Cardiac Imaging News

Researchers from the John Hopkins University have reported that they have recently developed a predictive method that can determine, with 95 percent accuracy, which stroke victims will serve to benefit from intravenous clot-busting drugs and which ... Read more

Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have recently developed an ultrasound device that could help identify arterial plaque that is at high risk of breaking off and causing a heart ... Read more

According to a study recently published in the journal JAMA, there has been a steppe decrease since 2006 in the use of nuclear myocardial perfusion imaging (MPI; an imaging procedure used to determine areas of the heart with decreased blood flow), ... Read more

Based on research conducted at Linköping University in Sweden, one reason why malformations are not detected is obesity in the expectant mother. Moreover, six out of ten grave heart defects in fetuses go unnoticed in the ultrasound scans administered to all pregnant women. On an annual basis 2,000 children are born in Sweden with serious malformations, of which almost half are heart defects. Detecting these during the first stage of pregnancy is a significant challenge for prenatal healthcare. "The lives of children born with serious heart defects are in constant danger; some of them need immediate operations or medical treatment. If these defects are detected during the pregnancy the babies can be born in Lund or Gothenburg where the hospital has facilities for child heart surgery," explains senior physician at the Linköping University Hospital Women's Clinic and also a graduate student in obstetrics and gynaecology at Linköping University, Eric Hildebrand. The root of his study is an examination of over 21,000 ultrasound scans in the south-east healthcare region in Sweden, covering the counties of Jönköping, Kalmar, and Östergötland. In this region all expecting mothers are offered two ultrasound scans, the first in weeks 11-14, and the second in weeks 18-20. In the first scan the midwife dates the pregnancy, searches for the possibility of twins and carries out a general examination of the anatomy of the embryo. In the second scan the organs are screened for malformations. In the examination the results of the two scans are compared. Unsurprisingly, considerably fewer malformations are revelaed in the first scan. It was especially difficult to detect heart defects. During the eleventh to the fourteenth weeks no defects were found at all, yet in the eighteenth to twentieth week, 37% of serious defects were discovered. One reason for missing malformations is that the ultrasound image is affected by the body of the mother. For instance diagnosis is made more difficult by obesity-a BMI over 30-which is the case for 13% of the mothers. "Subcutaneous fat detracts from the quality of the image, making it more difficult for us to see malformations," said Hildebrand. The statistics also reveal that obesity itself raises the risk of conditions like spina bifida, although the increased risk for the individual is small. That makes it doubly important to be able to provide strong embryo diagnostics for the expectant mother. In the case of chromosome abnormalities, a thorough examination of the national medical birth register of children born between 1995 and 2010 showed that one in 700 children was born with Downs syndrome. A certain connection with obesity was also seen. Hildebrand suggests a couple of important measures for a more trustworthy embryo diagnostic that came out of the in the studies: -The methods of detecting heart defects need to be improved. One way is to give midwives additional education and training in interpreting heart images, including with what is known as color Doppler for blood flow in the heart. -The best diagnostic tool for Downs Syndrome is the CUB, or Combined Ultrasound and Biochemical screening test, which works just as well regardless of whether the mother is obese or ... Read more

According to a new study by researchers at UC San Francisco, as long as low-cost statins, which lower cholesterol, are readily available and patients don't mind taking them, it doesn't make sense to perform a heart scan to measure how much plaque ... Read more

Back when US health administrators issued an advisory in 2008 warning that computed tomography (CT) imaging might interfere with pacemakers or implantable cardioverter-defibrillators, the medical community needed more evidence to support the health agency’s recommendations/suggestions. According to a new study, researchers now have reported their findings of the first study to assess the apprehension in “real world,” medical practice. The results showed that such negative interference, if it exists, is not significant enough to warrant drastic changes in medical practice. The study’s findings were published online February 2014, in the Journal of the American College of Cardiology.  “The presence of cardiac devices should not delay or result in cancellation of clinically indicated CT imaging procedures,” stated the study’s senior author, Timm-Michael Dickfeld, MD, PhD, associate professor of medicine at the University of Maryland School of Medicine (Baltimore, MD, USA) and chief of electrophysiology at the Baltimore Veterans Affairs (VA) Medical Center. The original US Food and Drug Administration (FDA) counseling, which prompted this study, recommended having a physician present during CT scans, ready to take emergency measures to manage possible adverse events, and to observe the rhythm device in the patient following CT imaging to provide correct function. An updated FDA advisory, issued in 2013, did not pay special focus to standard device checks but called for a physician to be available when the CT involves continuous scanning over the device for more than a few seconds. “For CT scans for diagnostic purposes, the FDA advisory may warrant further evaluation,” said the study’s lead investigator, cardiovascular medicine fellow Ayman Hussein, MD. In retrospect, the researchers studied the records of patients who received over 500 CT scans between July 2000 and May 2010 performed at the University of Maryland Medical Center and the Baltimore VA Medical Center. They searched for key adverse effects such as abnormally high or low heart rate, death, an immediate intervention, hospital admission, or secondary effects such as changes in the device caused by CT imaging. However, the scans did not produce any of the primary outcomes, while several slight secondary effects were noted in a small group of devices, but there was no clear tie to CT. Similar changes were seen in a group of devices not exposed to CT. “Clinicians and the FDA are collectively committed to patient safety. We also must rely on outcome data that helps us decide on the course of action best for our patients. This study provides what is probably the best information we will have for years to come,” noted Dickfeld. “At the very least, the study may provide valuable input for reevaluation of the FDA’s original advisory,” said study co-author and associate professor of diagnostic radiology and nuclear medicine at the University of Maryland School of Medicine, Jean Jeudy Jr., ... Read more

