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Deep in the Heart
Three-D printed models of newborns’ hearts, biodegradable stents, cardiac MRI showing the heart in seven dimensions and innovative wearable cardiac devices—this new edition of MedicalExpo e-magazine goes deep inside the human heart to unveil the latest trends in cardiology
We also interviewed an expert from the U.S. Food and Drug Administration to understand how they regulate 3D printed devices, and we offer you a taste of new healthcare IT products showcased at the conhIT Conference this month in Berlin.
The Phoenix Children’s Heart Center created a couple of years ago its own in-house Cardiac 3D Print Lab. Dr. Justin Ryan, lead research scientist at the lab, and Dr. Stephen Pophal, interventional cardiologist, explained to MedicalExpo how 3D printed models of babies’ hearts represent a tremendous aid in surgical...
A medical breakthrough, bioresorbable scaffolds are designed to repair and restore diseased coronary vessels. They are intended to deliver results similar todrug-eluting stents before being completely resorbed by the body. Despite some limitations, they usher in a new era for interventional cardiology.
A couple of square millimeters is all the space oxygen-rich blood has to push its way through the lumen of a coronary artery.
Plaque lesions along the way do not exactly facilitate the journey and may lead to Coronary Artery Disease (CAD), with its typical symptoms and complications, including angina and myocardial infarction. So ever since researchers and cardiologists have learned about the pathogenesis of CAD, they have been working on materials and techniquesto open up lesions and restore blood flow and arterial function.
Following angioplasty-balloons, bare-metal stents (BMS) and drug-eluting stents (DES), the latest addition to the interventional cardiologist’s toolbox is the bioresorbable scaffold, aka bioabsorbable or biodegradable stent, such as Abbott Vascular’s Absorb, or Elixir’s DESolve.
Dissolving Several Months After Implantation
Instead of remaining permanently inside the body, these devices aim at propping up diseased vessels by providing radial strength just as long as it is really necessary, before beginning to gradually degrade several months after implantation. Developers hope this will avoid some of the long-term problems with permanent stents, particularly important for younger patients.
Dr. Petra Guhr, Manager Marketing Communication DACH, at Abbott Vascular, Germany told MedicalExpo:
Dr. Petra Guhr (Courtesy of Abbott Vascular)
The dream has always been to find a temporary solution for a temporary problem, giving blood vessels a chance to bounce back to their natural state.
“This is comparable to putting a cast on a broken leg and removing it after the bone is fully healed,” she said. Abbott Vascular has been developing the Absorb Bioresorbable Vascular Scaffold System (BVS) since the early 2000s, winning CE certification in 2010 and a positive review by the U.S. Food and Drug Administration Advisory Committee in 2016.
Absorb BVS consists of bioresorbable scaffold and coating elements, both made of polylactide acids (PLA). Suchmaterials are also used in absorbable surgical sutures and other medical applications, and are the key constituents of Elixir’s DESolve and the ancestor of all bioresorbable scaffolds, the Igaki-Tamai stent, as well. “However, one PLA is not necessarily identical to another. Only the exact composition of the PLA and the design of the scaffold determine its essential properties, such as the speed at which the scaffold dissolves.”
Furthermore, just like Abbott’s industry standard drug-eluting stent, Xience,Absorb BVS releases Everolimus to prevent restenosis, and has an enhanced delivery system to facilitate use. According to Guhr, to date about 125,000 patients have been treated with Absorb worldwide, 13,000 of them in the context of clinical studies.
The Absorb BVS passed therecent ABSORB III non-inferiority trial, using an Xience DES control group. However, although not considered statistically significant, slightly more patients in the Absorb group (7.8%) experienced target lesion failure than in the Xience group (6.1%). This raises the question of whether the new bioresorbable technology might be inferior to established stents after all.
Dr. Sharma (Courtesy of Dr. Samin K. Sharma)
Dr. Samin K. Sharma, Professor of Cardiology at the Mount Sinai Hospital, New York City, has worked in interventional cardiology since the 1980ies and has treated patients as part of the ABSORB III trial. He explained in an interview with MedicalExpo:
I think that this is just work in process. In my opinion, interventionalists have to understand this as a proof of concept – that this is a great technology, it is here to stay, and we need to make it better.
Learning More About This Technology
“I know that a lot of people are sitting on the fence and that there is a borderline enthusiasm on this issue, but I am very enthusiastic. I have used it and I think that will be good for us,” explained Sharma. His current clinical experience with bioresorbable scaffolds includes about 75 patients in the U.S. and India.
We cannot get them in complex lesions yet, because we need to learn how this technology is going to behave in complex lesions. So until we have that, I would say, that we should reserve it for the non-complex, noncalcified lesions.
Might bioresorbable scaffolds replace DES as the gold standard for treating Acute Coronary Syndrome (ACS) in the future? Sharma thinks it will be used as “a specialty item”, particularly because of some limitations, such as when treating lesions around coronary artery bifurcations or in very large vessels.
