VCU Health System launches surgical study of blood-thinning drug

By Joe Kuttenkuler

RICHMOND, Va. – A blood-thinning drug already approved for use during coronary balloon angioplasty procedures in the catheterization lab is now being put to the test in the operating room. Surgeons at the Virginia Commonwealth University Health System recently performed one of the first quadruple heart bypass procedures in the country using Angiomax, an anti-coagulant that could eventually replace heparin – the most commonly used blood-thinner.

Since the study began in November 2002, four patients have received Angiomax during surgery � all have done well.

"Blood has two competing systems – clotting and non-clotting – and these systems are in a very delicate balance," said Abe Deanda, M.D., assistant professor of cardiothoracic surgery in VCU's School of Medicine. "We must manipulate that balance during cardiac surgery to prevent blood from clotting during critical stages of a procedure."

The anti-coagulation drug study will compare Angiomax (bivalirudin) to heparin. Researchers will evaluate the side effects and blood behavior of both during and following surgery. Angiomax is a thrombin inhibitor that temporarily turns off the protein thrombin that causes blood to clot.

Unlike heparin, which is longer acting and requires a second drug to reverse its blood-thinning effects, Angiomax is short acting and clears the body more quickly without any additional medication. Heparin is given as an injection � Angiomax is administered as a constant infusion.

"The primary reason we end up giving patients blood following heart surgery is due to bleeding that occurs as we try to reverse the effects of blood thinning medication," Deanda said. "A shorter acting blood thinner may potentially reduce or eliminate the need to give blood."

Blood thinners must be used during heart bypass surgery when the heart is stopped and a pump is used to circulate blood through the body. According to Deanda, as blood passes through the plastic tubing that runs to and from the heart pump it tends to clot – sensing the foreign environment as an injury.

European trials using the drug under surgical conditions have produced positive results. Deanda hopes to enroll 10 patients in this initial study. Patients will be followed for a year after surgery.

"Angiomax may well decrease a number of serious, adverse events in the operating room that previously have been accepted risks with cardiac surgery," said Bruce Spiess, M.D., a VCU Health System anesthesiologist and the primary investigator of the drug in the U.S.

The most common side effects associated with Angiomax are back pain, nausea, headache and hypotension.

The Food and Drug Administration approved Angiomax in Dec. 2000 for use on patients with unstable angina during cardiac balloon angioplasty procedures. Angina is a condition that produces moderate to severe chest pain caused by a temporary reduction of blood flow to the heart muscle.

The drug's manufacturer, The Medicines Company, is funding the study.

The VCU Health System is the only medical center in the state conducting the anti-coagulation drug study.