Based on a new study published online in the journal Radiology, noninvasive imaging of carotid artery plaque with MRI can precisely predict future cardiovascular events like strokes and heart attacks in people without a history of cardiovascular disease. For quite some time researchers have known that some arterial plaque is more hazardous due to its vulnerability to rupture. MRI can distinguish features of vulnerable plaque, such as a lipid core with a thin fibrous cap. This capability makes MRI a promisingly valuable tool for identifying patients at risk for later cardiovascular events. To study the predictive value of MRI plaque imaging, researchers conducted carotid artery ultrasound and MRI on 946 asymptomatic patients from the Multi-Ethnic Study of Atherosclerosis (MESA). The carotid arteries are the large vessels found on either side of the neck that carry oxygenated blood to the front part of the brain. They are highly accessible for imaging, and their condition tends to mirror that of the coronary arteries that supply the heart with oxygenated blood. The researchers applied ultrasound to evaluate carotid wall thickness and MRI to define carotid plaque composition and the remodeling index, a measure of changes in vessel size. Imaging results were juxtaposed with cardiovascular events, including heart attacks, stroke and death, for an average of 5 and a half years following examination. "We studied asymptomatic individuals with a low risk of cardiovascular events at baseline and used noninvasive imaging to predict the risk of an event downstream. This is the first population-based prospective study to determine if vulnerable plaque features by MRI add to the risk of a cardiovascular event beyond the traditional risk factors,” said David A. Bluemke, M.D, Ph.D., from the National Institutes of Health Clinical Center in Bethesda, Md Cardiovascular events took place in 59 of the patients. Abnormal thickening of the carotid artery wall and the existence of a lipid core and calcium in the internal carotid artery on MRI were major predictors of subsequent events. A lipid core was present in almost half of the patients who had an event, as opposed to only 17.8 percent of those who did not have an event. "The primary factors that predicted future risk were measures of vessel wall thickness in combination with the presence or absence of a lipid core. The presence of a lipid core was 50 percent more common in people who had subsequent events,” said Bluemke. Use of MRI improved the reclassification of baseline cardiovascular risk in the study group. When both the carotid remodeling index and lipid core were used for risk stratification, around 16 percent more patients with events and 7 percent without events were correctly reclassified compared with the use of traditional risk factors. "The results bolster the use of MRI as a surrogate marker of efficacy in therapeutic studies and point to a role in determining which patients might need more aggressive treatments. As risk factor prediction gets better, we'll be able to screen more intelligently and use more intensive treatments in those individuals who face a higher risk of cardiovascular events,” said Bluemke. Bluemke noted that sequences for plaque composition could be readily integrated to existing carotid MRI angiography protocols for clinical purposes. "Carotid MRI has significant advantages," he said. "The results are more reproducible than those of ultrasound." Availability and cost effectiveness could limit and restrict the use of MRI, Bluemke warned. However, ultrasound and computed tomography (CT) are viable alternatives for screening, he noted, especially with improvements in CT dose ... Read more

