AI Spotlight: Guiding Heart Disease Diagnosis Through Transformer Models

Akhil Vaid, MD, left, and Girish Nadkarni, MD, MPH, right, are working to make artificial intelligence models more feasible for reading electrocardiograms, using a novel transformer neural network approach.

Electrocardiograms (ECGs) are often used by health providers to diagnose heart disease. At times, irregularities in the recordings are too subtle to be detected by human eyes but can be identified by artificial intelligence (AI).

However, most AI models for ECG analysis use a particular deep learning method called convolutional neural networks (CNNs). CNNs require large training datasets to make diagnoses, which spell limitations when it comes to rare heart diseases that do not have a wealth of data.

Researchers at the Icahn School of Medicine at Mount Sinai have developed an AI model, called HeartBEiT, for ECG analysis, which works by interpreting ECGs as language.

The model uses a transformer-based neural network, a class of network that is unlike conventional networks but does serve as a basis for popular generative language models, such as ChatGPT.

Here’s how HeartBEiT works as an artificial intelligence deep-learning model, and how it compares to CNNs.

HeartBEiT outperformed conventional approaches in terms of diagnostic accuracy, especially at lower sample sizes. Study findings were published in npj Digital Medicine on June 6. Akhil Vaid, MD, Instructor of Data-Driven and Digital Medicine, was lead author, and Girish Nadkarni, MD, MPH, Irene and Dr. Arthur Fishberg Professor of Medicine, was senior author.

In this Q&A, Dr. Vaid discusses the impact of this new AI model on reading ECGs.

What was the motivation for your study?

Deep learning as applied to ECGs has had much success, but most deep learning studies for ECGs use convolutional neural networks, which have limitations.

Recently, the transformer class of models has assumed a position of importance. These models function by establishing relationships between parts of the data they see. Generative transformer models such as the popular ChatGPT utilize this understanding to generate plain-language text.

By using another generative image model, HeartBEiT creates representations of the ECG that may be considered “words,” and the whole ECG may be considered a single “document.” HeartBEiT understands the relationship between these words within the context of the document, and uses this understanding to perform diagnostic tasks better.

What are the implications?

Our model forms a universal starting point for any ECG-based study. When comparing our model to popular CNN architectures on diagnostic tasks, HeartBEiT ended up with equivalent performance and better explanations for the model’s thinking and choices using as little as a tenth of the data required by other approaches.

Additionally, HeartBEiT generates very specific explanations of which parts of an ECG were most responsible for pushing a model towards making a diagnosis.

What are the limitations of the study?

Pre-training the model takes a fair amount of time. However, fine-tuning it for a specific diagnosis is a very quick process that can be accomplished in a few minutes.

HeartBEiT was compared against other conventional AI methods on diagnostic measures, including left ventricular ejection fraction ≤40%, hypertrophic myopathy, and ST-elevation myocardial infarction, and was found to perform better.
How might these findings be put to use?

Deployment of this model and its derivatives into clinical practice can greatly enhance the manner in which clinicians interact with ECGs. We are no longer limited to models for commonly seen conditions, since the paradigm can be extended to nearly any pathology.

What is your plan for following up on this study?

We intend to scale up the model so that it can capture even more detail. We also intend to validate this approach externally, in places outside Mount Sinai.


Learn more about how Mount Sinai researchers and clinicians are leveraging machine learning to improve patient lives

AI Spotlight: Forecasting ICU Patient States for Improved Outcomes

When Can a Patient Come Off a Ventilator? This AI Can Help Decide

AI Spotlight: Forecasting ICU Patient States for Improved Outcomes

AI Spotlight: Forecasting ICU Patient States for Improved Outcomes

Girish Nadkarni, MD, MPH, and Faris Gulamali

Artificial intelligence (AI) and machine learning (ML) have seen increasing use in health care, from guiding clinicians in diagnosis to helping them decide the best course of treatment. However, AI still has much unrealized potential in various health care settings.

Mount Sinai researchers are exploring bringing AI into intensive care, and developed Spatial Resolved Temporal Networks (SpaRTeN), a model to assess high-frequency patient data and generate representations of their state in real time.

The work was presented at the Time Series Representation Learning for Health workshop on Friday, May 5, hosted by the International Conference for Learned Representations, a premier gathering dedicated to machine learning.