“Once we improve techniques and maybe get second generations of biodegradable stents, at the peak time my prediction is, that it could take up to 40 percent of the DES-market.”
Accelerated visualization, depicting 3D cardiac anatomy, function, and flow analysis, with cloud-based image processing, are key advances of ViosWorks, a major innovation for cardiac MRI. Although ViosWorks is not yet commercially available, GE Healthcare and the San Francisco start-up Arterys showcased it at the...
The emergence of wearable biosensors might be fantastic for tracking the cardiovascular health of individual patients, but it raises questions of reliability of the data as well as ethical issues.
Tracking the movements of patients’ hearts has become commonplace with the advent of small, wearable cardiovascular biosensors. Improvements in flexible sensors, better algorithms and improved mobile cellular technology have all meant that pocket sized or smaller machines can provide a reliable measurement of both rate and rhythm of the heartbeat.
While this is not quite as comprehensive as a 10-electrode view of the heart that hospital echocardiographs provide, portable sensors can monitor patients 24/7 at home or as they go about their daily lives, which has enormous potential advantages in terms of lowered hospital costs and reduced inconvenience to the patient.
A number of devices are now available that have been designed specifically to allow doctors immediate and remote access patients’ heart rates and rhythms.
The fitbit blaze (Courtesy of fitbit)
Intelesen’s zensor, recently cleared by the U.S. Food and Drug Administration (FDA) provides seven-day ECG and cardiac event monitoring. It can detect a variety of arrhythmias, immediately notifying the monitoring physician. Data from the zensor is transmitted to a secure server, where it can be accessed by the appropriate healthcare professionals with the goal of preventing stroke and managing atrial fibrillation and syncope.
Medtronic have developed Seeq, a Mobile Cardiac Telemetry (MCT) system that includes a sticking sensor and a wireless transmitter. Seeq is designed for cardiac patients with frequent symptoms and provides monitoring for up to 30 days. In this case, the data is transmitted to a diagnostic testing facility where trained technicians review the data and notify the monitoring physicians in case of cardiovascular events.
Zephyr Technology Corporation, now also owned by Medtronic, have a similar BioPatch. This is wireless sensor connected to disposable ECG electrodes. BioPatch continuously monitors heart rate, respiration rate, ECG and activity levels, as well as position and posture. BioPatch data can be accessed via a dedicated web portal.
Fitness Trackers Provide Heart Data
As sensors have developed, even consumer fitness trackers can provide some insight into cardiovascular health. For example, in addition to measuring physical activity, the wrist-worn fitbit blaze measures heart rate, as does the Angel Sensor, in addition to recording skin temperature.
The Seeq system
If treating doctors can reliably and ethically access their data, such devices may have an expanding role in cardiovascular medicine. There has already been an anecdotal report of a patient presenting with a seizure and by accessing his fitbit data, the doctors could determine whether he had a pre-existing heart condition or whether the arrhythmia was acute, which is crucial for determining appropriate treatment.
All these cardiovascular data points, coming from not only patients but also consumers represent a potential bonanza for medical researchers, but making sense of that data is not without considerable challenges for the very reason wearable sensors are popular with consumers: because they can decide how, when, where and under what conditions to wear them, which obviously has implications for the reliability of the data.
Dr. Kuniharu Takei, from the Department of Physics and Electronics at Osaka Prefecture University, cautioned: “As the first step to utilize the wearable sensors, I would like to recommend that users or practitioners only monitor trends in health changes and not diagnostic results. The reliability of diagnostic results is still under consideration because they strongly depend on how the device was attached to the person, as well as other factors, such as the activity, weather, etc.”
Questions of Data Privacy and Data Protection
The ethical issues with wearable sensors are essentially questions of informed consent, where patients know what their data will be used for, and questions of data privacy and data protection. As Yasser Khan, researcher in wearable medical devices atUC Berkeley said, “Anonymizing the raw data and addinga layer of encryption should be standard practice. Most research labs do that already. But patients should make sure that these privacy and security checks are in place.”
Anonymizing the raw data and adding a layer of encryption should be standard practice. Most research labs do that already.
This is not to say that researchers aren’t enthusiastic about the prospects, quite the contrary. For Dr. Takei, the next generation of wearable devices has considerable potential for diagnosis and disease prediction, providing the data can be readily accessed from the cloud, is anonymous, and is sourced from a very large, very diverse population. In his opinion, the way to achieve this is by developing flexible, low-cost, disposable sensors that can be worn comfortably, like bandages, even during sleep.
While for Yasser Khan, “Wearable devices will play a pivotal role in shifting healthcare from hospitals to homes. In-home healthcare will free up resources for providing proper care to the aging world population. The research community have already identified the types of devices needed for in-home health monitoring. Clinical studies are a good starting point for determining the promise and capability of the wearable medical devices.”
