Middle-age and older people who feel healthy, but who have early signs of atherosclerosis, are more likely to exhibit subtle changes in heart function, detectable through a special MRI technique, which may signal the beginning of heart failure, according to a new study in the June 20, 2006, issue of the Journal of the American College of Cardiology.
"The novelty of this study is that we were taught that the way atherosclerosis causes myocardial dysfunction is by causing heart attacks or chest pain or other clinical manifestations of disease. Here we have evidence that subclinical atherosclerosis, atherosclerosis that has not manifested clinically, is influencing left ventricular function, regional myocardial function, before any clinical outcome is detected. This is a paradigm shift in the way we understand how myocardial dysfunction is produced. And that speaks to the importance of the report," said João A. C. Lima, M.D., F.A.C.C. from Johns Hopkins University in Baltimore, Maryland.
Researchers at six field centers*, including first author Verônica R. S. Fernandes, M.D., studied 500 consecutive MRI studies of participants (209 women and 291 men) in the Multi-Ethnic Study of Atherosclerosis (MESA). The MESA trial is a prospective population-based observational cohort study of men and women from four different ethnic groups (Caucasian, African-American, Hispanic, and Chinese), ages 45 to 85 years old, who were free of clinical cardiovascular disease at enrollment.
Using a relatively new and extremely sensitive technique known as MRI tagging, the researchers were able to detect subtle changes in the movement of the walls of the left ventricles, the main pumping chambers, of the hearts of participants. They compared the results of the MRI heart wall motion studies with ultrasound measurements of the carotid arteries of the participants. Specifically, the researchers measured the intima-media thickness of the carotid artery. Increased thickness is known to be an early sign of atherosclerosis.
Even though the participants did not have any symptoms of cardiovascular disease, increased intima-media thickness was related to reduced heart pumping function.
"Previous studies have looked at the relationship of atherosclerosis and heart failure. We are showing, in a population of people who have never had symptoms, an association between atherosclerosis and fine changes in the heart contraction," Dr. Lima said. "These results, which were quite unexpected actually, suggest that we should perhaps implement preventive strategies more vigorously and earlier than we thought."
Possible interventions could include treatment to lower cholesterol levels or using ultrasound to watch for progression of atherosclerosis.
Dr. Lima pointed out that this study could show only that signs of atherosclerosis and reduced heart function tend to go together. Further study will be needed to see if the results can predict the future health of the participants.
"That's what we are doing now. We are following this population to see if this really relates to people developing heart failure," Dr. Lima said.
This study was not designed to explain the observed association, but the researchers say other work suggests some leading possibilities. Early atherosclerosis in major blood vessels could be producing blood flow problems and thus causing heart muscle damage, even though the participants don't feel symptoms. Blood vessel problems could be interfering with blood flow in the tiny vessels in the heart muscle.
It is also possible that the early atherosclerosis and heart function abnormalities are both connected to some underlying issue that was not identified in this study.
Tasneem Z. Naqvi, M.D., from the UCLA School of Medicine in Los Angeles, California, who was not connected with this study, said that a "strength of the study is the strong methodology, using recent and more robust techniques for the evaluation of heart function."
"The study findings might explain the etiology of heart failure in several patients who are otherwise labeled as having idiopathic cardiomyopathy. Decreased coronary flow reserve in the face of increased demand such as occurs during exercise or mental stress may lead to reduced heart function during stress and then eventually at rest. It would be interesting to find out whether exercise or mental stress challenge may bring out this abnormality even earlier. The findings suggest that screening by imaging, rather than by blood tests, is the way to detect presence of subclinical atherosclerosis as well as its effect on heart function," Dr. Naqvi said.
Amy Murphy | EurekAlert!
GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University
Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center
At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.
Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
25.04.2018 | Physics and Astronomy
25.04.2018 | Physics and Astronomy
25.04.2018 | Information Technology