By Mary Carter
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(CNN) -- It may be America's No. 1 killer, but people aren't scared enough of heart disease, says a top U.S. research cardiologist.
"We've done a good job of advertising to people that we're doing better with heart disease, so people tend to sort of feel good about it," said Dr. Robert Califf, vice chancellor for clinical research at Duke University Medical Center. "We have bypass surgery and stents and drugs that work; the [mortality] rates are declining."
It's true that U.S. heart disease deaths overall are down. From 1993 to 2003, cardiovascular disease death rates dropped 22.1 percent.
But more than 910,000 Americans still die of heart disease annually, according to the American Heart Association. And more than 70 million Americans live every day with some form of heart disease, which can include high blood pressure, cardiovascular disease, stroke, angina (chest pain), heart attack and congenital heart defects.
"It's sort of accepted as part of the background noise, even though it's far and away the mostly likely reason that you or I will die,'' Califf said.
And it will get more likely, he said. "We're just on the front end of the baby boomer epidemic, where the projections on the amount of cardiovascular disease are climbing steadily over the next 10 years," he said.
"We're delaying the disease, but we're not preventing it," said Dr. Steven Nissen, president of the American College of Cardiology and chairman of cardiovascular medicine at the Cleveland Clinic in Ohio.
Prevention is key, the experts agree, and Americans know what to do: Eat a healthy diet, keep their weight in check, exercise and don't smoke. But instead, obesity and diabetes rates continue to rise. Roughly two-thirds of Americans are overweight or obese, according to the National Center for Health Statistics. And the epidemic is spreading to teenagers and children. (Explainer: Your heart 101)
"We can't expect significant change until it becomes a cultural mandate," said Dr. Leslie Cho, director of the Cleveland Clinic's Women's Cardiovascular Center. "When society as a whole makes conscious decisions to eat better and as a default plan be more active, then we're going to do better."
But could that happen anytime soon?
"I don't know," she said. "If you had asked me if New York City was going to be smokeless, I would have said no a couple of years ago." The city's proposed ban on transfat in restaurant food is another potential advance, she said.
Looking for the new drug
In the meantime, Nissen and other heart experts see cause for optimism in new drugs and surgical techniques that help improve quality of life and could one day reverse the effects of heart disease. (Gallery: Heart help on the horizon)
Nissen is leading clinical trials of a drug that appears significantly to raise HDL, or high-density lipoprotein. HDL is known as the "good cholesterol" because it collects deposits from artery walls and sweeps them back to the liver.
The introduction nearly 20 years ago of statins, drugs that can cut LDL, the low-density lipoprotein or "bad" cholesterol that carries cholesterol through the body, revolutionized treatment of heart disease.
"We're about to do it again with HDL," said Nissen, who is optimistic about the future of HDL-raising drug treatment.
By combining the new drugs with the old statin standbys, "we're going to be able to get a lot of people's HDL higher than their LDLs. That's going to make a difference," Nissen said.
Torcetrapib, the focus of Nissen's trials, is more effective than previously tested HDL-raising drugs, he said, and in pill form, it's more practical than its predecessor, which had to be injected. Its notable side effect so far has been a possible one- or two-point rise in a patient's blood pressure.
But the drug has not been without controversy. Its maker, Pfizer Inc., originally planned to market torcetrapib for use only in combination with the company's top statin, Lipitor. Doctors and others complained that the proposed combo pill would require patients taking other statins to switch to Lipitor. Last summer Pfizer withdrew that plan and agreed to sell torcetrapib alone.
Nissen expects to get final data from the study next year. Last month, though, Pfizer appeared to be lowering expectations, telling analysts that its pursuit of Food and Drug Administration marketing approval was really the beginning of a broader conversation about the drug's overall value. The company said it would not be surprised if more data were required before the FDA OKs the drug.
Another drug being closely watched that may be approved for U.S. sale in 2007 is rimonabant, which blocks receptors in the brain that can help reduce the risk of heart disease and type 2 diabetes.
The drug made by Sanofi-Aventis has been found to cause weight loss and, more specifically, loss of abdominal fat. Fat around the middle is linked to an increased risk for heart disease. Available in Europe under the brand name Acomplia, rimonabant works both in the central nervous system, blocking a brain receptor that triggers cravings -- the so-called "munchy receptor" -- and peripherally, in fat cells.
Duke's Califf noted that depression has been reported as a significant side effect in testing of rimonabant. He said he believes more research is warranted.
"The battlefield of medicine is littered with drugs that ought to work but don't," he said.
Seeking stem cell discoveries
The quest for new treatments continues in many directions. The use of stem cells, both promising and controversial, has not had the hoped-for success in improving heart function.
In September, three studies in the New England Journal of Medicine showed only small improvements in patients' cardiac function after they received stem cells from their own bone marrow.
But Dr. Robert Simari, a researcher at the Mayo Clinic in Rochester, Minnesota, found some unanticipated results that are being studied further. The research, he said, showed that stem cells seemed to have a protective effect against more heart attacks, death or the need for a subsequent stent or bypass surgery.
"I'm thinking these trials are telling us something about cell delivery that we might not have imagined," Simari said. "That the effect might be more global and protective than one might have considered."
Rather than suggesting that bone marrow cells could repair a heart by becoming heart cells, the Mayo team is using cells already destined to become endothelial cells, which make up the lining of blood vessels, to try to repair the vessels themselves.
"We think of if it almost as a cellular bandage at a site of injury," he said.
Simari said he thinks the delivery of cells could help fight the problem of post-treatment clotting. Emerging data shows an increased risk of potentially deadly clots in patients who have received drug-eluting stents to help keep their arteries open. The drug-coated stents, considered revolutionary in heart disease treatment in the last two years, appear to do better than their bare-metal predecessors at keeping the arteries open.
But in an October guest editorial in the online journal of the American College of Cardiology, two doctors asserted that the widespread use of the devices has led to more than 2,000 extra deaths a year from clots. They called for a rethinking of the stents' use. The FDA plans to hold hearings in December to seek more information on the issue.
Simari said one remedy could be to create a nonclotting surface on the stents. He said he believes the best way to do that is to get the normal healing process started as quickly as possible. "We can do that very quickly by applying cells," he said.
But when it comes to heart disease, preventive measures are still the best, according to experts.
"Even though there are medications that are coming out, still the hardest thing to do is the best thing for you," said the Cleveland Clinic's Cho. "I think the problem is that everybody in America kind of knows what to eat. But it's just a matter of portion control and a matter of changing your lifestyle so that you do pick good things."
In the meantime, doctors and researchers will continue to seek ways to improve patients' quality of life.
"Lifestyle and prevention are always the better strategy, and I believe that and I work at that," Nissen said. "But when you can't prevent the disease, we're going have better tools to treat it."