Hear from Girish Nadkarni, MD, MPH, Irene and Dr. Arthur Fishberg Professor of Medicine at the Icahn School of Medicine at Mount Sinai and the leader of the SpaRTeN research, and Faris Gulamali, medical student at Icahn Mount Sinai and member of the Augmented Intelligence in Medicine and Science lab, on what lay behind creating the model and what it could achieve for patients.

What was the motivation for your study?

A growing amount of research is indicating the need to redefine critical illness by biological state rather than a non-specific illness syndrome. Advances in genomics, data science, and machine learning have generated evidence of different underlying etiologies for common ICU syndromes. As a result, patients with the exact same diagnosis can have entirely different outcomes.

What are the implications?

In the ICU, representations of a patient can be used to guide personalized treatments based on personalized diagnoses rather than generic treatments with empirical diagnoses.

What are the limitations of the study?

In this study, we only looked at using one type of data at a time in real time. For example, we looked primarily at measures of intracranial pressure. However, the ICU has many types of data being output simultaneously. Future work hopes to integrate all the different types of data such as electrocardiograms, blood pressure, and imaging to improve patient representations.

How might these findings be put to use?

These patient representations are being combined with data on medications and procedures to determine how to optimize patient treatment based on underlying state rather than common illness syndromes.

What is your plan for following up on this study?

In this study, we focused primarily on creating the algorithm and showing that it works for the case of intracranial hypertension. In future studies, we would like to integrate multiple data modalities such as imaging, electrocardiograms, and blood pressure as well as intervention-based data such as medications and procedures to determine precise empirical interventions that lead to improvements in short-term and long-term patient outcomes.


Learn more about how Mount Sinai researchers and clinicians are leveraging machine learning to improve patient lives

Computational Neuroscientist Opens Doors for New Ideas and Talent to Thrive

When Can a Patient Come Off a Ventilator? This AI Can Help Decide

Using Technology to Enhance Care: A Talk With Robbie Freeman, RN, MSN, Vice President of Digital Experience and Chief Nursing Informatics Officer

A portrait of Robbie Freeman, RN, MSN, NE-BC

Robbie Freeman, RN, MSN, NE-BC

The convergence of digital technology, artificial intelligence (AI), and informatics is revolutionizing the health care landscape, bringing forth unprecedented opportunities to transform health care. For the nursing and clinical community, this evolution presents a chance to enhance practice, streamline workflows, and improve outcomes.

In health care, AI typically refers to the ability of computers to independently convert data into knowledge to guide decisions or autonomous actions. AI can provide support for nurses that includes risk prediction, clinical decision support, mobile health technology, and voice assistants. Each of these augments nursing practice and has the potential to transform health care.

Robbie Freeman, RN, MSN, NE-BC, is Vice President of Digital Experience and Chief Nursing Informatics Officer (CNIO) at the Mount Sinai Health System. Mr. Freeman leads a team of experts who function much like translators—acting as conduits between clinicians and technology teams. As a system Vice President, he leads the digital experience and clinical data science teams that have built out a portfolio of digital and AI products. When it comes to the development of AI tools, he says, “This team is one of the leading data science teams in the country in terms of the scale and impact.”

Mr. Freeman began his nursing career at Mount Sinai in 2009 as a bedside medical-surgical nurse. As he moved into management and leadership roles, he became particularly interested in systems and how they functioned to support nurses and other health care staff.

In 2015, Mr. Freeman moved into a newly created position in technology and quality to develop a vision for how Mount Sinai could use technology and improve patient experiences. As Vice President of Clinical Innovation at The Mount Sinai Hospital, he built machine learning products to improve patient safety and hospital operations while also serving as administrator for the Emergency Department and Respiratory Care. Beth Oliver, DNP, RN, FAAN, Senior Vice President, Cardiac Services, and Chief Nurse Executive at Mount Sinai Health System, along with Kristin Myers, MPH, Executive Vice President and Chief Digital and Information Officer, shifted Mr. Freeman’s role to that of a systemwide Vice President for Digital Experience, and named him the Chief Nursing Informatics Officer in 2021.

“I oversee three teams,” he says. “In my CNIO role, I oversee our nursing informatics program. We have nurses embedded in our hospitals, ambulatory setting, and service lines.”

Mr. Freeman is pursuing his doctorate in nursing practice at Yale University, where his research interest is the application of artificial intelligence products to reduce health disparities. He holds a Master of Science in Business Analytics from New York University’s Stern School of Business and a Master of Science in Nursing from Excelsior University, New York, specializing in clinical systems management. He is also a graduate of the Mount Sinai Phillips School of Nursing, where he serves on the Board of Trustees.

