Posted on by Dr. Francis Collins
As a cardiac electrophysiologist, Deeptankar DeMazumder has worked for years with people at risk for sudden cardiac arrest (SCA). Despite the latest medical advances, less than 10 percent of individuals stricken with an SCA will survive this highly dangerous condition in which irregular heart rhythms, or arrhythmias, cause the heart suddenly to stop beating.
In his role as a physician, DeMazumder keeps a tight focus on the electrical activity in their hearts, doing his best to prevent this potentially fatal event. In his other role, as a scientist at the University of Cincinnati College of Medicine, DeMazumder is also driven by a life-saving aspiration: finding ways to identify at-risk individuals with much greater accuracy than currently possible—and to develop better ways of protecting them from SCAs. He recently received a 2020 NIH Director’s New Innovator Award to pursue one of his promising ideas.
SCAs happen without warning and can cause death within minutes. Poor heart function and abnormal heart rhythms are important risk factors, but it’s not possible today to predict reliably who will have an SCA. However, doctors already routinely capture a wealth of information in electrical signals from the heart using electrocardiograms (ECGs). They also frequently use electroencephalograms (EEGs) to capture electrical activity in the brain.
DeMazumder’s innovative leap is to look at these heart and brain signals jointly, as well as in new ways, during sleep. According to the physician-scientist, sleep is a good time to search for SCA signatures in the electrical crosstalk between the heart and the brain because many other aspects of brain activity quiet down. He also thinks it’s important to pay special attention to what happens to the body’s electrical signals during sleep because most sudden cardiac deaths happen early in the waking hours, for reasons that aren’t well understood.
He has promising preliminary evidence from both animal models and humans suggesting that signatures within heart and brain signals are unique predictors of sudden death, even in people who appear healthy . DeMazumder has already begun developing a set of artificial intelligence algorithms for jointly deciphering waveform signals from the heart, brain, and other body signals [2,3]. These new algorithms associate the waveform signals with a wealth of information available in electronic health records to improve upon the algorithm’s ability to predict catastrophic illness.
DeMazumder credits his curiosity about what he calls the “art and science of healing” to his early childhood experiences and his family’s dedication to community service in India. It taught him to appreciate the human condition, and he has integrated this life-long awareness into his Western medical training and his growing interest in computer science.
For centuries, humans have talked about how true flourishing needs both head and heart. In DeMazumder’s view, science is just beginning to understand the central role of heart-brain conversations in our health. As he continues to capture and interpret these conversations through his NIH-supported work, he hopes to find ways to identify individuals who don’t appear to have serious heart disease but may nevertheless be at high risk for SCA. In the meantime, he will continue to do all he can for the patients in his care.
 Mitochondrial ROS drive sudden cardiac death and chronic proteome remodeling in heart failure. Dey S, DeMazumder D, Sidor A, Foster DB, O’Rourke B. Circ Res. 2018;123(3):356-371.
 Entropy of cardiac repolarization predicts ventricular arrhythmias and mortality in patients receiving an implantable cardioverter-defibrillator for primary prevention of sudden death. DeMazumder D, Limpitikul WB, Dorante M, et al. Europace. 2016;18(12):1818-1828.
 Dynamic analysis of cardiac rhythms for discriminating atrial fibrillation from lethal ventricular arrhythmias. DeMazumder D, Lake DE, Cheng A, et al. Circ Arrhythm Electrophysiol. 2013;6(3):555-561.
Sudden Cardiac Arrest (National Heart, Lung, and Blood Institute/NIH)
Deeptankar DeMazumder (University of Cincinnati College of Medicine)
DeMazumder Project Information (NIH RePORTER)
NIH Director’s New Innovator Award (Common Fund)
NIH Support: National Heart, Lung, and Blood Institute; Common Fund
Posted on by Dr. Francis Collins
More than 3 million people around the world, now tragically including thousands every day in India, have lost their lives to severe COVID-19. Though incredible progress has been made in a little more than a year to develop effective vaccines, diagnostic tests, and treatments, there’s still much we don’t know about what precisely happens in the lungs and other parts of the body that leads to lethal outcomes.