With bird's eye imaging, cardiologists see the earliest signs of heart disease or existing heart disease not diagnosed with other testing modalities. "With one heartbeat, within one second, we can get an entire 3-D image of the heart that allows us to look at arteries and heart anatomy with excellent detail," exclaims Steven Mottl, D.O., medical director of non-invasive cardiology at The Heart Hospital Baylor Denton. The facility started to employ its 256-slice CT scanner in January; and is the first of its kind in Denton County and the third in the Dallas/Fort Worth area. Additionally, physicians can view the heart's anatomy, the pulmonary arteries and aorta and even the coronary arteries where atherosclerosis occurs. "Patients and physicians are both frustrated that we have difficulty predicting a potential heart attack. With this type of study, it allows us to characterize the type of plaque a patient may have and use this information to predict whether a heart attack could occur. This allows us to select the patients that would benefit from more aggressive medications to lower their risk of having a heart attack, and eliminate the need for unnecessary additional testing in patients that are at low risk,” explains Mottl. The 256-slice CT scanner requires only one second to scan the whole heart offering more information with each rotation, as opposed to four rotations when using a 64-slice CT scanner, or 16 rotations when using a 16-slice CT scanner. These older generation CT scanners require longer time to capture the image of the heart and require administration of medications to slow the heart rate to an accurate picture. Another clear advantage to the 256-slice scanner is that patients are not required to hold their breath during the scan. Often, many patients struggle to maintain an adequate breath hold, which leads to un-interpretable images and possible need to repeat the scan. Some patients, especially children, sometimes require the use of sedation medications for imaging on older CT scanners. While reducing heart disease with earlier diagnoses is one objective, reducing potential radiation exposure during the imaging procedure is just as if not more important. According to Mottl, medical radiation for tests such as a CT scan are the cause for up to 50 percent of an individual's life time radiation exposure, and thought to be responsible for two percent of all cancers and much higher prevalence of cataracts. The 256-slice CT scanner can provide cardiologists a picture of the human heart with 60 percent less radiation exposure than older CT scan technology on average and in some patients greater than 90 percent reduction. "With a 64-slice CT scan, the radiation exposure can be compared to having a few thousand chest X-rays. With the newer 256-slice CT technology, the radiation exposure would be equal to 100 chest X-rays," said Mottl. The new 256-slice CT scanner also offers diagnostic uses beyond diagnosing heart disease. "This scan allows us to look at vascular disease from the head to the foot. The scanner's superior resolution allows us to more accurately look for disease in vessels like the renal arteries, carotid arteries, or arteries of the legs,” adds medical director of radiology at The Heart Hospital Baylor Denton, Steven Reiman, ... Read more

A new imaging technique used for measuring blood flow in the heart and vessels can diagnose a common congenital heart abnormality, bicuspid aortic valve, and could very well lead to better prediction of any future complications. A Northwestern Medicine team reported their discoveries in the journal Circulation. In the study, the researchers exhibited, for the first time a previously unknown relationship between heart valve abnormalities, blood flow changes in the heart, and aortic disease. They revealed that blood flow changes were caused by certain kinds of abnormal aortic valves, and they were able to directly link blood flow blueprints with aortic diseases. "Blood flow in patients with bicuspid aortic valves was significantly different compared to that in patients with normal valves. We now have direct evidence that bicuspid valves induce changes in blood flow and that the type of flow abnormality may contribute to the development of different expressions of heart disease in these patients,” said senior author and associate professor of radiology at Northwestern University Feinberg School of Medicine, Michael Markl. Bicuspid aortic valve is a heart condition in which the aortic valve only has two leaflets, instead of the usual three. It affects around one to two of every 100 Americans and is the most prevalent congenital cardiovascular abnormality. Regardless of the non-existence of symptoms, the condition can lead to major and potentially life-threatening complications, including enlargement of the blood vessel (aneurysm) and rupture. However, it is not known which patients are at the highest risk for complications and whether the condition's source is genetic or associated to changes in blood flow. The 4D flow MRI (magnetic resonance imaging) employed during the course of the study has the potential for better predictive ability. "The study demonstrated that new imaging techniques may help to determine patient-specific changes in blood flow to better understand which regional areas of the aorta are most prone to developing disease," said Markl. "In addition, the knowledge of abnormal blood flow patterns could be important to better identify patients at risk for the development of heart disease." Markl's team was quite taken aback when they saw such a clear distinction between individual expressions of aortic complications for different types of congenital valve disease. While the present data demonstrates evidence of this association, long-term observational studies are required to better understand the potential of 4D flow MRI to improve disease prediction ability. A longitudinal follow-up study in patients with bicuspid aortic valves is currently being carried out at Northwestern. "Ultimately, we hope that this imaging technique will facilitate early identification of high-risk blood flow patterns associated with progressive aortic enlargement, improving the allocation of health care resources in caring for patients with this prevalent condition," Markl ... Read more

