MacroPore Biosurgery (San Diego, California) has received a fast-track Phase I/II Small Business Innovation Research (SBIR) grant from the National Institutes of Health (NIH; Bethesda, Maryland) to study the role of adipose-derived regenerative cells in treating myocardial infarction. This research will be conducted in collaboration with W. Robb MacLellan, MD, at the David Geffen School of Medicine at the University of California, Los Angeles.

MacroPore and its collaborators have shown that adipose tissue is a rich source of autologous regenerative cells, which contain adult stem cells, and the SBIR studies will evaluate the capacity of adipose-derived regenerative cells to improve revascularization and regenerate damaged myocardial tissue following a heart attack. By using adipose tissue as a cell source, MacroPore intends to demonstrate that it can obtain therapeutically relevant quantities of regenerative-capable cells in real-time.

"The limited ability of the adult heart to regenerate itself after an injury such as heart attack frequently leads to heart failure or other complications," said MacLellan. "The research performed to date at MacroPore suggests that regenerative cells purified from adipose tissue may represent a clinically useful source of cells to promote myocardial regeneration in patients immediately after a heart attack." Christopher Calhoun, president and chief executive officer of MacroPore, said his company "has gained a significant understanding of the potential clinical applications for adipose-derived regenerative cells from our preclinical studies."

TRI³SVR results positive for CHF

Marisa Di Donato, MD, professor of cardiology at the University of Florence (Florence, Italy) and director of cardiovascular research at San Donato Hospital (Milan, Italy), reported results on congestive heart failure (CHF) patients who received TR³ISVR (pronounced tri-saver) surgery, during the Society of Thoracic Surgeons' 40th annual meeting in San Antonio, Texas, in late January. The study, including 175 patients, showed an 89% survival rate in those who have been followed over a 19-month period.

The TR³ISVR procedure, developed by Chase Medical (Richardson, Texas), is a surgical alternative to treat heart failure, using Chase's Mannequin device to resize and reshape the damaged heart close to its original form, thus helping the weak heart to pump more efficiently.

"We have observed a marked improvement resulting from the restoration of a better left ventricular geometry," said Di Donato. "In these patients, mitral regurgitation decreased significantly and functional status improved. These results are impressive for patients with post myocardial infarction, cardiomyopathy, and who are at high risk of death." Di Donato is a lead investigator for the TR³ISVR Multi-Center Clinical Registry, which documents clinical outcomes relative to patients undergoing surgical ventricular restoration (SVR) with use of the Tr³ISVR Mannequin. Her data showed that the TR³ISVR procedure helped to significantly improve the overall pumping function of the damaged heart; improve the level of heart failure classification; and improve the heart valve function.

Chase Medical also recently received FDA 510(k) clearance for its new diagnostic software product, SIMON, which is used to provide imaging details and data concerning the left ventricle of the heart. The software is designed to aid in selecting patients for the TR³ISVR procedure, provide accuracy in performing it and measure the status of congestive heart therapy. Chase said that it is expecting commercial rollout of SIMON in March.

More CT needed for plaque measurement

Marck Kahn, MD, says that pressure is mounting on health insurance companies to provide more coverage for computed tomography scans that accurately measure the buildup of calcified plaque in the major arteries of the heart. Kahn, medical director of EBT-Heart & Body Imaging (Detroit) and Michigan Heart Imaging (Flint, Michigan), made his comments following the release of a new study validating the use of electron beam tomography (EBT) coronary artery screening to assess heart attack risk in intermediate risk patients. "Now we have another major study supporting its use as a diagnostic tool for intermediate-risk heart patients," Kahn said. "The EBT heart scan is simply the best detective we've ever put on the mystery of hidden heart disease."

Kahn said the study, published recently in the Journal of the American Medical Association, provides compelling evidence for the use of high-speed EBT scans in patients who are considered at moderate risk of a heart attack. He said that determining the level of treatment for this "middle risk" group, using traditional risk factors such as blood pressure, cholesterol, smoking and family history, has been frustrating for both patient and physician, but the EBT scan can now remove some of that guesswork, and doctors can make better and more aggressive treatment decisions.

"A heart attack or sudden cardiac death is not the way to find out you've got heart disease," said Kahn. "Unfortunately, that's the first sign of trouble for more than half of all Americans with heart disease." The EBT heart scan used at Kahn's imaging centers in Detroit and Flint measures a person's calcium score based on the quantity of heart vessel calcium deposits. The greater the amount of calcium deposits, the higher the score.

diaDexus test shows Lp-PLA2 as key risk

A prospective case study of the Atherosclerosis Risk in Communities (ARIC) population, published Feb. 2 in the online edition of Circulation, the journal of the American Heart Association (Dallas, Texas), supports the measurement of lipoprotein-associated phospholipase A2 (Lp-PLA2) to help identify individuals at risk for coronary heart disease (CHD). The research team, led by researchers at Baylor College of Medicine and Methodist DeBakey Heart Center, examined the relationship between Lp-PLA2, C-reactive protein (CRP), traditional risk factors and the risk for a CHD event over the course of six to eight years, stratified by low-density lipoprotein (LDL) cholesterol. The study was funded by a research grant from the National Heart, Blood, and Lung Institute (Bethesda, Maryland) and diaDexus (South San Francisco, California).

Lp-PLA2 levels in the ARIC population were measured using the PLAC test, developed by diaDexus, and cleared by the FDA to aid in the prediction of an individual's risk for a CHD event, in conjunction with clinical evaluation and patient risk assessment. Scientists at GlaxoSmithKline (GSK; London) discovered Lp-PLA2 and have postulated that it plays a role in atherosclerosis by causing an inflammatory process, resulting in the build-up of plaque on the arterial walls. GSK has exclusively licensed certain intellectual property relating to Lp-PLA2 and the PLAC test to diaDexus for clinical diagnostics. Lp-PLA2 is an enzyme, usually bound to LDL cholesterol in the blood, and has been found to be present in plaque. The scientists hypothesized that the enzymatic action of Lp-PLA2 yielded inflammatory mediators leading to CHD.

The results of the study show mean levels of Lp-PLA2 and CRP were higher in the 608 men and women who developed CHD events than a matched group of 740 individuals who remained free of CHD. The study also determined that for individuals with LDL cholesterol below the median (130 mg/dL), both Lp-PLA2 and CRP were significantly and independently associated with CHD in fully adjusted models. Individuals with normal LDL levels (<130 mg/dL) but elevated Lp-PLA2 levels were shown to be at twice the risk for a coronary event compared to individuals with low levels of Lp-PLA2. Moreover, individuals with normal LDL levels, but elevated levels of both Lp-PLA2 and CRP, had three times the risk for a cardiac event.