Two recent studies in the journal Nature provide some of the most-detailed analyses yet about the effects on the human body of SARS-CoV-2, the coronavirus that causes COVID-19 [1,2]. The research shows that in people with advanced infections, SARS-CoV-2 often unleashes a devastating series of host events in the lungs prior to death. These events include runaway inflammation and rampant tissue destruction that the lungs cannot repair.
Both studies were supported by NIH. One comes from a team led by Benjamin Izar, Columbia University, New York. The other involves a group led by Aviv Regev, now at Genentech, and formerly at Broad Institute of MIT and Harvard, Cambridge, MA.
Each team analyzed samples of essential tissues gathered from COVID-19 patients shortly after their deaths. Izar’s team set up a rapid autopsy program to collect and freeze samples within hours of death. He and his team performed single-cell RNA sequencing on about 116,000 cells from the lung tissue of 19 men and women. Similarly, Regev’s team developed an autopsy biobank that included 420 total samples from 11 organ systems, which were used to generate multiple single-cell atlases of tissues from the lung, kidney, liver, and heart.
Izar’s team found that the lungs of people who died of COVID-19 were filled with immune cells called macrophages. While macrophages normally help to fight an infectious virus, they seemed in this case to produce a vicious cycle of severe inflammation that further damaged lung tissue. The researchers also discovered that the macrophages produced high levels of IL-1β, a type of small inflammatory protein called a cytokine. This suggests that drugs to reduce effects of IL-1β might have promise to control lung inflammation in the sickest patients.
As a person clears and recovers from a typical respiratory infection, such as the flu, the lung repairs the damage. But in severe COVID-19, both studies suggest this isn’t always possible. Not only does SARS-CoV-2 destroy cells within air sacs, called alveoli, that are essential for the exchange of oxygen and carbon dioxide, but the unchecked inflammation apparently also impairs remaining cells from repairing the damage. In fact, the lungs’ regenerative cells are suspended in a kind of reparative limbo, unable to complete the last steps needed to replace healthy alveolar tissue.
In both studies, the lung tissue also contained an unusually large number of fibroblast cells. Izar’s team went a step further to show increased numbers of a specific type of pathological fibroblast, which likely drives the rapid lung scarring (pulmonary fibrosis) seen in severe COVID-19. The findings point to specific fibroblast proteins that may serve as drug targets to block deleterious effects.
Regev’s team also describes how the virus affects other parts of the body. One surprising discovery was there was scant evidence of direct SARS-CoV-2 infection in the liver, kidney, or heart tissue of the deceased. Yet, a closer look heart tissue revealed widespread damage, documenting that many different coronary cell types had altered their genetic programs. It’s still to be determined if that’s because the virus had already been cleared from the heart prior to death. Alternatively, the heart damage might not be caused directly by SARS-CoV-2, and may arise from secondary immune and/or metabolic disruptions.
Together, these two studies provide clearer pictures of the pathology in the most severe and lethal cases of COVID-19. The data from these cell atlases has been made freely available for other researchers around the world to explore and analyze. The hope is that these vast data sets, together with future analyses and studies of people who’ve tragically lost their lives to this pandemic, will improve our understanding of long-term complications in patients who’ve survived. They also will now serve as an important foundational resource for the development of promising therapies, with the goal of preventing future complications and deaths due to COVID-19.
 A molecular single-cell lung atlas of lethal COVID-19. Melms JC, Biermann J, Huang H, Wang Y, Nair A, Tagore S, Katsyv I, Rendeiro AF, Amin AD, Schapiro D, Frangieh CJ, Luoma AM, Filliol A, Fang Y, Ravichandran H, Clausi MG, Alba GA, Rogava M, Chen SW, Ho P, Montoro DT, Kornberg AE, Han AS, Bakhoum MF, Anandasabapathy N, Suárez-Fariñas M, Bakhoum SF, Bram Y, Borczuk A, Guo XV, Lefkowitch JH, Marboe C, Lagana SM, Del Portillo A, Zorn E, Markowitz GS, Schwabe RF, Schwartz RE, Elemento O, Saqi A, Hibshoosh H, Que J, Izar B. Nature. 2021 Apr 29.
 COVID-19 tissue atlases reveal SARS-CoV-2 pathology and cellular targets. Delorey TM, Ziegler CGK, Heimberg G, Normand R, Shalek AK, Villani AC, Rozenblatt-Rosen O, Regev A. et al. Nature. 2021 Apr 29.