With the rise of 3D printing in the healthcare sector, there are ongoing discussions about the U.S. Food and Drug Administration’s regulation strategy concerning 3D printed devices. MedicalExpo talked with Matthew Di Prima, Head of the Additive Manufacturing Working Group at the FDA’s Center for Radiological Devices and Health.
MedicalExpo e-magazine: How does the FDA control the quality of 3D printed devices?
Matthew Di Prima: Devices constructed using 3D printing technology are subject to the same regulatory review standards as devices constructed using traditional manufacturing practices.
However, 3D printing techniques have different technical considerations than standard manufacturing. Furthermore, traditional manufacturing settings have design controls and systems, such as for complaint handling, that 3D printing settings may not have. That is why devices manufactured using 3D printing technology may need additional or different testing than what is normally performed for products that are manufactured using traditional (subtractive) techniques. As 3D printing technology develops, FDA may provide further clarity on quality control issues such as material qualifications and sterility.
Devices manufactured using 3D printing technology may need additional or different testing than what is normally performed.
Regarding 3D printing materials, materials used in formulating or constructing medical products are evaluated for safety or effectiveness within the context of overall safety and effectiveness of the medical product for its intended use. Note that FDA does not clear or approve materials for medical devices and/or products, it clears or approves finalized medical devicesand/or products.
Software used in conjunction with 3D printing is regulated through the same pathways as other medical device software. The specific pathway will depend on the intended use and risk level.
ME e-magazine: 3D printing often relates to personalized medicine. How does it impact the FDA certification process?
Matthew Di Prima: Patient-matched devices (a form of personalized medicine) or devices made from a common design and adjusted to more closely fit a patient’s anatomy or physiology, are currently regulated through FDA’s existing regulatory pathways. The device manufacturer must still show the devices meet the safety and effectiveness criteria as required by the type and class of that device.
ME e-magazine: How do you deal with medical manufacturing facility equipped with 3D printers?
FDA is considering regulatory options for individuals who would like to print medical devices at home.
Matthew Di Prima: 3D printers to fabricate medical devices are generally considered to be manufacturing equipment subject to Good Manufacturing Practice/Quality System regulations but are not considered to be medical devices themselves.
The objects that are fabricated by these printers are considered to be medical devices if they are intended for use as specified in the Act (FFDCA) or are labeled or promoted for such use.
FDA is also currently considering regulatory options for individuals who would like to print medical devices at home or other user sites and anticipates providing information in the near future.
3D Printer at the Wake Forest Institute for Regenerative Medicine (Courtesy of WFIRM)
ME e-magazine: 3D printing opens new challenges in terms of biocompatibility, sterility and cleaning. How should these challenges be handled?
Matthew Di Prima: Biocompatibility, sterility, and cleaning are concerns with all medical devices. The FDA held a workshop in October of 2014 on 3D printing in which these concerns were discussed with industry and academia.
Additionally, the FDA is conducting research to better understand how these challenges vary for different 3D printing technologies and is working to develop a draft technical guide to assist industry in addressing these concerns. The device manufacturer must show that their product has no safety or effectiveness issues regarding biocompatibility, sterility and cleaning.
Saving time always matters. In hospitals, it means saving lives. Nuance Communications, supplier of speech and imaging technologies, offers with Dragon Medical One dictation technology that may significantly reduce the time spent by physicians typing patient records.
Dragon Medical One is a securedcloud-based speech recognition platform developed for fast, easy, mobile patient documentation.
“We offer up to 22 different languages, including different accents such as Swiss or Austrian German,” explained Milko Jovanoski, International Marketing Manager for Healthcare at Nuance, in an interview with MedicalExpo. “Users can also operate the system with voice navigation. Studies show that doctors can save 30 minutes or more a day like this.” Dictionaries for different fields of medicine are provided, be it radiology, surgery or internal medicine.
Studies show that doctors can save 30 minutes or more a day like this.
Dragon Medical One turns any workstation into a “dictation station.” It can be installed on a variety of devices, including laptops, smartphones, workstations and tablets. The installation takes only a few minutes and updates are installed automatically. Voice profile training is not necessary; the technology includes accent detection and automatic microphone calibration. Vocabulary can be personalized and individual user profiles improve the quality of the records.
Integration of Nuance’s narrative capture solution into clinical work is easy. The doctor just opens the client application, places the cursor where the text should appear and dictates notes or patient history. It is transcribed in real time and transferred to the cloud and into the EHR. “Like this staff that works elsewhere or takes over after the change of shift can access the data almost simultaneously,” says Jovanoski. “Time consuming handovers become dispensable.”
The software is compatible with most leading electronic patient records systems (EHR).
Dragon Medical One enhances physician mobility and clinical workflow beyond hospital walls. It can be used in the office, at home or in the car. However, the private cloud solution currently is only available in the U.S. market.
The same product is offered in Europe as Dragon Medical 360 Direct. In the European version, access to data is only granted to users who are directly connected to the central hospital server.