“I did not study computer science, but I’ve always had a passion for leveraging technology to solve problems,” he says. “My father was an artist and founded a photo retouching company here in New York City. Teams of artists would manually retouch photos by hand in a long, complex process. Growing up, I watched his company get revolutionized by computerized photo-editing technology. That showed me how technology can transform an entire industry; the people and processes had to evolve drastically. Looking back, this early life experience shaped my world view for reimagining systems and processes through technology.”

Mr. Freeman is the chair of the American Nurses Association’s (ANA) Innovation Advisory Board. “I’ve been working on advocacy nationally with the ANA for the safe and ethical use of AI. One of the things we have done at Mount Sinai was implement an overarching governance structure to make sure the tools we develop, and the vendors we partner with, think about the ethical use of this technology.” He adds, “We do not want to create disparities. We need to be sure AI tools do not disenfranchise minorities and at-risk communities.”

Social determinants of health are incorporated into the CNIO strategic plan and included in the work of the nursing informatics team. “We take a co-design approach with our front-line team to create tools that allow us to get the right resource to the right patient at the right time,” says Mr. Freeman. “These efforts have resulted in an AI tool that identifies malnourished patients who would benefit from a registered dietitian consult, and an AI-driven assessment tool that identifies patients at higher risk for falls. These innovations allow nurses and other providers to focus their time and energy on those patients who will benefit from specialized care.”

Mr. Freeman has described the opportunity for artificial intelligence applied to nursing processes as “precision nursing,” a technology that can support nurses in their practice. “One of the things we recently rolled out on pilot units at two hospitals is voice system AI so we can use voice-based assistants to help our nurses with tasks,” he says. “This technology enables voice-based documentation to free up our nursing team from manual documentation.”

Mr. Freeman and his team have created a road map for digital transformation across the Health System. “We have disseminated mobile phones to nurses in every Mount Sinai Emergency Department, so they have the tools needed to support their practice,” he says. “We are in the process of expanding further into the hospitals later this year.”

“When we talk to patients we hear about gaps, including patients not being sure when to seek care, or follow up with their primary care provider, or schedule an appointment,” says Mr. Freeman. “Our team turned the feedback into a digital advisor, a product that can help patients navigate where they need to go if they are experiencing symptoms, and then based on those symptoms, provide options for patients to be able to make informed decisions.”

“Nursing plays a critical part in providing education for patients following a visit or stay in the hospital. With artificial intelligence and digital, we can really supercharge that work and scale our impact and patient outcomes.”

A Generous Gift Advances Breast Cancer Screening at Mount Sinai

Joyce Glasgold and her daughter, Ellen Glasgold Lange, know firsthand how important early detection can be in breast cancer, which is why a generous gift from the Glasgold Family Foundation made possible the purchase of an ultrasound reading platform powered by artificial intelligence. From left: Alexandra Lange, Ellen Glasgold Lange, Joyce Glasgold, Olivia Lange, and Trevor Lange.

When it comes to breast cancer, Joyce Glasgold and her daughter, Ellen Glasgold Lange, know firsthand how important early detection can be.

Joyce Glasgold’s mother died of breast cancer, and many of her family members had the disease. Mrs. Glasgold herself was diagnosed in 1991 at age 50. Fifteen years later, her daughter Ellen was diagnosed with lobular carcinoma in situ (LCIS), a condition that indicates an increased risk of developing breast cancer and that, along with her family history, led her to have a bilateral mastectomy.

So when they learned about Koios DS Breast—an AI-powered, ultrasound-reading software platform that can spot cancer in two seconds—they were eager to make it available to women throughout New York City. A generous gift from the Glasgold Family Foundation to the Department of Radiology supported the purchase and installation of the software at The Mount Sinai Hospital, ensuring that physicians have advanced technology to aid them in making rapid, accurate diagnoses and reducing unnecessary biopsies.

This is particularly important for women with dense breasts, which can make it much more difficult to spot cancers. Nearly 50 percent of women over age 40 have dense breast tissue, and mammograms miss more than half of cancers present in those individuals. These women often require an ultrasound in addition to mammography to capture images of areas of the breast that may be harder to see.

