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Rare Use of Drug Derived From Leech Saliva Lets Heart Transplant - And Wedding - Proceed
Los Angeles - Aug. 21, 2007 - Los Angeles resident Daryl Vinson, 39, desperately needed a heart transplant but was allergic to heparin, a blood thinner that plays a critical role in transplantation surgery.
Rather than allowing their patient to languish and die, members of the heart transplant team at Cedars-Sinai Medical Center created an alternative, using a synthetic form of a protein found in the saliva of leeches. Bivalirudin was recently approved by the Food and Drug Administration for the treatment of certain cardiac conditions, but because it has no antidote and its use in transplantation is so new, the doctors had to develop a game plan and specific protocols in advance of the operation.
Vinson, a former Air Force air traffic controller who also served with the Global Command and Control System, caught what he thought was a common cold that quickly got worse in early June. After suffering a nearly fatal collapse, he was diagnosed with idiopathic dilated cardiomyopathy, a severely weakened, poorly functioning heart.
While dilated cardiomyopathy can be caused by a number of factors, including reduced blood flow to the heart ("ischemic" disease), Vinson's condition likely stemmed from a viral infection.
"Mr. Vinson appeared to be in relatively good health, so it was a surprise to everyone, including his physicians, that his heart function was so bad," says Ernst Schwarz, M.D., Ph.D., a specialist in transplantation cardiology.
"The doctors basically told me I was dying," recalls Vinson, who had returned to Los Angeles in January from his hometown of Memphis to direct communications for the Compton school district. During a year back home helping his mother and disabled stepfather, Vinson had fallen in love and become a father.
"I had to call my fiancée in Memphis and tell her I probably couldn't get married in October; that I was dying," Vinson said.
He was transferred to Cedars-Sinai on June 29, and the initial plan was to implant a cardiac defibrillator, says Schwarz. That effort was thwarted by the discovery of a massive blood clot in the patient's left ventricle, the heart's main pumping chamber. 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.
"Here's a guy who was playing football not long ago, who was very successful and looking forward to marriage and family," says Sinan Simsir, MD, surgical director of Cedars-Sinai's Heart Transplant Program. "The next week, he has the heart function of someone near death."
Lawrence Czer, MD, medical director of Cedars-Sinai's Heart Transplant Program, and director of Transplantation Cardiology, concurs: "Mr. Vinson had such an advanced case of heart failure that he was put on the organ wait list almost immediately."
With Vinson's heart working at just 10 percent capacity, his doctors were close to giving him an artificial heart pump to keep him alive, but 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 Simsir, so the team would have to use an alternative.
"Heparin is critical in transplantation because it prevents blood clots from forming while the patient is on the heart-lung machine," explains Czer, who says the situation intensified when it was verified Vinson had heparin-induced thrombocytopenia (HIT) syndrome, which prohibited use of any heparin-related blood thinner. This condition affects an estimated one to four percent of patients treated with heparin.
Fortunately, Simsir had previous experience using bivalirudin. Marketed as Angiomax, the heparin alternative is now indicated for use in coronary interventions, including angiograms and stent procedures, and for the treatment of angina, heart attack, deep vein thrombosis and other blood clots.
There was a problem, though. Typically, a blood thinner such as heparin is followed by a course of protamine to restore the blood's normal coagulation after surgery.
"There is no antidote for bivalirudin," says Czer, explaining the increased risk. "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."
Prior to surgery, the transplant team developed new protocols for use of the agent, which took 24 hours to collect in the large quantities required. Bivalirudin presented two distinct challenges, according to Simsir: 1) the lack of an antidote and, 2) no proven track record. He adds that many transplant centers would have refused the case. "Who knows how many patients with HIT are turned down?"
Schwarz believes this encounter with bivalirudin will open the door to more transplant procedures for heparin-sensitive patients. "The agent's use is relatively new in the OR, so this has been a valuable experience for us."
The transplant was completed in a three-hour procedure without complications, thanks largely to bivalirudin, the synthetic form of hirudin, a powerful anticoagulant produced by the salivary glands of medicinal leeches. Vinson went home three weeks later.
"I have a new birthday, you know. It's July 25, 2007 – the day I got my new heart," he says.
The "rest of the story" - After surgery, an in-hospital marriage ceremony
Just before surgery, Vinson presented a proposal and ring to his fiancée, Margo McLemore, who had dropped everything in Memphis to rush to his side in Los Angeles.
"I didn't get down on my knees, though, because I wasn't sure I'd be able to get back up," he adds with a laugh.
Also at Vinson's side throughout his ordeal was the man he calls "Pops," Don Ross, a prominent former newsman – one of the first African-Americans in the business – who is now involved in the entertainment industry.
Vinson remembers regaining consciousness after surgery: "I looked around and thought, I don't see angels, I don't hear singing – cool!"
That relief was followed by a flood of emotion and overwhelming gratitude for the gift of his life, Vinson says.
"I was thanking God and crying. I'd never experienced such love, compassion, competence and care. I wondered, what did I do to deserve this? I have a joy that I can't even explain."
Vinson's exhilaration inspired him to "tie the knot" right away, he says. The couple and their witnesses gathered Aug. 10 in Cedars-Sinai's chapel for a small, simple Judeo-Christian ceremony.
Though Vinson faces several months of recuperation and weekly medical checks, his prognosis is encouraging – two biopsies have shown no sign of organ rejection. He looks forward to returning home with his new wife and young son, Joshua, and to resuming the job he'd already learned to love in Compton.
Aside from the physicians and staff who saved his life, Vinson feels indebtedness – and a sense of responsibility – to his anonymous donor.
"I have double to do now, because another life was given to me. Someone died so that I could live, and I need to be worthy of that sacrifice."