Don’t stop medication prematurely
Patients who have had drug-eluting stents inserted to prop open blocked coronary arteries should continue to take medications to reduce the risk of blood clots for at least one year after the stent is inserted, a new scientific research revealed.
A coronary stent is a wire mesh tube used to open a blocked artery to the heart. The stent stays in the artery permanently, helping to hold it open, which improves blood flow to the heart muscle and relieves chest pain.
Drug-eluting stents are coated with medication which is slowly released to reduce the risk of having stenosis or blockage of that artery for a second time.
The medication named Clopidogrel and Aspirin are known as antiplatelet agents (which inhibit clotting factor platelet aggregation and prevent blood clot formation).
These drugs should be administered before stent insertion to reduce the chance of clotting within the stent, which may result in heart attack or death.
This dual antiplatelet therapy, which is shown to be most effective for preventing stent thrombosis (blood clots), particularly true for patients receiving drug-eluting stents, with the risk of thrombosis remaining high for at least one year after receiving a drug-coated stent, as compared with six months for bare metal stents. Despite this benefit, antiplatelet therapy is sometimes discontinued prematurely within the first year of stenting.
This practice is potentially deadly. Stopping antiplatelet therapy too early after a stenting is the leading independent factor causing stent thrombosis (blood clotting or blocking inside a stent by a mass of coagulated blood) that frequently lead to heart attacks or may cause even death.
Death rates due to presumed or documented stent thrombosis range from 20 percent to 45 percent. Every patients and healthcare professionals should consider it with great concern.
They should not even think about stopping antiplatelet therapy as it may steal their life. If any healthcare professional feels that stopping these medicines is absolutely necessary, the patient's cardiologist should be consulted, and the medications should be start over as soon as possible. Physician may advise to postpone elective procedures if the patient experiences discomfortable with continuing antiplatelet medication.
Drug-eluting stents act by preventing the tissue growth that causes arteries to re-narrow (restenosis); therefore, a person will be less likely to need repeated angioplasty or bypass surgery.
They also may cause harm. If tissue growth is reduced, it indicates the stent is exposed to the blood for a longer time, which increases the risk of forming blood clot.
Research showed that stent thrombosis was up to 29 percent among patients who discontinued antiplatelet therapy early.
Patients should receive appropriate antiplatelet therapy according to existing practice guidelines wherever possible. This will usually require patients taking both Aspirin and Clopidogrel for periods of up to at least one year after stenting.
Several factors lead patients to stop taking clopidogrel early. These include 1) cost of the drug, 2) surgeon's or dentist's instructions before surgery to prevent bleeding during procedure, and 3) inadequate patient education and patient understanding of the importance of taking the medicine.
The following points should be consider carefully:
- • Before implanting a stent, the physician should discuss the need for antiplatelet therapy with the patient. In patients are expected not to comply with 12 months of clopidogrel therapy, for any reason, a bare metal stent should be considered.
- In patients who are likely to require surgery within 12 months of receiving a stent, a bare metal stent or balloon angioplasty with a provisional stent should be an alternative of routinely using a drug-eluting stent.
- Healthcare professionals must make a greater effort to educate patients before hospital discharge. They should provide counseling about the reasons for prescribing clopidogrel, benefits of taking the dual antiplatelet therapy, as well as the risks if they stop early.
- Patients should be specifically instructed to contact their cardiologist before stopping any antiplatelet therapy, even if instructed to do so by another healthcare professional.
- Healthcare providers who perform invasive or surgical procedures should be made aware of the potentially catastrophic risks of prematurely stopping antiplatelet therapy, and should contact the patient's cardiologist to discuss optimal patient management.
- Elective procedures that carry a risk of bleeding should be delayed until a month after the patient has completed an appropriate course of clopidogrel therapy, which is ideally 12 months after receiving a drug-eluting stent in patients who are not at high risk of bleeding, and at least six month after a bare metal stent.
- For patients who receive a drug-eluting stent and who must have procedures that dictate stopping clopidogrel, aspirin should be continued if at all possible, and the clopidogrel should be restarted as soon as possible after the procedure.
The writer is an Assistant Professor of Cardiology at BSMMU & Fellow, Interventional Cardiology at Max Heart & Vascular Institute, New Delhi, India.
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