Researchers from the Georgia Institute of Technology have creating the technology for a catheter-based device that would provide insightful, real-time, three-dimensional (3D) imaging from inside the heart, coronary arteries, and peripheral blood vessels. With its all encompassing imaging, the novel device could better aid surgeons when working in the heart, and possibly allow more of patients' clogged arteries to be cleared without major surgery. The device incorporates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. On-chip processing of signals permits data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, enabling it to easily travel through circuitous blood vessels. The insightful images produced by the device would offer extensively more information than current cross-sectional ultrasound could or can. Researchers have developed and tested a model able to present image data at 60 frames per second, and plan next to perform animal studies that could result in commercialization of the device. "Our device will allow doctors to see the whole volume that is in front of them within a blood vessel. This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels,” said, professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology, F. Levent Degertekin. Findings and details of the research were published online in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Research leading to the development of the device was supported and funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health. "If you're a doctor, you want to see what is going on inside the arteries and inside the heart, but most of the devices being used for this today provide only cross-sectional images. If you have an artery that is totally blocked, for example, you need a system that tells you what's in front of you. You need to see the front, back and sidewalls altogether. That kind of information is basically not available at this time,” said Degertekin. The single chip device integrates capacitive micromachined ultrasonic transducer (CMUT) arrays with front-end CMOS electronics technology to provide 3D intravascular ultrasound (IVUS) and intracardiac echography (ICE) images. The dual-ring array includes 56 ultrasound transmit elements and 48 receive elements. When gathered, the donut-shaped array is just 1.5 millimeters in diameter, with a 430-micron center hole to house a guide wire. Power-saving circuitry in the array shuts down sensors when they are no longer required, enabling the device to function with just 20 milliwatts of power, decreasing the amount of heat generated inside the body. The ultrasound transducers operate at a frequency of 20 megahertz (MHz). Imaging devices working from within blood vessels can offer higher resolution images than devices working from outside the body because they can function at higher frequencies. However, operating inside blood vessels calls for devices that are tiny and flexible enough to travel through the circulatory system. They must also be able to operate in blood. Performing such a task requires a large number of factors to transmit and receive the ultrasound information. Transmitting data from these factors to external processing equipment could involve many cable connections, potentially limiting the device's ability to be threaded inside the body. Degertekin and his collaborators have taken not and have addressed such a challenge by miniaturizing the elements and carrying out some of the processing on the probe itself, allowing them to attain what they believe are clinically-useful images with only 13 cables. "You want the most compact and flexible catheter possible. We could not do that without integrating the electronics and the imaging array on the same chip,” Degertekin explained. Based on their mock-model, the researchers anticipate to perform animal trials to showcase the device's potential applications. They ultimately expect to license the technology to an established medical diagnostic firm to conduct the clinical trials necessary to obtain FDA approval. In the meantime, Degertekin hopes to develop a version of the device that could guide interventions in the heart under magnetic resonance imaging (MRI). Other plans include further reducing the size of the device to place it on a 400-micron diameter guide ... Read more

