What should you know about coronary stents…
After your cardiologist has performed an angioplasty and opened the critically blocked coronary artery, it is important to see that the artery doesn’t get blocked again. A coronary stent is an important device which is used to keep the handled artery patent.
Once it is proven that the blockages in the coronary artery are significant enough to cause symptoms, a percutaneous coronary intervention or PCI can be performed to insert a stent after the angioplasty. Your cardiologist might perform an intravascular Ultrasound or IUS examination with a highly specialized device. With this, the cardiologist can evaluate the hardness and calcification in the blood vessel. This can help us assess the feasibility of the intervention.
Different types of Coronary Stents:
Stents are scaffolds that help in keeping the artery open. They may be used in any clinical situation requiring PCI.
There are different types of coronary stents. The most basic stent is a bare metal stent or BMS.It is possible that the body recognizes the stent as a foreign body and over the time, ironically, an adverse response may be seen in the vessel where there is an immune response and tissue proliferates around the stent. This proliferation can in turn causes re-blockage or restenosis of the artery. Advances have taken place and these stents are coated with certain medications which reduce the complication of proliferation and re-stenosis if not totally prevent it. These are called drug eluting stents or DES.
There are a number of factors involved in deciding whether and which stent is actually needed. Whether it is BMS or DES they can be used depending on patient and lesion under consideration. (Both elective angioplasty of primary and rescue angioplasty after a heart attack)
Importance of antiplatelet Therapy:
In-stent restenosis is a limitation of all stents. It is an immune mediated response where the healing of the vessel wall after placement of the stent is exaggerated. The risk is 30 to 50 % in case of BMS and lesser i.e. 5 to 10 % for DES.
After a coronary stent is placed, the restenosis risk is of utmost concern. Therefore a combination of antiplatelet therapy is prescribed.It is pertinent that patient takes dual anti platelet therapy for the prescribed period (usually 6-12 months).
These tablets prevent clots being formed in the stent suddenly.
Not taking it missing can have serious consequences like heart attack or death.
By the end of the year, our own tissues will cover the stent; hence antiplatelet therapy can be modified as per the cardiologists advice.
Until recently a combination of antiplatelet agents Aspirin and Clopidogrel were prescribed for a year after the intervention, which was then tapered down to a single drug. With time, newer antiplatelet agents have been developed which could serve the purpose better.
In-stent restenosis cannot be prevented by any medicines including cholesterol or anti platelet medicines.The usual time period is 3-12 months. This may mean a repeat procedure or bypass surgery. However, if In-stent restenosis does not develop but the end of the year, then usually the stented segment remains fine for life.
Usually any elective surgery which necessitates the stoppage of antiplatelet drugs should be avoided within one year after the intervention. Sincere antiplatelet therapy is the cornerstone of preventing a subacute thrrombosis.
After the blockage in the artery is handled, it is also important to prevent the stenosis of the part of the artery which is not supported with a stent. This needs lifestyle management and regression of risk factors aggressively.
Coronary stents are thus a novel way to salvage the suffering heart. No doubt the heart takes some time to accommodate this foreign savior, the stent eventually remains as a permanent family member in the family.