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Leech Saliva Allows Heart Transplant to Proceed

Heart Transplant Team Uses Bivalirudin for Patient Allergic to Heparin

Cedars-Sinai patient Daryl Vinson, 39, desperately needed a heart transplant but was allergic to heparin. As a result, members of the medical center's heart transplant team took an unusual alternative -- using bivalirudin, a synthetic form of a protein found in the saliva of leeches that acts as a powerful anticoagulant.

Daryl Vinson and his wife, Margo (center), are pictured here with members of his heart transplant team, including (l-r) Sinan Simsir, M.D., Ernst Schwarz, M.D., Jenna Craven, R.N., Linda Piponniau, R.N., and Lawrence Czer, M.D.

Bivalirudin was recently approved by the FDA for the treatment of certain cardiac conditions. Because it has no antidote and its use in transplantation is so new, physicians had to develop a game plan and specific protocols in advance.

Vinson was diagnosed with idiopathic dilated cardiomyopathy, a severely weakened, poorly functioning heart. While dilated cardiomyopathy can be caused by a number of factors, his condition likely stemmed from a viral infection.

Vinson was transferred to Cedars-Sinai on June 29, and the initial plan was to implant a cardiac defibrillator, says Ernst Schwarz, M.D., a specialist in transplantation cardiology. That effort was thwarted by the discovery of a massive blood clot in the patient's left ventricle. A heart biopsy revealed an unusual amount of scar tissue for a patient with such a short history of non-ischemic cardiomyopathy, suggesting limited potential for recovery. A new heart was Vinson's only real hope.

A heart became available within three-and-a-half weeks, a remarkably short wait. But in his earlier course of treatment, Vinson was found to have an allergic reaction to heparin. Re-exposure during surgery could result in life-threatening clotting complications, says Sinan Simsir, M.D., surgical director of the Heart Transplant Program.

Fortunately, Dr. Simsir had previous experience using bivalirudin, which is the synthetic form of hirudin, an anticoagulant produced by the salivary glands of medicinal leeches. Marketed as Angiomax, the heparin alternative is now indicated for use in coronary interventions and for the treatment of angina, heart attack, deep vein thrombosis and other blood clots.

There was a problem, though.

"There is no antidote for bivalirudin," says Lawrence Czer, M.D., medical director of the Heart Transplant Program and director of Transplantation Cardiology. "It has to be administered very carefully, and then you have to filter it out of the system while you are transfusing blood products to reduce the bleeding. We built this filtering into our protocol."

"I have a new birthday, you know. It's July 25, 2007 -- the day I got my new heart," he says (pictured here with his wife, Margo, whom he wed after the transplant).