The world’s first virtual heart has been developed to improve teaching of peri-operative transesophageal echocardiography (TEE) skills in the care of patients with heart disease. HeartWorks, a uniquely realistic computer-generated model of the heart and echocardiography simulator, is the result of a 4 year project driven by a team of three London-based cardiac anesthesiologists. Recognizing the power of education through simulation and its increasingly widespread adoption throughout clinical practice, the team is spearheading a pathway change in education in one of the most interesting and challenging areas of cardiac care. Now in production by Inventive Medical, a subsidiary of UCLH Charity London, HeartWorks is set to dramatically transform TEE training by university teaching hospitals worldwide.

Defining the challenge of teaching TEE

The role of TEE in the management of life-threatening hemodynamic instability is well established. However, proficiency in performing a TEE examination requires significant training and expertise.

As the founder and clinical leader of TEE courses at UCLH, Dr. Sue Wright, MBBS, FRCA was acutely aware that the opportunities to practice and observe peri-operative TEE were limited. With practice hours diminishing within the typical curriculum, it was becoming increasingly necessary to find a new solution to teach this advanced technique. Dr, Wright, Dr. Bruce Martin, MBBS, FRCA and Dr. Andrew Smith, MBBS, FRCA, fellow UCLH anesthetists with a keen interest in TEE, were frustrated by the lack of anatomical accuracy in current heart simulators.

Dr. Wright explained, “Together, we resolved to design a virtual heart that would break boundaries in terms of realism and student engagement. The three of us set out to develop the most anatomically lifelike heart simulator in the world to enable medical students and cardiothoracic specialists to understand both the structure of the heart and the way in which echocardiography images are derived from it.”

Designing a technology solution

With the input of clinical expertise from Sue, Andrew, Bruce and a considerable number of eminent medical specialists, media company Glassworks rose to the design challenge. The company developed an ultrasound software solution that resulted in freely interactive TEE image simulation with true-to-life control of the probe depth, and flexion and rotation of the imaging plane. Further collaboration with Asylum, a leading models and effects company, resulted in the development of a haptic interface that allows a mannequin TEE simulator to drive the HeartWorks software.

Dr. Wright continued, “At the core of the HeartWorks product is a freely interactive model of the human heart which has an unprecedented degree of detail and photorealism. The model has been carefully animated to simulate normal human cardiac motion, with a variable heart rate that is synchronized to an EKG trace. It can be viewed from any angle both internally and externally, through a range of zoom, can be rotated freely around any axis, and sliced in any plane.”

“The addition of an ultrasound simulation package introduces the facility for real time TEE image simulation from the 3D virtual heart. The on-screen introduction of a virtual TEE probe down the path of the esophagus generates simulated ultrasound images that are derived directly and continuously from the 3D model. The mannequin package supplements the ultrasound simulation package and allows the operator to perform a true-to-life TEE examination. The use of this complete simulator package allows the novice Sonographer to gain valuable early experience before examining patients.”

Dr. Nick Fletcher, Consultant in Cardiothoracic Anesthesia and Intensive Care and Honorary Senior Lecturer at St Georges Hospital and Medical School, London runs TEE courses that are attended by cardiothoracic and intensive care specialists from all around the world. Having just purchased the HeartWorks suite, Dr. Fletcher is enthusiastic about the integration of the virtual training in his curriculum. “There is enormous demand for this type of skill in the field of intensive care, from cardiac physiology students to clinical practitioners. The inclusion of the HeartWorks simulation experience in our course will enable delegates to observe and safely practice skills for a day in a typical scenario before they go on to hone their skills in the peri-operative setting. I anticipate that it will be an extremely valuable addition and we are looking forward to its imminent implementation.”

Dr. Feroze Mahmood, Director of Vascular Anesthesia from Beth Israel Deaconess Medical Centre, Boston, which is part of the Harvard Medical School, agreed, “Up until the introduction of HeartWorks, even for residents and fellows there has been no such facility or equipment to learn basic TEE skills and probe manipulations or develop appreciation of ‘normal’ outside the OR to decrease the initial TEE learning curve. Using HeartWorks in trans-esophageal echo mode, the heart appears as an actual dynamic image as observed on a real TEE machine. This powerful learning tool has greatly simplified the understanding of TEE anatomy and image orientation and has the potential to literally change the landscape of TEE training. It is a revolutionary advancement in the field of echocardiography with an enormous potential."