“This new software potentially allows us to increase the ability of breast ultrasound to find cancer that might have gone undetected,” says Laurie R. Margolies, MD, FACR, FSBI, System Chief of Breast Imaging for the Mount Sinai Health System. “The radiologists at Mount Sinai are excited to be able to use cutting-edge technologies for the betterment of our robust ultrasound screening program and the benefit of all our patients.”

Using artificial intelligence and machine learning algorithms, Koios DS Breast compares ultrasounds to an archive of hundreds of thousands of images from patients from around the world with confirmed benign or malignant diagnoses, providing radiologists with an instant “second opinion” in classifying suspicious lesions. The technology not only helps clinicians identify cancer sooner so patients can begin treatment as quickly as possible, but it also reduces the need for biopsies in benign tissues.

Because the Mount Sinai Health System serves a large and diverse patient population, the Glasgolds are also pleased that women from medically underserved communities will now have access to state-of-the-art diagnostics.

“We all know that catching breast cancer early saves lives, so our family was compelled to accelerate the adoption of this exciting new innovation,” says Joyce Glasgold. “We are honored and thrilled to help bring this game-changing technology to Mount Sinai.”

How Conducting Research in Artificial Intelligence Through the Master of Science in Clinical Research Program Puts Olivia Cullen on a Physician-Scientist Path

When Olivia Cullen graduated from college, she had two career goals: to become a physician and to perform impactful clinical research. Believing she was not ready to apply to medical school, she instead decided to pursue a Master of Science in Clinical Research (MSCR) degree at the Graduate School of Biomedical Sciences at the Icahn School of Medicine at Mount Sinai.

“For me, the MSCR program was an opportunity to understand the inner workings of clinical research to discover what interested me most,” Ms. Cullen says. “Ultimately, I fell in love with data science research, and now I’m about to begin an MD/PhD program at Mount Sinai with a concentration in Artificial Intelligence and Emerging Technologies in Medicine.” The Graduate School is launching this new concentration in Fall 2022, and Ms. Cullen is in the first cohort of students.

Under the leadership of renowned physician-scientist Girish N. Nadkarni, MD, MPH, Ms. Cullen classified data collected from electrocardiograms (ECG) in the Augmented Intelligence in Medicine and Science Laboratory (AIMS), which is part of the Mount Sinai Clinical Intelligence Center (MSCIC). Among her accomplishments was the creation of an algorithm to help identify patients with a rare heart condition known as hereditary transthyretin amyloidosis (haTTR). She worked closely with Dr. Nadkarni, who is Co-Director of the MSCIC and Clinical Director of the Hasso Plattner Institute for Digital Health at Mount Sinai, and with Akhil Vaid, MD, who is a postdoctoral scholar in Dr. Nadkarni’s lab.

“My ultimate goal as a researcher is to use the vast amount of health care data we have been accumulating to better the lives of patients,” she says. “Specifically, I am fascinated by the applications of computer vision in the field of health care, and I want to improve analysis of medical imaging.”

Although Ms. Cullen completed her degree remotely from her home in New Jersey, she remained very close to the Mount Sinai community. “The connection I made with my advisors completely changed the course of my career,” she says. “They helped me get my foot in the door with data science research, and then they really advocated for me, helped me take the next steps in my career, and even helped me with my medical school applications.”

She also worked, she says, with a number of “really brilliant data science researchers” in the Targeted Healthcare Innovation Fellowship (THRIVE), which was created to address COVID-19-related health problems. She additionally participated in the Mount Sinai Innovation Partners Bootcamp to test an app she created to monitor COVID-19 patients. “I never actually got it off the ground, but it was an amazing experience because I learned a lot about what goes into developing medical technology and I will use those skills going forward in my career.”

As much as she enjoys clinical research, Ms. Cullen also immerses herself in understanding patient care and interaction, volunteering 10 hours a week as an emergency medical technician near her home. “Part of the reason that I find the MD portion of my degree so important,” she says, “is that I would like to have a specialty that will inform my research and ultimately help the people that I’m trying to serve.”

 

Computational Neuroscientist Opens Doors for New Ideas and Talent to Thrive

Computational Neuroscientist Opens Doors for New Ideas and Talent to Thrive

When Kanaka Rajan, PhD, an expert in neural networks, joined the Icahn School of Medicine at Mount Sinai in late 2018, it was the school’s way of investing in computational neuroscience. But since establishing her lab, she has achieved new heights not just in her area of study, but in paving roads for future diverse talents to enter what had been a rather homogenous field.

