ORLANDO, Florida The frenzied pace of discovery in the cardiovascular sector was reflected at the American Heart Association's (AHA; Dallas, Texas) annual scientific sessions with a flurry of significant new data presented at the cavernous Orange County Convention Center during the November meeting.
CardioGenesis (Foothill Ranch, California) a developer of angina-relieving transmyocardial revascularization (TMR) and percutaneous myocardial revascularization (PMR) technology, reported on the complete follow-up of 212 patients who took part in its original multi-center, randomized, controlled TMR pivotal trial. The results, presented by Keith Allen, MD, of Indiana Heart Hospital (Indianapolis, Indiana), showed that patients randomized to TMR by CardioGenesis' holmium:YAG laser had a significantly improved survival rate, 65% at five years, than those randomized to maximum medical management, 52%. The overwhelming majority of patients treated with TMR (88%) continued to experience significant improvement in angina pain five years after their original TMR treatment.
Robert Emery, MD, a thoracic surgeon from Minneapolis, Minnesota, was among a group of clinicians who commented favorably on the study. "This report indicates improved survival and quality of life in 'no option' coronary patients through TMR," Emery said. "This represents a significant advance in the therapy for this form of heart disease ... a condition that is often frustrating for both the patient and physician if left untreated."
The study data was collected in nine medical centers and showed that patients treated with TMR, a procedure in which physicians use a laser to create small channels in the heart muscle, improved with statistical significance from an average Canadian Cardiovascular Society angina score of 4.0 (severe) to an average of 1.2 (mild) after five years. Additionally, 33% of TMR patients compared to 11% of medically managed patients were completely angina free after five years.
Richard Heuser, MD, of St. Joseph's Hospital and Medical Center (Phoenix, Arizona), an interventional cardiologist who began referring patients for TMR in 1999, said, "This is the first time in a large series of patients that we see, in addition to symptomatic improvement, a mortality benefit with TMR."
PLC Systems (Franklin, Massachusetts) reported that data from a research study involving TMR with its carbon dioxide (CO2) Heart Laser technology combined with autologous stem cells was presented by Race Kao, MD, professor at the James Quillen College of Medicine at East Tennessee State University (Johnson City, Tennessee). He presented data from a preclinical animal study titled "Autologous Stem Cells and Transmyocardial Laser Revascularization for Myocardial Infarction." Commenting on the study, Kao said, "We are very encouraged by the early results of this revolutionary approach to increase ventricular function and enhance revascularization. The success of this project could lead to the development of a therapeutic procedure for the millions of patients suffering from coronary heart disease and heart failure. The data demonstrates that CO2 TMR, combined with implanting autologous myogenic stem cells, significantly reduced scar areas, improved myocardial perfusion and enhanced contractile function after myocardial infarction."
Kao discussed results from CO2 TMR in combination with the implantation into heart muscle of autologous (the patient's own) myogenic (muscle-forming) cells from skeletal muscle expressing angiogenic factors. It is believed that the transplantation of autologous myogenic cells into CO2 TMR channels within the heart muscle will form new muscle tissue that will restore the contractile function and an expression of angiogenic factors will develop new blood vessels to improve perfusion of the damaged heart muscle after a heart attack. The myocardium (heart muscle) does not have myogenic cells like skeletal muscle. An injured heart typically repairs itself by scar formation and multiplication of non-muscle cells, which do not restore the damage that results from a heart attack.
In other AHA news:
Myocor (Maple Grove, Minnesota), a privately held, clinical evaluation stage medical company, reported the presentation of an abstract of its TRACE feasibility trial on the Coapsys Annuloplasty System. The abstract, titled "Off-Pump Mitral Valve Repair Using the Coapsys Device: Early Results in Patients with Functional Mitral Regurgitation," reports favorable outcomes on the ability of Myocor's Coapsys device to geometrically reshape the mitral valve and to improve valve function on a closed, beating heart without the use of cardiopulmonary bypass.
"Early results of the international feasibility study demonstrated that the Coapsys device dramatically reduced or eliminated heart valve leakage using a simple, less-invasive approach with likely lower risk than traditional mitral valve repair techniques," said lead investigator Naresh Trehan, MD, executive director of Escorts Heart Institute and Research Center (New Delhi, India).
Based on the success of its feasibility study, Myocor said it has received approval from the FDA to begin a clinical trial of the Coapsys system. The Randomized Evaluation of a Surgical Treatment for Off-Pump Repair of the Mitral Valve (RESTOR-MV) trial is the next step toward receiving U.S. marketing clearance from the FDA for the Coapsys device.
The company said the RESTOR-MV is the first North American-based, randomized clinical study evaluating mitral valve repair therapies in patients with functional mitral regurgitation. The multi-center, prospective, randomized clinical trial will evaluate the safety and effectiveness of the device in treating patients with mild, moderate or severe mitral valve regurgitation who are undergoing coronary artery bypass grafting (CABG). To date, 26 patients have been enrolled in the RESTOR-MV study, with a total of 40 patients implanted worldwide. The company expects up to 25 North American centers to participate in the study.