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Article written by staff at earthtimes.org and adapted for the purposes of this newsletter.

 

The battle for healthcare reform has begun in earnest now, with U.S. President Barack Obama stumping for far-reaching change to an audience of physicians fearful of pay cuts, healthcare insurers wary of government competition, and skeptical consumers whose views often reflect their own access to care.

If past is prologue, coronary CT angiography (CTA) faces a tough battle for coverage in an era when "comparative cost-effectiveness" -- and how it is defined -- will dominate critical coverage decisions that will increasingly take place on a national stage rather than locally.

According to a cardiologist who makes a living from coronary CTA, both performing and advocating it, CTA's powerful opponents have not only waged an unfair battle in the media, they've been less than candid about disclosing their interests. In the closing talk at last month's International Symposium on Multidetector-Row CT in San Francisco, interventional cardiologist Dr. Tony DeFrance warned that political effectiveness will be as important as cost-effectiveness in gaining broad coverage for coronary CTA in the U.S.

From the clinical standpoint, early studies show that coronary CTA can triage chest pain patients and send them home more safely and cheaply than the current standard of care, for example. But study conclusions notwithstanding, the outcome of the battle for coronary CTA could well depend on who succeeds in defining the battlefield, DeFrance said.

"A lot of it comes down to coronary CTA as a kind of poster child" for the struggle over technology adoption policy -- that and physician revenue streams, said DeFrance, who is an associate professor of medicine at Stanford University in Stanford, CA, and chief of cardiac imaging at the Nevada Imaging Center in Las Vegas.

Two realities

"Cardiac CT is a very powerful tool. It's safe and noninvasive, and we're getting more and more evidence of its effectiveness," DeFrance said. "So why is there all this resistance to adoption?"

The scientific reality is that coronary CTA isn't a perfect tool, but it's an extremely good one. Its niche in patient care is being rapidly defined as a robust exam with a negative predictive value of around 99% for ruling out coronary artery disease, he said. On the other hand, more cost-effectiveness data and more trials comparing effectiveness with the standard of care are needed.

Media menace

"The media reality is that there's been widespread criticism, and we've had negative editorials in the journals," DeFrance said. "And maybe it's just coincidence, but there seems to be a fairly coordinated press campaign in that these negative press releases come out just at critical times -- like before the (2007) Medicare decision, etc."

The mountain of negative press has included newspaper and journal articles citing outdated and excessively high radiation doses, theoretical cancer risks described as a matter of fact, and authors who have suggested that coronary CTA scans delivering "scant evidence of effectiveness" are being conducted in a single-minded bid to keep scanners busy and physicians paid.

A 2008 New York Times story noted that more than 1,000 hospitals and private cardiology practices had bought or leased the $1 million CT scanners used for CTA and other imaging procedures.

"Once they have made that investment, doctors and hospitals have every incentive to use the machines as often as feasible," authors Alex Berenson and Reed Abelson wrote (New York Times, June 28, 2008).

Characterizing CTA as a "tool of dubious value," the authors noted that under U.S. Food and Drug Administration rules CT manufacturers "do not have to conduct studies to prove that their products benefit patients." Rather, "a faith in innovation, often driven by financial incentives, encourages American doctors and hospitals to adopt new technologies even without proof that they work better than older techniques," the team wrote.

Cardiologists using the scans are simply practicing medicine the way the health system rewards them to, Georgetown University economist Jean Mitchell told the Times. Given the opportunity to recommend a test for which they will make money, doctors will use it. "This is not greed," Mitchell said. "This is normal economic behavior."

In a November 27, 2008, New England Journal of Medicine editorial discussing the results of the CORE 64 CTA trial, cardiovascular imaging specialist and health policy advisor Dr. Rita Redberg from the University of California, San Francisco (UCSF), and colleagues dismissed the evidence in favor of coronary CTA scans (NEJM, November 27, 2008, Vol. 359:22, pp. 2324-2336).

"There is no data. Cardiac CT is just a bunch of pretty pictures," Redberg and UCSF professor of medicine Dr. Judith Walsh wrote in a widely criticized editorial, entitled "Pay Now, Benefits May Follow" (NEJM, November 27, 2008, Vol. 359:22, pp. 2309-2311).
DeFrance said the authors' "fairly negative article barely even touched on the topic of study design or the factors" behind the results. "Mainly it was a kind of a pedestal to talk about certain Medicare decisions."

