Findings from the BRIDGE study reveal that cangrelor, an investigational intravenous antiplatelet, achieves very fast blood thinning effects when needed to protect from heart attacks and also dissipates rapidly so patients can undergo surgery without the excessive bleeding often associated with blood thinning medications. The study was led by physicians at Scripps Health, California, USA.
The BRIDGE trial tested the efficacy of cangrelor, an antiplatelet that allows patients to be “bridged” from the time that their physicians stop their oral antiplatelet drugs until they undergo cardiac surgery. Study results demonstrated cangrelor maintained target levels of platelet inhibition known to be associated with a low risk of blood clotting events, such as stent thrombosis. Initial results from the BRIDGE trial have been published on 18 January 2012 in the Journal of the American Medical Association (JAMA).
“This represents an important practical step forward in cardiovascular care,” said leading author and primary investigator of the study, Eric Topol, chief academic officer at Scripps Health and director of the Scripps Translational Science Institute (STSI). “For the first time we have validated a way to prevent clotting in patients who have had a recent stent but still require medication as they bridge to another surgery. This represents a fairly common clinical situation—the unplanned operation in a patient with a recent stent.”
The BRIDGE trial was a double-blind, randomised study conducted in 210 patients in the United States and Europe. The trial took place between January 2009 and April 2011. Results showed 99% of cangrelor-treated patients maintained target levels of platelet inhibition for all time points measured over the bridging period compared to 19% of placebo patients with no significant excess in surgical bleeding complications.
Patients who have had heart attacks or who have been treated with stents are commonly treated with blood thinning medications to help prevent future cardiovascular events. The most commonly used blood thinning medications for these patients are aspirin and clopidogrel (also known as Plavix).
“Many of these patients may require surgery at some point in time making how best to manage their blood thinning medications challenging,” said Matthew Price, Scripps interventional cardiologist and co-author. “In fact, if they do not stop their blood thinning medication prior to surgery they have a high risk of bleeding, but if they do stop their blood thinning medications they have a high risk of developing a heart attack, which is often fatal.”
Attention was brought to this issue in 2004 when former US president Bill Clinton presented with a mild heart attack that required urgent bypass surgery. He had received aspirin and Plavix, and as a result, had to wait six days before the surgery was performed. According to Topol, these considerations underscore the importance of identifying strategies patients to be safely bridged to their surgical procedure with minimal risk of developing heart attacks or bleeding complications.
According to 2009 data from the Organisation for Economic Co-operation and Development (OECD), more than 2.5 million stent procedures are performed globally per year. Treatment guidelines in the United States and Europe recommend stent patients receive blood thinning medications for up to 12 months following their stent procedure. It is estimated that up to 25% of these patients with stents in place will require a surgical procedure during the first five years after.