Camtronics Medical Systems (Hartland, Wisconsin), a subsidiary of Analogic (Peabody, Massachusetts), introduced its CIMT Screen, a measurement, analysis and reporting software package that can help identify patients with pre-clinical atherosclerosis and clarify cardiovascular risk at the meeting. CIMT Screen is part of VERICIS for Vascular Ultrasound, a new application that is tailored to the image management and reporting requirements of non-invasive vascular procedures.
Camtronics' CIMT Screen software enables the measurement and analysis of carotid intima-media thickness (CIMT), a non-invasive test that quantifies an individual's current atherosclerotic burden. Using these measurements and other risk factors, the software derives a mathematical estimate of an individual's "vascular age" (pending FDA review). In clinical practice at the University of Wisconsin Hospital and Clinics (UWHC; Madison, Wisconsin), substituting vascular age for chronological age has been shown to improve the applicability of population-based coronary heart disease risk estimates, the company said.
James Stein, MD, the lead clinical developer of CIMT Screen and an associate director of preventive cardiology at the University of Wisconsin Medical School (also Madison), presented an abstract regarding CIMT measurements and metabolic syndrome at the AHA gathering.
Cholesterol in the skin can provide a useful index of hidden cardiovascular disease, according to a new study. Levels of skin cholesterol measured non-invasively by Cholesterol 1,2,3, developed by IMI International Medical Innovations (Toronto, Ontario), correlated with the presence of coronary calcification, which is thought to be predictive of cardiovascular events. "We found that non-invasive skin cholesterol testing was associated with the presence of coronary artery calcification, independent of serum lipid measures, and may provide a useful marker of subclinical, or hidden, atherosclerosis," said Brent Norton, IMI president and chief executive officer. "Given this information, skin cholesterol appears to be an effective tool in identifying the presence of early disease."
The data come from a cohort of the Multi-Ethnic Study on Atherosclerosis (MESA), sponsored by the National Heart, Lung and Blood Institute (Bethesda, Maryland) and conducted at Johns Hopkins Bayview Medical Center (Baltimore, Maryland). Pamela Ouyang, MD, associate professor of medicine at Johns Hopkins University (also Baltimore), is the principal investigator of the skin cholesterol study.
In the skin cholesterol study cohort, 222 adults with no known cardiovascular disease underwent skin cholesterol testing in addition to electron beam computed tomography (CT scan) for coronary calcium and serum testing to measure total cholesterol, HDL, LDL and triglycerides. Skin cholesterol levels significantly correlated with the presence and severity of coronary artery calcification, independent of serum lipids and lipoproteins in white subjects. The data showed that a one-standard deviation approximately 10 points on the skin cholesterol scale was associated with a 178% increase in the odds of having calcium in the coronary artery.
Skin cholesterol is measured by the Cholesterol 1,2,3 test, a three-minute, non-invasive test that does not require fasting. Two drops of liquid are placed on the patient's palm and react with cholesterol molecules in the skin to generate a color-change reaction. The color is read by a spectrophotometer to provide a numeric result.
Patients who are found to be resistant to the antiplatelet effects of aspirin, as determined by the Accumetrics (San Diego, California) Ultegra Aspirin Test, were found to have more than three times the risk of elevated levels of cardiac enzymes during coronary stenting, according to a study presented by researchers from the University of Hong Kong. Elevated enzymes are associated with myonecrosis, or damage to the heart muscle, and have been shown to correlate with adverse outcomes, including increased risk of cardiac death after coronary angioplasty.
Aspirin remains a cornerstone for the prevention of heart attack, stroke and other serious cardiovascular risks, with more than 23 million Americans taking aspirin to prevent cardiovascular disease and stroke. However, as many as 30% of aspirin users may be resistant to aspirin's antiplatelet effects, and thus its protective benefits. This study adds to a growing body of research linking aspirin resistance to increased risk of cardiovascular events and highlights the value of testing patients for aspirin resistance.
Researchers used the Accumetrics Aspirin Test, a point-of-care test that measures platelet function, to determine aspirin responsiveness in 136 patients scheduled for coronary stent procedure, and found that nearly 20% of these patients were aspirin-resistant and that these patients had an increased risk of adverse outcomes in spite of being pre-treated with both aspirin and Plavix. Aspirin and Plavix are typically administered prior to the procedure to lessen complications associated with the coronary stenting procedure.
"Aspirin, along with Plavix, is the current standard of care for preventing serious complications associated with coronary stenting," said Wai-Hong Chen, MD, of the division of cardiology at the University of Hong Kong and lead investigator for this study. "The data showing elevated risks associated with aspirin resistance underscore how critical it is for physicians to determine if their patients are resistant to aspirin, in order to select the appropriate antiplatelet therapy."
Recently cleared by the FDA, the Accumetrics Aspirin test is the first rapid diagnostic test that can inexpensively test a patient's response or resistance to aspirin. The system consists of a disposable assay device and bedside instrument that measures the degree to which a patient's platelets aggregate. The results indicate to the physician whether or not aspirin is effectively inhibiting platelet function. These results help physicians make better-informed treatment decisions quickly and cost-effectively. Accumetrics specializes in diagnostic tests for cardiovascular and neurovascular disease.