Dr. Rajan, an Assistant Professor of Neuroscience in The Friedman Brain Institute at Icahn Mount Sinai, was recently awarded the McKnight Scholar Award, a three-year honor that provides funding to early-career scientists, from the McKnight Foundation, a Minnesota-based organization that has supported work in arts and culture, neuroscience, and climate change.

“I am honored to be recognized by the McKnight Foundation this year. The announcement was such a pleasant surprise,” said Dr. Rajan. Awardees of such programs are not often pure theorists like herself, she said. But the less restricted nature of the funding will advance a new research direction her lab has taken on and will bring much needed exposure to a key problem in science: how does the brain work?

Growing the team

The Rajan lab builds recurrent neural networks—artificial networks of neural nodes or regions inspired by biological brains—toward two core goals. The first is to discover the pattern of cell activity and connectivity in the brain, especially in psychiatric disease models, using these networks. These include exploring how there might be unexpected similarities or differences across species.

One study in that vein was based on what Dr. Rajan calls “functional motifs”—brainwide neural maps that tracked motor dysfunction as a correlated passive coping mechanism, a trait associated with depression.

Larval zebrafish subjected to persistent stress were observed to shut down movement. By comparing computational models of the fish’s neural circuitry against what is known in similar studies in mice and humans, Dr. Rajan could extrapolate how multi-area brain communication and connectivity leads to behavior relevant to neuropsychiatric disease.

The second goal is studying the concept of generalized learning, in which skills learned for one task become applicable to other unrelated problems. This encompasses, among other things, how animals and people are able to multitask, and yet, unlike machines built with artificial intelligence, how people can fail to complete all or some of these tasks perfectly.

A recent breakthrough in generalized learning that Dr. Rajan is working on is getting recurrent neural networks to do “curriculum learning”—training them on designed syllabi of increasingly complex tasks.

The idea of curriculum learning is not new in psychology or cognitive neuroscience, in which animals learn through “shaping.” In a lab setting, animals can be shaped to perform a desired task through reinforcement, for example by rewarding successful completion of sequences of smaller tasks.

An illustrated look at Dr. Rajan’s work

Illustration credit: Jorge Cham

Using this method for recurrent neural networks was born partly out of recognition for how animals and children learn, and in part to address limitations of current training algorithms, Dr. Rajan said. She adds that her lab is among a handful to use curriculum learning in neuroscience, recognizing that understanding how people generalize requires understanding their full learning trajectory.

“It’s an exciting new chapter for this field and I’m hopeful the McKnight Scholar Award will help scale our efforts on this front,” Dr. Rajan said. Her team—comprising four postdoctoral researchers, some of whom are starting independent faculty positions later this year, and three graduate students—looks to add a few more members with the funding.

“This is a competitive field and city to hire scientists in,” she said. “Not only are we competing with other institutions; we’re also competing with industry, so it’s on us to make it an attractive proposition.”

But Dr. Rajan believes Mount Sinai offers something that other institutions or industry players might not: complete intellectual freedom.

“When I first arrived, I was told, ‘Welcome to the department. Let us know if you need anything,’ without any restrictions on my next steps,” Dr. Rajan recalled of her interactions with leadership in the Department of Neuroscience at Icahn Mount Sinai. “This was unlike previous institutions I had been at, where I had been gently nudged where I could or could not direct my research.”

Mapping new paths ahead

Just as Dr. Rajan felt she was given the opportunity to excel as a woman and person of color, she felt compelled to extend those opportunities to those who follow in her footsteps.

Dr. Rajan was allowed to tap her seed funding to start a pilot project in which she turned complex research papers into comic strips to get high school seniors and college students, especially those from disadvantaged communities, interested in joining the neuroscience field.

 

A peek at how Dr. Rajan makes complex research topics accessible to young students

Illustration credit: Jordan Collver

“There had been artificially high barriers to entry, like girls had been told they’re not good at math, or that AI and/or computational neuroscience are beyond their understanding,” Dr. Rajan said.

By turning complex ideas into jargon-free and engaging formats such as a comic strip, she hopes to help young students realize that they too can enter and flourish in such a technical field. A series of comic strips have been created and steps are underway to distribute them to schools in New York City and other cities.

“When I first started my lab, I had 116 applications to join my team. Guess how many were women?” Dr. Rajan asked. “Two. Computational neuroscience has a representation problem, and I want to fix what I can.” She continued, “I’ve taken small steps, but the ball rolled from Mount Sinai. Here, you see women really get to thrive.”

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