Dr. Nick West
Physicians: The future of cardiac imaging is now
April 09, 2021
By Dr. Nick West
As millions of Americans living with heart conditions know only too well, the important task of pumping hundreds of gallons of blood around the body each day can be derailed by a variety of issues, including narrowed heart arteries, cardiac rhythm disturbances or dysfunction of the heart valves or the heart muscle itself. Luckily, for many of these patients, the cardiac imaging tools that physicians use to diagnose and plan treatments for such heart diseases are constantly evolving, driving changes to physician training methods, to the choice of patient treatments and even to improving outcomes by providing real-time ‘line-of-sight’ guidance. With so many exciting resources at cardiologists’ disposal, the future of cardiac imaging technologies is already here.
Virtual reality and remote techniques for training and proctoring
In the past, learning to use advanced medical technologies or perform novel procedures could be time-consuming and expensive. One of the unintended consequences of the global COVID-19 pandemic has been the growth in remote methods of teaching and training, and this has been particularly felt in the cardiology space. For novel procedures, several dedicated platforms for remote proctoring have been deployed in a variety of settings to allow life-saving technologies to reach patients in need when in-person/onsite training has not been feasible.
Similarly, to augment traditional teaching that must still take place in person, virtual reality-enabled training programs have also exploded onto the scene: based on technology developed for gaming, such programs have been embraced particularly by the younger, tech-savvy generation of physicians. Accruing evidence suggests that virtual reality training not only provides a tailored and self-paced method of learning, but also improves engagement, knowledge retention and future accuracy in performing the actual procedure that is being trained. Such active and self-directed learning is preferential to passive didactic methods - think of it like this: a pilot wouldn’t learn to fly a plane by watching an instructional video in isolation - they would utilize hours of flight simulation, and such hours ‘behind the wheel’ can, by corollary in a medical sense, yield dividends for patients and physicians alike.
Intracoronary imaging techniques to guide cardiac procedures
Use of dedicated imaging catheters as an adjunct to conventional angiography (x-ray imaging) can assist in the diagnosis and guide the treatment of narrowing coronary arteries during invasive procedures to treat angina. Optical coherence tomography (OCT) is a red light-based imaging technique that captures high-resolution images when the catheter is placed inside the patient’s heart arteries; the high-quality and granular data thus obtained allows physicians to assess anatomy and execute coronary interventions, such as stent placement, with unrivalled precision. Recent data have indicated that use of OCT can alter physician decision-making over conventional x-ray (angiographic) imaging alone in nearly 90% of cases, illustrating the huge potential such technologies have to improve patient care.
Traditionally, such imaging techniques have been taught via in-person teaching sessions and hands-on experience. This is a labor- and time-intensive process, consuming healthcare systems’ precious resource of physician & team time away from frontline care duties. Virtual reality training programs have already been developed and rolled out to allow physicians to learn OCT at their own pace through experiential learning in an environment similar to that in which they will use these acquired skills. Future directions will likely embrace augmented reality, to move one step further towards online remote access and thereby enable real-time assistance and case-sharing during cardiac procedures – to effectively join physicians across the world and allow them to be ‘in the room’ together.
3D mapping the heart
Away from coronary interventions, novel imaging techniques have also revolutionized diagnosis and treatment of cardiac arrhythmias (heart rhythm disturbances) – 3-dimensional (3D) mapping technologies combine both anatomical and electrical information to enable accurate diagnosis and targeting of therapy to abolish rhythm disturbances.
The synthesis of cross-sectional imaging (for example with computed tomography/CT imaging) performed before the procedure with real-time electrical mapping through dedicated catheters reconstruct a virtual “shell” of the heart’s surface where the electrical and tissue information can be displayed in real time. Such imaging needs to take into account a variety of complex and interacting factors, including heart motion, patient breathing, and directionality of the electrical activation simultaneously, through motion-compensated and model-rendering algorithms that provide physicians with a reference to understand the path and spread of electricity over healthy and diseased heart tissue. This, in turn, enables precision in delivery of therapies to mitigate arrhythmia and minimize risk to patients, whilst reducing radiation exposure to both physician and patient.
Like OCT, the 3D mapping technology is being trained and supported remotely through virtual reality, enabling widespread dissemination of the technique without cumbersome in-person training.
Cardiac imaging and structural heart disease
Advancements in imaging have also enabled a new suite of structural heart therapies. Structural heart diseases are primarily defects of the fabric of the heart itself. They may be congenital or acquired and can affect the heart valves as well as the walls between the heart chambers. Such abnormalities can progress with time and impact the heart’s ability to pump blood effectively and efficiently, preventing maintenance of a heathy circulation. Historically, structural heart diseases have been markedly undertreated, in no small part due to the need for open heart surgery to correct these problems. This problem is growing with increasing recognition and diagnosis of structural heart diseases and, with a globally aging population, degenerative (structural heart) diseases are increasing in prevalence. This has driven the development of trans-catheter (minimally invasive) techniques to correct or improve such conditions, expanding treatment opportunities for some patients who may not be candidates for open or conventional surgical treatment.
Of course, such therapies cannot exist in isolation and have required new modes of visualization (imaging) to facilitate these novel transcatheter therapies both in terms of planning the procedure but also of imaging guidance to facilitate the best possible outcome from the procedure. Developments in both CT scanning and echocardiography, encompassing real time 3-dimensional reconstruction, have enabled this new era of interventions.
Cardiac imaging technologies are rapidly advancing and are driving improved patient care and enabling novel and less invasive therapies across the spectrum of structural heart abnormalities, coronary artery disease and cardiac arrhythmias. With the advent of virtual reality-enhanced learning and remote proctoring technologies, more widespread uptake of the available life-enhancing therapies can be achieved even at a time where physicians and their teams cannot travel to learn them. These examples illustrate the possibilities when the envelope of innovation and technology can be pushed to enhance personalized cardiac care for individual patients.
About the author: Dr. Nick West is the chief medical officer and divisional vice president of medical affairs, vascular, at Abbott.