Among the modality's more vociferous opponents, Redberg receives funding from healthcare giant Blue Cross Blue Shield, which has opposed the adoption of coronary CTA, DeFrance said. And while there's nothing wrong with opposing the technology, those who do so need to disclose their potential biases, he said.

Third-party payers are worried about the cost of CTA, DeFrance said. "Will this cause layers of testing, and will this add to the cost of care? Some of this is valid criticism -- we do need more data," DeFrance said.

Early studies have shown significant savings with the use of coronary CTA versus the standard of care, including stress testing, cardiac enzyme tests, invasive coronary angiography, and inpatient observation.

Get scanned here now

A wave of entrepreneurial physicians pushing coronary artery calcium scans in the early days hasn't helped the political situation, DeFrance said. High radiation doses, now being reduced substantially with new techniques, have also slowed acceptance, he said.
Physicians who stand to lose money are an obvious source of opposition to CTA, he said.
"I am a cardiologist, but there is a heavy vested interest against this succeeding because of people's revenue streams," DeFrance said. "It's no secret that cardiologists make the majority of their money from nuclear [medicine scans] or at least a good percentage of it -- and from invasive catheter angiography. So some people don't want the status quo to change."

Cost-effectiveness and technology assessment

But the major struggle under way is the fight over what criteria will be used to determine the future of technology adoption policy in the U.S., DeFrance said.

"The reality of the times is that healthcare costs are at 17% of gross domestic product representing trillions of dollars in spending, double-digit growth in imaging costs over the last few years, and control of technology adoption is seen as essential to controlling healthcare costs," DeFrance said. "You see this in the headlines almost daily now, and you see these terms again and again: cost-effectiveness and comparative effectiveness."

With hard choices being made regarding the best use of scarce healthcare dollars, CTA is certain to be a flashpoint for these competing interests. Advocates of CTA see new barriers to technology adoption as a way to keep the inefficient status quo from changing.

Stakeholders in the coronary CTA debate include cardiologists, radiologists, medical societies, and vendors. At this point patients don't really play a role, DeFrance said. Some stakeholders favor the development of comparative-effectiveness data, while others are pushing for long-term outcomes data requiring lengthy and expensive trials.

Other major players are entities such as the Baltimore-based Center for Medical Technology Policy, which receive most of their funding from third-party payors. These organizations want to position themselves as an additional layer between technology development and clinical adoption. But they've been less than up-front about their funding, their plans, and the extent of their influence on government decisions -- disclosure that is essential for fostering honest debate, DeFrance said.

At this point, it's unclear who will emerge on top, be it Medicare, third-party payer-funded companies, a proposed national institute of clinical effectiveness, and/or the National Institutes of Health, he said.

But it is a high-stakes game, he said, unfolding in an era of sharply constrained budgets, massive deficits, and the new administration's determination to pass major healthcare reform legislation by October. But the core issue is technology adoption policy, which will "remain on the front burner," DeFrance said.

"We've come to the conclusion that it's not really about cardiac CT scans, the specificity, the sensitivity, the negative predictive value," DeFrance said. "A lot of it comes down to coronary CTA as a kind of poster child" for the struggle over technology adoption policy -- that and physician revenue streams, he said.

DeFrance said he's not against technology adoption policy, but "we need defined standards, and we need to know what hurdles we're jumping over."

"There can't be a changing bar, and we need to make sure new technology is helping patients," he said. "Who is going to pay for the burden of proof? The insurance companies don't want to pay for these multimillion-dollar outcome trials."

CTA wins one

Questions about outside influences on Medicare became a factor in a 2007 proposal by the Centers for Medicare and Medicaid Services to stop CTA funding under local coverage decisions and limit the test to approved trials. Medicare was charged with using a Blue Cross Blue Shield Technology Assessment critical of CTA as the basis for its proposal, which was abandoned in the wake of stiff opposition from providers, patients, and other "grassroots" CTA advocates, DeFrance said.

"It was because of the public outcry that we got almost 80 signatures from Congress, and the Senate that went to [CMS] in a flood," he said. "The reason we fought so hard is because this would have really shifted the power away from physician societies controlling [CTA] to potentially biased groups making these decisions."

The bottom line is that "technology adoption is under massive scrutiny," DeFrance said. I think this is a warning sign for future imaging modalities -- if you look at what happened to virtual colonoscopy, it's a warning sign."