A recent study analysis of more than 220 US hospitals demonstrates wide variation in the use of noninvasive imaging in patients admitted to the emergency department with chest pain. Regardless of the variation, hospitals with high rates of imaging did not have lower MI readmission rates than those with lower rates of noninvasive cardiac imaging. Yet patients treated at hospitals that were frequent users of noninvasive imaging were more likely to be admitted to the hospital and to undergo coronary angiography. Our experience is that there are a lot of different approaches being employed by hospitals around the country, some with protocol-based chest-pain centers and others with more ad hoc approaches. And it seems like there is much less discretion in terms of patients who would merit imaging and how best to apply it. We wanted to get some perspective on how much variation there was and whether there was any relationship between the variation and patient outcomes,” said senior investigator from Yale University School of Medicine, New Haven, CT, Dr. Harlan Krumholz. According to Krumholz the study, recently published online February 10, 2014 in JAMA: Internal Medicine, was meant to offer some data on the nationwide assessment of patients with suspected ischemic heart disease, particularly those with acute coronary syndromes. These patients are often difficult to track because they can be lost to follow-up once they enter into the hospital. The current analysis is predicated on data from the PREMIER database of 2700 acute-care hospitals in the US. All in all, 549 078 patients from 224 hospitals were included in the study, and the use of noninvasive imaging ranged from 0.2% to 55.7%. When the hospitals were stratified by quartiles (Q), the use of noninvasive testing was performed 6.0%, 15.9%, 23.5%, and 34.8% in Q1, Q2, Q3, and Q4, respectively. Myocardial perfusion imaging and stress echocardiograms were the most frequently employed imaging tests. In total, 80.4% of the 113 602 imaging tests performed were myocardial perfusion tests, 16.6% were echocardiograms, and 1.2% were computed tomography coronary angiograms (CTCAs). "We found a remarkable variation in the use of imaging, which is an expensive intervention, and its use was strongly linked to what happened to the patient subsequently. The testing cascade has been discussed in other articles, but this is more proof that the more expensive tests you do the more likely you are to pursue additional tests,” said Krumholz. When compared with those in Q1, hospitals with the highest rates of imaging (Q4) were more likely to admit patients and conduct coronary angiography. Hospitals with lower rates of imaging performed angiography in 1.2% of patients as opposed to 4.9% in patients treated at hospitals with higher use of noninvasive imaging. The rate of coronary revascularization was also higher among patients treated at hospitals with higher rates of noninvasive imaging. Yet, in terms of revascularizations per imaging study and revascularizations per angiogram, hospitals in Q1 had significantly better yield than those in Q4. In spite of the differences in care among hospitals more likely to use imaging, there was no difference in the patients readmitted to hospital within the month or the following month. "We couldn't find any evidence that patients are being benefited by the approach," said Krumholz, referring to the higher rates of imaging at some hospitals. “A lot of hospitals don't have any feedback in terms of where they stand in relationship to other hospitals with their use of noninvasive imaging tests. In analyzing the patient characteristics and hospital factors, the group also found that nearly 25% of the between-hospital variation is attributable to institutional factors and not the types of patients treated. Regarding best clinical practices, the study was not designed to determine whether imaging was appropriate, but the researchers contend that patient-case mix would unlikely account for the variation in cardiac imaging rates,” he added. In an accompanying article, Drs Ezra Amsterdam and Edris Aman from the University of California, Davis point out that accelerated diagnostic protocols (ADPs) involve identifying low-risk patients based on clinical stability, a normal ECG, and a negative biomarker test. Predischarge testing is then used to identify patients for early discharge, and this could include anything from an exercise treadmill test to CCTA. "At the University of California, Davis, Medical Center in Sacramento, we practice physician discretion in selecting patients for predischarge testing. In more than 500 patients discharged directly from the unit after evaluation consisting of normal results of electrocardiograms and cardiac troponin tests, there has been only one adverse cardiac event (0.2%) at the 30-day follow-up,” they write. However, such tactics depends on attaining a detailed family history, an accurate assessment of the ECG, and a reliable assay for cardiac troponin, as well as the willingness of clinicians to implement such an algorithm, especially given the hazards of a missed acute coronary ... Read more

Miracor Medical Systems GmbH recently announced that it has finalized a four month follow-up of patients enrolled in its "Prepare RAMSES" clinical trial of its PICSO® (Pressure-controlled Intermittent Coronary Sinus Occlusion) System designed to improve myocardial perfusion after primary PCI (Percutaneous Coronary Intervention, or angioplasty). Provisional data from early results designate a strong pattern towards a larger reduction in infarct size at four-month follow-up for patients receiving the PICSO therapy in accompaniment with primary PCI as opposed to a historical control group. A total of 30 patients have successfully enrolled in the clinical trial, with no device-related adverse events. The study is currently underway in several European centers of excellence with Jan J. Piek, MD, PhD, professor of interventional cardiology and director of the Heart Centre within the Academic Medical Centre, University of Amsterdam, serving as Principal Investigator. "The initial clinical data show the potential of PICSO as an adjunctive therapy in the treatment of primary PCI and warrant further evaluation in larger size trials," said Piek. "These promising clinical results mark an important milestone for the development of our technology," added CEO of Miracor Medical, Ludwig Gold. "To date, 138 patients have been treated successfully with the PICSO therapy, and we could prove that PICSO® is safe and provides benefits for the patients. Therefore we are expanding the use of the CE-marked PICSO® device to additional centers throughout Europe to provide more patients the access to this new therapy and to start early commercialization." The Miracor PICSO® Impulse System is designed to treat acute heart attack STEMI patients in conjunction with coronary angioplasty. 'STEMI' is an acronym meaning ST-segment Elevation Myocardial Infarction. Heart attacks are separated into three kinds, according to their severity. A STEMI heart attack is the most severe type. In a STEMI heart attack, the coronary artery is totally blocked off by the blood clot, and as a result virtually all the heart muscle being supplied by the affected artery starts to become ... Read more