May 18, 2015 — Patients with a high-risk paclitaxel drug-eluting stent given the shorter-acting antiplatelet drug cilostazol prior to a surgical procedure safely transitioned off of dual antiplatelet therapy (DAPT) to reduce bleeding risk during their operation. These new findings from the OUTSIDE START study were presented as a late-breaking clinical trial at the Society for Cardiovascular Angiography and Interventions (SCAI) 2015 Scientific Sessions in San Diego.
DAPT, including aspirin plus an antiplatelet drug, is prescribed to patients for at least one year after receiving a drug-eluting stent to prevent blood clots from forming in the stent. About 5 to 10 percent of patients have a surgical procedure during the one-year period, requiring stopping DAPT to reduce the risk of bleeding complications. However, stopping DAPT places patients at high risk of having an adverse event, such as a blood clot, heart attack or death. Further, antiplatelet drugs often must be stopped five to seven days or more before an operation for antiplatelet activity to return to normal, which extends the amount of time patients are off of DAPT and increases the risk for an adverse cardiac event.
"Patients on DAPT can be a challenge to manage during surgery because there are significant risks of a stent clotting if DAPT is stopped, while there are also significant risks of bleeding if it is not stopped," said Charles Laham, M.D., FSCAI, interventional cardiologist at HFM Heart & Vascular Center in Manitowoc, Wisconsin, and the study’s principal investigator. "To manage these 'double jeopardy' risks, we evaluated bridge therapy, which allows the patient to transition off of DAPT for their surgical procedure using a short-acting antiplatelet drug."
For the study, patients stopped DAPT eight days prior to their operation. Seven days before their operation they began receiving the drug cilostazol (100 mg) twice per day or alternatively 50 mg if they were undergoing high-bleeding-risk surgery or were intolerant of the full dose. Lower-risk patients stopped cilostazol 24-30 hours prior to their surgical procedure and resumed DAPT 12-24 hours after surgery. Patients at higher risk of bleeding during surgery stopped cilostazol 54-60 hours before surgery and resumed DAPT 24-36 hours after surgery. Researchers considered patients "fully bridged" if they received at least 600 mg of cilostazol prior to surgery and resumed DAPT by at least 48 hours after surgery.
In total, 108 patients who had a drug-eluting stent (paclitaxel) had 183 operations with a cilostazol bridge from 2005 to 2012. Researchers measured rates of adverse events during bridging and within 30 days after surgery. In total, 171 patients who were fully bridged experienced no adverse events. Twelve patients in the study did not receive the full cilostazol bridge/DAPT resumption protocol, and of those, four (33 percent) experienced an adverse cardiac event.
"Even in high-risk patients, we found cilostazol bridging is effective without the risk of adverse events or bleeding within 30 days of an operation, provided the protocol timeline was followed," said Laham.
Researchers noted the current study involved only patients who had received higher thrombotic risk drug-eluting stents coated with the drug paclitaxel, but did not include patients with the newest generation of stents. Despite having similar successes with bridging of smaller numbers of other stent types in the main OUTSIDE patient study, larger studies should be conducted to confirm whether the bridge strategy is effective for larger numbers of patients with other types of drug-eluting and bare metal stents, as they are outside the scope of the current study.
Laham reported no relevant disclosures.
For more information: www.scai.org