Life-saving medical advances are often coupled with life threatening risks. Advancement in heart attack prevention is no exception and can prove to be particularly dangerous. The limited nature of clinical trials combined with complex financial incentives has led to yet another promising, but often deadly, product in drug coated stents.
A stent is an expandable wire mess tube, about the size of the spring inside a ballpoint pen, which is inserted into an artery that has been cleared of fatty deposits to keep it open and prevent future heart attacks. They are often used as an alternative to bypass surgery.
Bare metal stents can cause restenosis, the formation of scar tissue which narrows the artery and restricts blood flow. If restenosis progresses enough, the patient must undergo revascularization to open the artery.
Drug coated stents were developed to prevent restenosis. The drug coating which discourages the formation of scar tissue, slows the healing process. The stent is not covered by scar tissue as it normally would be and this causes the body to treat it as a foreign object. Red blood cells and platelets begin to stick to the inside of the stent and form a blood clot. The process is called late thrombosis and causes a heart attack or cardiac arrest about 70% of the time.
The use of anti-clotting drugs can significantly reduce the risk of late stent thrombosis, but anti-clotting drugs are expensive and carry their own dangers. Stopping anti-clotting drugs for even a brief period can lead to the formation of a clot. There are several reasons why a patient may have to stop taking the drugs at any time. Anti-clotting drugs such as Plavix and aspirin cause excessive and dangerous bleeding during and after surgery. Patients who are taking these drugs must stop taking them a few days before an operation. If a patient become ill in a way that prevents keeping food down, such as a gastrointestinal illness or food poisoning, they risk losing the benefits of the drugs even if they attempt to keep taking them.
It was initially believed that short-term use of anti-clotting drugs immediately after placement of drug coated stents would alleviate the danger of late stent thrombosis, but the reality is that the drugs may have to be taken indefinitely, anywhere from three years to a lifetime. Long term use of anti-clotting drugs is cost-prohibitive to patients and very profitable for pharmaceutical companies.
Boston Scientific’s Taxus and Johnson & Johnson’s Cypher are the leading drug coated stents. More than a million patients receive the stents every year resulting in revenues of over $5 billion per year. Safety concerns came to light as early as 2004, but it was not until August, 2006 that Boston Scientific met with the Food and Drug Administration to discuss potential concerns. The stents are currently used for applications beyond what they were originally approved for contributing further to the risks. Even after meeting with both Boston Scientific and Johnson & Johnson the FDA is not requiring a label change.
Although the dangers of drug coated stents have proven to be far greater than originally anticipated, their use has dropped only slightly. Some patients will benefit greatly from the stents, but the benefits may not outweigh the risks. Anyone who chooses to use drug coated stents must work closely with cardiologists and any other doctors that they may see to minimize risks, and even so may encounter serious complications or sudden death.
If you or a loved one has suffered injury or death due to the use of a drug coated stent, contact an experienced defective medical device attorney today.