WEDNESDAY, April 23 (HealthDay News) -- A multinational team of researchers has succeeded in turning human embryonic stem cells into three types of human heart muscle cells.

When transplanted, the cells also improved heart function in mice.

The findings have a number of implications, the most immediate of which would be to use the cells to test drugs.

"We have now a supply of human heart cells for biotech and drug companies to start testing the beneficial effects of drugs or the toxic effects of drugs," said Gordon Keller, senior author of a paper published in this week's issue of Nature. "There are really no roadblocks in beginning to set up such tests."

Researchers may also be able to use the cells to make artificial heart tissue, which could then be transplanted into an actual human heart.

"It's not clear how effective injecting cells directly into the heart ever will be," said Keller, who is director of the McEwen Centre for Regenerative Medicine at University Health Network in Toronto. "A huge advantage we have is that these unique progenitor cells can make three of the major types of cells in the heart, so we hope we can simply seed these progenitor cells onto scaffolding and make what might be an artificial piece of heart tissue and possibly transplanting such small pieces of tissue, and engrafting them into the heart, would be more effective than transplanting the cells themselves."

Keller's lab had previously succeeded in coaxing cardiac cells out of mouse embryonic cells.

For this study, the team used similar principles, applying specific growth factors at different stages of development, but in human embryonic stem cells.

"They're showing that different 'recipes' can induce different types of cardiac cells," said Paul Sanberg, director of the Center for Aging and Brain Repair at the University of South Florida College of Medicine in Tampa.

In this way, the researchers were able to isolate heart progenitor cells then coax them into three different types of heart cells, called cardiomyocytes, which make up functioning heart muscle.

"Now we have our hands on a cell that doesn't have the same developmental potential as embryonic stem cells but can still make three of the major types of heart cells," Keller explained. "When we have these cells in isolation, we have a better handle on directing their pathway to cells that beat, or other [cardiac] cells. That's much more difficult when we haven't isolated the cells."

Also, when these cells were transplanted, they didn't form tumors, which often happens when a group of cells is more mixed. "In essence, we have isolated the most immature human heart cells, and we think we can control these cells much better than we would if we were starting with embryonic stem cells," Keller said.

The findings will help researchers better understand how the heart develops in humans, but therapeutic applications are still a ways off.

"It's important that we understand the basic biology," Sanberg said. "But it's still going to be a while till we see this in the clinic."

More information

The National Institutes of Health has more on stem cells.

TUESDAY, April 22 (HealthDay News) -- Hospitals that perform fewer cardiac bypass operations don't have more deaths following the procedure than hospitals that handle a greater number of bypasses, a new study says.

This finding contradicts conventional wisdom, which has assumed that hospitals that do more cardiac bypass operations have better results, with fewer patient deaths.

"Volume isn't the key ingredient or the driving force behind outcomes," said lead researcher Dr. Rocco Ricciardi, of the Lahey Clinic and Tufts University School of Medicine, in Massachusetts.

"We found over a long period of time that outcomes improved across the country no matter where you seek care," Ricciardi added. "It's been a gradual reduction in the number of coronary artery bypass graft cases performed because of the growth of less invasive techniques," such as angioplasty.

The study findings are published in the April issue of the Archives of Surgery.

In patients with coronary disease, the arteries that supply blood and oxygen to the heart become hardened and narrowed. If lifestyle modifications and medicines don't help, a doctor may recommend coronary artery bypass surgery (CABG). Surgeons take a piece of a vein from the leg or artery from the chest or wrist, and attach it to the coronary artery above and below the narrowed area or blockage. This allows blood to bypass the blockage, according to the U.S. National Library of Medicine.

For the study, Ricciardi and his colleagues collected data on 108,087,386 people admitted to U.S. hospitals from 1988 to 2003. Among these patients, 1,082,218 underwent cardiac bypass surgery.

Over the course of the 16-year study period, the rate of cardiac bypass surgeries increased from 7.2 cases per 1,000 patients in 1988 to 12.2 cases per 1,000 patients in 1997, before dropping back to 9.1 per 1,000 patients by 2003. During that same time span, the number of angioplasties tripled.

And from 1997 to 2003, the number of hospitals doing large numbers of cardiac bypass surgery dropped from 32.5 percent to 15.5 percent. Despite this shift, however, the death rate after cardiac bypass surgery dropped from 5.4 percent in 1988 to 3.3 percent in 2003, the researchers found.

What's more, the largest decrease in death rates was among the hospitals that performed the fewest cardiac bypass operations.

Ricciardi's team believes its findings show that using death rates after cardiac bypass surgery may no longer be an accurate gauge of the quality of care provided by a hospital.

"Measuring quality is obviously difficult," Ricciardi said. "Trying to determine which hospital will give you the best outcome, and where you get the best quality medicine, is very difficult to determine based solely on surgical volume."

