A new study published in this monthÃ¢â‚¬â„¢s Journal of the American College of Cardiology (JACC) has shed light on the <"http://www.yourlawyer.com/topics/overview/drug_coated_stents">blood-clotting risks associated with drug-coated stents. According to Swiss researchers, drug-eluting stents impede the formation of whatÃ¢â‚¬â„¢s known as corollary blood vessels and therefore increase the strain on the heart muscles–making the heart less equipped to handle sudden blood clots.
Ã¢â‚¬Å“In the event of stent thrombosis,Ã¢â‚¬Â the authors write, Ã¢â‚¬Å“impaired collateral function in patients with DES could render the thrombosis more dangerous (i.e., could worsen the consequences of abrupt coronary occlusion by increasing mortality).Ã¢â‚¬Â
Not much is definitively known about the formation of corollary blood vessels, but scientists believe that the heart naturally creates these Ã¢â‚¬Å“alternate routesÃ¢â‚¬Â in order to maintain healthy blood flow to and from the heart. In their study, the Swiss research team led by Dr. Christian Seiler of University Hospital in Bern discovered that, six months after implantation, patients with drug-eluting stents (DES) have 30 to 40 percent reduced coronary collateral function when compared to patients with bare-metal stents (BMS).
According to the studyÃ¢â‚¬â„¢s authors, Ã¢â‚¬Å“Drug-eluting stents have an inhibitory effect on the production of cytokines, chemotactic proteins, and growth factors, and may therefore negatively affect coronary collateral growth.Ã¢â‚¬Â After studying a cohort of 120 patients with stable but long-term coronary artery disease, they concluded: Ã¢â‚¬Å“Collateral function long after coronary stenting is impaired with DES (sirolimus and paclitaxel) when compared with BMS. Considering the protective nature of collateral vessels, this could lead to more serious cardiac events in the presence of an abrupt coronary occlusion.Ã¢â‚¬Â
Stents are small wire-mesh devices intended to prop open clogged arteries. Drug-coated stents are implanted to prevent re-blockage of the arteries after surgery, a common problem with the bare-metal stents. However, the increased risk of thrombosis associated with DES has forced medical professionals to reassess the risks and benefits of the controversial device.