Cardiac stents have transformed the landscape of cardiovascular medicine, providing a less invasive and highly effective means to treat coronary artery disease.

What is a stent?

A cardiac stent is a small tubelike medical device, typically made of metal (such as stainless steel or cobalt-chromium), or a combination of metal and polymer materials. It is inserted into a narrowed or blocked coronary artery to prop it open and restore normal blood flow to the heart muscle. Stents act as scaffolds, preventing the artery from collapsing back and reducing the risk of recurrent blockages.

When is a stent indicated?

Cardiac stents are indicated primarily in cases of coronary artery disease, a condition where cholesterol plaque build-up narrows the coronary arteries, restricting blood flow to the heart muscle. Stents are recommended when patients experience angina (chest pain) or suffer from heart attacks (myocardial infarctions).

When to consider a stent versus open heart surgery?

Stents offer several advantages over open-heart bypass surgery, such as being less invasive, requiring a shorter recovery period and having a lower risk of complications. It is often preferred for patients with single or double-vessel disease.

Bypass surgery is typically reserved for patients with more complex and multi-vessel coronary disease, or if there are other indications to opening the chest such as a concomitant need to fix a heart valve — then both coronary bypass and valve repair would be done during the same open-heart procedure.

How is a stent delivered inside a coronary artery?

The patient is prepped in a sterile environment, usually in a catheterisation laboratory. She/he is typically awake during the procedure but may be sedated. A small incision is made in the patient's groin or wrist, and a hollow catheter with a guidewire inside it is inserted into the cut blood vessel. The catheter and wire are carefully threaded through the body arteries until they reach the coronary tree.

A contrast dye is injected through the catheter, and X-ray images (angiograms) are taken to visualise the blocked area in the coronary artery (ies).

A deflated balloon is inserted over the guidewire and positioned at the blockage. The balloon is then inflated to compress the plaque or blockage against the artery walls, widening the narrowed artery.

Once the artery is “dilated”, the coronary stent is deployed over the inflated balloon. Subsequently, the balloon is deflated and removed, leaving the expanded stent in place.

Another set of X-ray images is taken to confirm that the stent is properly placed and blood flow has improved through the stent lumen. All support hardware is then removed, and the puncture site in the groin or wrist is typically sealed with a closure device or manual pressure.

What are the different types of stent?

There are two main types of cardiac stents: bare-metal stents and drug-eluting stents. BMSs are plain metal stents that provide structural support to the artery but may lead to restenosis (re-narrowing) in some cases.

DESs are coated with medications that prevent restenosis, making them a popular choice for most patients.

Patients with cardiac stents are often prescribed two antiplatelet medications, typically aspirin and Clopidogrel (Plavix), to prevent blood clot formation inside the stent. The duration of blood-thinning therapy varies depending on the type of stent used and the patient's risk factors, but can range from a few months up to a year or longer.

BM and newer DE stents require shorter blood-thinning duration than “traditional DES”.

What are bioabsorbable stents?

Bioabsorbable stents are an innovative type of stent designed to gradually dissolve and be absorbed by the body over time. These stents are typically made from biocompatible materials, such as polylactic acid or polyglycolic acid, which are commonly used in medical devices.

Bioabsorbable stents have the advantage of not permanently remaining in the body. However, their use is still evolving, and they are not suitable for all patients or all coronary artery lesions.

Can a stent move after successful deployment?

Once deployed, stents are designed to be firmly anchored within the coronary artery. The risk of a stent moving after successful placement is extremely low. Only rare such cases have been reported in the medical literature, usually related to procedural imperfections.

Does a stent need to be replaced?

Stents are designed to be permanent implants and, in most cases, they do not need to be replaced. In rare instances where re-narrowing or other complications arise, additional interventions may be necessary, such as balloon angioplasty or a new stent placement.

Do I need to take antibiotics before dental procedures?

Routine antibiotic prophylaxis before dental procedures and the likes is not required for patients with stents, as the risk of stent infection is extremely low.

Can I get an MRI if I have a stent?

Yes, all types of medical imaging studies including magnetic resonance imaging are possible with stents. No restrictions or special preparation or considerations are generally needed.

Can stents be used in other parts of the body?

Yes, different types and sizes of stents are available for usage across diverse body arteries, mostly in the brain and neck, the aorta, the kidneys and the lower limbs.

• Joe Yammine, MD, is a consultant cardiologist at the Bermuda Hospitals Board. The information here is not intended as medical advice or as a substitute for professional medical opinion. Always seek the advice of your physician