Dr. Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles, said he agrees with the findings. And they mirror the conclusions of other studies, he added.

"This new study adds to other recent studies which suggest that volume of cardiovascular procedures is, in and of itself, not a useful indicator of quality of care or patient outcomes," he said.

"The very good news from this study is that in-hospital mortality rates for CABG are improving at U.S. hospitals, irrespective of CABG volume," Fonarow said.

Fonarow said the volume of procedures should not continue to be used as a measure of quality care.

"The practice of health-care payers and accrediting organizations in using volume of procedures such as CABG surgery as quality criteria for hospitals should be replaced with more accurate and direct measures of quality of care and patient-centered clinical outcomes," he said.

Another expert, Dr. Samin Sharma, director of interventional cardiology at Mount Sinai Medical Center in New York City, said the death rate from cardiac bypass surgery has dropped because the procedure has become standardized and surgeons feel comfortable performing it.

"Volume used to play a major role, but now it turns out to be that volume may not be that important," Sharma said. "More important are protocols and systems that you put in place that really make a change in the outcome in mortality. People have put protocols in place that improve outcomes, whether it's a low-volume center or a high-volume center."

More information

For more on cardiac bypass surgery, visit the U.S. National Library of Medicine.

MONDAY, April 21 (HealthDay News) -- A compact heart assist device designed to fit women and smaller men has been approved by the U.S. Food and Drug Administration.

Heart assist devices are implanted mechanical devices that help weakened hearts pump blood while heart failure patients await a heart transplant. Previous models were too large to fit the upper abdomen of women and men of smaller stature, the FDA said.

The HeartMate II Left Ventricular Assist System is just 3 inches in length and weighs about 1 pound. A cable that powers the device passes through the patient's skin to an external controller, allowing the device to be powered either by battery or while connected to an electrical outlet.

In clinical testing on 126 people, 57 percent survived to undergo a heart transplant, which the FDA said is comparable to larger heart assist devices.

The manufacturer, Pleasanton, Calif.-based Thoratec Corp., will be required to conduct a post-approval study of the device's performance, the agency said.

More information

The FDA has more about ventricular assist devices.

THURSDAY, April 17 (HealthDay News) -- A cholesterol test that requires no more than a small sample of skin cells scraped off the palm of the hand can measure the risk of heart disease in healthy people, researchers report.

The test looks at levels of skin sterol, a molecular relative of blood cholesterol.

In a test on 9,055 people, skin sterol readings correlated closely with levels of good HDL cholesterol and of C-reactive protein, a marker of inflammation that is a risk factor for cardiovascular disease. Dr. Dennis L. Sprecher was expected to report on the findings Thursday at the American Heart Association Conference on Arteriosclerosis, Thrombosis and Vascular Biology in Atlanta.

The test described at the meeting is a new version of an existing skin sterol test now being used in Europe and in Canada and on a limited basis in the United States, said Michael Evelegh, executive vice president of clinical and regulatory affairs with PreMD Inc., a Canadian company that markets the older test and is developing the newer one.

"What happens with this test is that a little plastic device is applied to the surface of the palm of the hand to peel off a layer of dead skin cells," Evelegh said. "The sample is sent to a laboratory, which measures the cholesterol in those cells. It turns out that cholesterol in the skin is associated with the risk of cardiovascular disease."

In 2005, Dr. James H. Stein, of the University of Wisconsin, reported a study in which cholesterol readings of the older test correlated with ultrasound measurements of thickening and narrowing of arterial walls.

Stein said through a university spokesman that he was not free to comment on the test, because he is providing information to the U.S. Food and Drug Administration on its possible wider use.

Similar ultrasound measurements have not been done with the newer test, Evelegh said. "We have just started to generate clinical data," he said.

The older test provided on-the-spot cholesterol readings, while the new one requires samples to be sent to a laboratory for analysis.

"A test like this is useful in a setting where you want to test cholesterol without taking a blood sample, as when people are applying for life insurance," Evelegh said. The participants in the study were being screened for life insurance coverage.

A skin cholesterol test can work because, "what matters is not how much cholesterol is in the blood but how much cholesterol accumulates in the walls of blood vessels," Evelegh said. "When cholesterol accumulates in blood vessel walls, it accumulates in tissues in general, and, in particular, in the skin," he explained.

One advantage of the skin test is that "you don't have to fast," Evelegh said. "It makes no difference what you ate this morning. That has no effect on the test results." Conventional cholesterol tests do require prior fasting.

Sprecher began working on skin cholesterol testing when he was with the Cleveland Clinic. He continued the work after moving to the University of Pennsylvania. He now is with the GlaxoSmithKline.

More information

Standard cholesterol testing is described by the Mayo Clinic  .