Coronary artery rupture
• Damage to blood vessels due to the catheter
• Infection
• Irregular heart rhythm
• Stroke

Patients need to consider a few things before getting a DES. Things to consider are:

• Do the patient's medications need to change?
  • Medications such as aspirin can affect surgeries, medical procedures, and other medications. If the patient cannot delay a noncardiac surgery, they need to talk to their doctor about the medications they are taking. Dosages may need to be changed.
• Does the patient need to have another type of surgery soon?
  • If they are considering having another surgery within a year of the proposed angioplasty, they may need to postpone it for a year. If they cannot, a bare-metal stent might be a better option.

Benefits of DESs

DESs provide the same benefits as other stents, plus they reduce the risk of restenosis. The benefits of getting a DES include:

• Prevention of plaque formation
• Increased blood flow to the heart
• Decreased angina
• Decreased chances of heart attack/failure

Insertion of a stent is much easier than having coronary bypass surgery. Recovery time is shorter. Those who have a DES inserted recover in a few days while those with a coronary bypass surgery can take six weeks plus to recover.

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References

Restenosis: Repeat Narrowing of a Coronary Artery

Drug-eluting stents: Do they increase heart attack risk?: Mayo Clinic

Drug-eluting stents: How do they work?: Healthline

What to know about drug-eluting stents: WebMD