A stent is a tiny, mesh-like tube often made of a metallic alloy or polymer, designed to be inserted into a narrowed bodily passage, such as an artery, to keep it open and maintain blood flow. These small, expandable devices act as a scaffold, propping open vessels constricted by plaque buildup in conditions like atherosclerosis. While traditional stents are simply metal, drug-eluting stents represent an advancement. These advanced stents are coated with medication that is slowly released into the artery wall.
How Drug Eluting Stents Work
Drug-eluting stents (DES) consist of a metal scaffold, often made of a cobalt-chromium or platinum-chromium alloy, and a polymer coating. This coating serves as a controlled-release system for specific medications. The polymer slowly releases an antiproliferative drug, such as sirolimus or paclitaxel, directly into the surrounding artery wall.
The medication’s primary function is to inhibit neointimal hyperplasia, which is the excessive growth of smooth muscle cells within the artery. After a stent is placed, the body naturally reacts to the foreign material, which can lead to an overgrowth of these cells and re-narrow the artery around or within the stent. By releasing the drug, the DES effectively prevents these cells from multiplying and migrating into the stented area. This localized delivery of medication helps to maintain the vessel’s open diameter, ensuring sustained blood flow.
Why Drug Eluting Stents Are Preferred
Before drug-eluting stents, bare metal stents (BMS) were the standard treatment for opening blocked arteries. While BMS successfully provided immediate mechanical support to keep arteries open, a significant limitation was the high rate of restenosis, or re-narrowing. This re-narrowing occurred within months after implantation, primarily due to the body’s natural healing response causing excessive tissue growth inside the stent.
Drug-eluting stents significantly address this issue by incorporating a drug that suppresses unwanted cell proliferation. Clinical trials have shown that DES significantly reduce the incidence of restenosis compared to bare metal stents, lowering re-narrowing rates to less than 5%, with BMS rates as high as 30%. This reduction in re-blockage translates to improved long-term outcomes for patients, minimizing the need for repeat procedures and reducing the risk of adverse cardiac events like heart attacks.
Living with a Drug Eluting Stent
After the implantation of a drug-eluting stent, adhering to a specific medication regimen is important to prevent complications. Patients are prescribed dual antiplatelet therapy (DAPT), which includes aspirin and a P2Y12 inhibitor. This medication combination is important because the foreign material of the stent and its drug coating can increase the risk of blood clot formation, known as stent thrombosis.
These antiplatelet medications work by preventing platelets from sticking together and forming clots on the stent surface, ensuring blood flows smoothly through the newly opened artery. The duration of DAPT varies depending on individual risk factors, but it commonly ranges from six months to a year or more following DES implantation. Consistent adherence to this medication schedule is important, as prematurely stopping these drugs can increase the risk of complications, including stent thrombosis, which can lead to a heart attack or stroke.
Regular follow-up appointments with healthcare providers are important when living with a drug-eluting stent. These visits allow doctors to monitor the stent’s function, assess cardiovascular health, and adjust medications as needed. Adopting heart-healthy lifestyle modifications, such as maintaining a balanced diet, engaging in regular physical activity, managing blood pressure and cholesterol levels, and quitting smoking, supports the long-term success of the stent and overall well-being.