News article 1/24/05
This patient taking heart
An experimental therapy shows promise for people like Jerry Crone, who have exhausted all treatment options for severe coronary artery disease.
BY TOM MAJESKI
Pioneer Press
Jerry Crone of Cannon Falls, Minn., could be called the Cardiac Kid.
Since June 1990, Crone has experienced six heart attacks, 11 angiograms, a double coronary bypass and the installation of nine stents, including one in a clogged bypass graft. He also has a pacemaker and a defibrillator.
"They're going to put a zipper in there pretty soon," he quipped.
But thanks to an experimental procedure performed on him five years ago, Crone, 59, dances — "I love to go out and boogie," he says — rides horses and motorcycles and walks three or four miles at a time without developing any chest pains.
"I haven't had any angina for a long time," Crone said. "I even cut down on my medications."
The procedure was done on 45 patients in the Twin Cities and several other centers around the country. It represents a viable option for the growing number of Americans who have run out of treatment options for their severe coronary artery disease, said Dr. Tim Henry, who has spearheaded the local study as director of research at the Minneapolis Heart Institute Foundation. Henry and his counterparts across the country are now looking for additional patients for the second phase of the study — another step toward Food and Drug Administration approval, which is likely years away.
Severe cardiovascular disease is the second leading cause of death in the United States. It killed more than 450,000 Americans in 2002, the latest year for which data is available. According to the American Heart Association, 54 percent of those deaths were attributed to coronary artery disease.
Because people are living longer, "there is an increasing number of patients who have blockages you can't fix with bypasses or angioplasty," Henry said.
Crone, a single father with two sons, was in that group. "There was nothing we could do with more surgery or angioplasty," Henry said. "He had terrible pain and couldn't get a job or do anything."
During the procedure, which was performed at Abbott Northwestern Hospital, Henry opened Crone's chest and injected a growth hormone called Vascular Endothelial Growth Factor-2 directly into his heart muscle. The drug was developed by Atlanta-based Corautus Genetics.
"We used a little needle and injected it in six different locations," Henry said.
Once in the heart muscle, the growth hormone genes work their way into individual cells, prompting them to produce a protein that, in turn, promotes the growth of new blood vessels. These vessels grow around coronary artery blockages and increase the supply of oxygen-enriched blood flowing to the heart muscle.
Henry said the technique enhances the natural process of collateral vessel development that often occurs in patients whose coronary artery blockages build up slowly over time. "All we try to do is enhance the natural process," he said.
Dr. Jay Cohn, a nationally known cardiologist and head of the University of Minnesota's Rasmussen Center for Cardiovascular Disease Prevention, said the technique makes sense but that it will take a long time and a lot of study before it can be proven that it works in patients.
"But it certainly is an idea worth pursuing," Cohn said. "It may work like gangbusters in some patients and not in others. But that's the nature of the business. We have to keep ourselves skeptical but encouraged. I'm very supportive of what he's doing."
Results from the first round of testing are very promising, Henry said.
"Eighty percent of the patients treated with (the growth factor) experienced a decrease in their angina by two or more levels, and 40 percent of the patients experienced a complete elimination of angina symptoms altogether," he said.
Under the second phase of the study, Henry and his colleagues at 24 other cardiac medical centers around the nation will enroll nearly 500 patients to compare the growth hormone treatment with a placebo. Participants will be followed for a year to see how well they do.
To be eligible, participants must have Class III or Class IV angina.
"These are people who can't walk to the mailbox because of chest pain," Henry said.
Between 40 and 50 of the participants will be from the Twin Cities area.
"I just got started right before Christmas. I've done seven patients so far and it's gone really well," Henry said.
Participants in three groups will receive the hormone while those in a fourth group will get a placebo. No one will know which participants received the hormone until the study is complete, Henry said.
But unlike Crone, who had to have his chest opened and his heart exposed, participants in the latest study will be injected internally, Henry said.
The new technique involves inserting a special catheter into the participant's femoral artery, threading it though the aortic valve and into the heart. Then a tiny needle on the tip of the catheter injects the growth factor into the heart muscle at six different locations.
"It's far less invasive," Henry said. "Patients can go home the same day."
Crone says he feels much better since he underwent the procedure.
"The most I ever walked is 4½ miles, and this was at a fast pace," he said. "I got bucked off horses three times last summer. I'm not a person to lay down and die."
FYI
For more information about the Endothelial Growth Factor-2 study, call the Minneapolis Heart Institute Foundation at 612-863-3976. |