Last month CMS denied coverage for virtual colonoscopy screening, citing a lack of sufficient data. The importance of technology assessment was not lost on advocates of the decision.

A May 27 editorial lauding the CT colonography (CTC) denial, authored by UCSF's Redberg and colleagues, referenced the 2007-2008 skirmish over coronary CTA when it welcomed the CTC denial as "a departure from some of its past decisions" (NEJM, May 27, 2009).

"When the CMS reopened its consideration of cardiac CT and issued a narrower draft decision memo, it received a flood of letters [from CTC advocates] in protest," the editorial stated. "In the face of these letters and considerable congressional pressure, and thanks to an internal decision that withdrawing coverage required evidence of harm or lack of benefit, the CMS withdrew the more restrictive draft national decision and issued a final decision that maintained generous local coverage. Given this history, we worry that the CMS may waver in the face of the struggle between science and politics."

Hearts and minds

DeFrance called radiation dose, limited reimbursement, and the negative media campaign the principal reasons coronary CTA implementation has lagged. In the battle for CTA coverage, political effectiveness will be as important as cost-effectiveness, he said.
Getting coronary CTA approved for the indications it handles best will require stakeholders to remain keenly informed about the issues, including comparative- and cost-effectiveness criteria as well as sound study design.

"Keep the for-profit insurers out -- or at least have them disclose their interests," DeFrance said. "And make technology adoption thresholds reflect safety concerns, common sense, and how significant a disease it is. Cardiac disease being the No. 1 killer, this is an important subject, and then get involved in a society that advocates it" -- for example the Washington, DC-based Society for Cardiac Computed Tomography (SCCT), he said.

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Article written by staff at ivfnewsdirect.com and adapted for the purposes of this newsletter.

 

Duke University engineers have taken a first step toward a minimally invasive treatment of brain tumors by combining chemotherapy with heat administered from the end of a 3-D catheter.

The bioengineers designed and built an ultrasound catheter that can fit into large blood vessels of the brain and perform two essential functions: provide real-time moving 3-D images and generate localized temperature increases.

The researchers envision using this system in conjunction with chemotherapy drugs encased in heat-sensitive microbubbles called liposomes.

"Physicians would inject drug-carrying liposomes into a patient's bloodstream, and then insert a catheter via a blood vessel to the site of the brain tumor," said Carl Herickhoff, fourth-year graduate student at Duke's Pratt School of Engineering and first author of a paper appearing in the journal Ultrasonic Imaging.

"The catheter would use ultrasound to first image the tumor, and then direct a higher-power beam to generate heat at the site, melting the liposome shells and releasing the chemotherapy directly to the tumor.

"The temperature increase would be about four degrees Celsius - enough to melt the liposome, but not enough to damage surrounding tissue," Herickhoff said. "No one has tried this approach before in the brain."

The American Cancer Society estimates that more than 21,000 new brain tumor cases were diagnosed in 2008, with more than 13,000 patients dying. This represents about 2 percent of all cancer deaths.

The researchers said that a minimally invasive approach to treating this cancer would be preferable to the conventional methods, which have drawbacks and side effects of their own.

"Surgery is invasive, and chemotherapy that is injected or taken orally affects the whole body and has difficulty crossing the blood-brain barrier in sufficient concentrations," Herickhoff said. The blood-brain barrier restricts the passage into the brain of any foreign matter not needed by the neural tissue."

In a series of experiments in animal models and simulated tissues, the researchers demonstrated that they could build a catheter thin enough to be placed in one of the brain's main blood vessels that was capable of serving the dual purpose of visualization and heating.

"Taken as a whole, the results of these experiments, in particular the clarity of the images and ability to increase temperature with the same catheter, lead us to believe that the ultimate creation of a practical intracranial ultrasound catheter is possible," said Stephen Smith, director of the Duke University Ultrasound Transducer Group and senior member of the research team. "There are some design issues of the catheter itself that we feel can be overcome with little difficulty."

Advances in ultrasound technology have made these latest experiments possible, the researchers said, by generating detailed, 3-D moving images in real-time. The Duke laboratory has a long track record of modifying traditional 2-D ultrasound - like that used to image babies in utero - into the more advanced 3-D scans. After inventing the technique in 1991, the team also has shown its utility in developing specialized catheters and endoscopes for real-time imaging of tissues throughout the body.

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Article written by staff at dotmed.com and adapted for the purposes of this newsletter.