COVID-19 Research (NIH)
Izar Lab (Columbia University, New York)
Aviv Regev (Genentech, South San Francisco, CA)
NIH Support: National Center for Advancing Translational Sciences; National Heart, Lung, and Blood Institute; National Cancer Institute; National Institute of Allergy and Infectious Diseases; National Institute of Diabetes and Digestive and Kidney Diseases; National Human Genome Research Institute; National Institute of Mental Health; National Institute on Alcohol Abuse and Alcoholism
Posted on by Dr. Francis Collins
It was an amazing experience to touch base once again with Kate Rubins, a NASA astronaut aboard the International Space Station. Connecting via live downlink on March 26, 2021, we discussed how space-based research can enable valuable biomedical advances on our planet. For example, over the past five years, NIH’s National Center for Advancing Translational Sciences has funded a series of tissue chip payloads that have launched to the orbiting laboratory. Rubins, who is a biologist and infectious disease expert, has facilitated three of these projects: Cardinal Heart from Stanford University, Electrical Stimulation of Human Myocytes in Microgravity from the University of Florida, and Cartilage-Bone-Synovium from the Massachusetts Institute of Technology.
Posted on by Dr. Francis Collins
There’s been quite a bit of discussion in the news lately about whether to pause or resume college athletics during the pandemic. One of the sticking points has been uncertainty about how to monitor the health of student athletes who test positive for SARS-CoV-2, the novel coronavirus that causes COVID-19. As a result, college medical staff don’t always know when to tell athletes that they’ve fully recovered and it’s safe to start training again.
The lack of evidence owes to two factors. Though it may not seem like it, this terrible coronavirus has been around for less than a year, and that’s provided little time to conduct the needed studies with young student athletes. But that’s starting to change. An interesting new study in the journal JAMA Cardiology provides valuable and rather worrisome early data from COVID-positive student athletes evaluated for an inflammation of the heart called myocarditis, a well-known complication .
Saurabh Rajpal and his colleagues at the Ohio State University, Columbus, used cardiac magnetic resonance imaging (MRI) to visualize the hearts of 26 male and female student athletes. They participated in a range of sports, including football, soccer, lacrosse, basketball, and track. All of the athletes were referred to the university’s sports medicine clinic this past summer after testing positive for SARS-CoV-2. All had mild or asymptomatic cases of COVID-19.
Even so, the MRI scans, taken 11-53 days after completion of quarantine, showed four of the student athletes (all males) had swelling and tissue damage to their hearts consistent with myocarditis. Although myocarditis often resolves on its own over time, severe cases can compromise the heart muscle’s ability to beat. That can lead to heart failure, abnormal heart rhythms, and even sudden death in competitive athletes with normal heart function .
The investigators also looked for more subtle findings of cardiac injury in these athletes, using a contrast agent called gadolinium and measuring its time to appear in the cardiac muscle during the study. Eight of the 26 athletes (31 percent) had late gadolinium enhancement, suggestive of prior myocardial injury.
Even though it’s a small study, these results certainly raise concerns. They add more evidence to a prior study, published by a German group, that suggested subtle cardiac consequences of SARS-CoV-2 infection may be common in adults .
Rajpal and his colleagues will continue to follow the athletes in their study for several more months. The researchers will keep an eye out for other lingering symptoms of COVID-19, generate more cardiac MRI data, and perform exercise testing.
As this study shows, we still have a lot to learn about the long-term consequences of COVID-19, which can take people on different paths to recovery. For athletes, that path is the challenge to return to top physical shape and feel ready to compete at a high level. But getting back in uniform must also be done safely to minimize any risks to an athlete’s long-term health and wellbeing. The more science-based evidence that’s available, the more prepared athletes at large and small colleges will be to compete safely in this challenging time.
 Cardiovascular magnetic resonance findings in competitive athletes recovering from COVID-19 infection. Rajpal S, Tong MS, Borchers J, et al. JAMA Cardiol. 2020 September 11. [Published online ahead of print.]
 Eligibility and disqualification recommendations for competitive athletes with cardiovascular abnormalities: Task Force 3: Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and other cardiomyopathies, and myocarditis. Maron BJ, Udelson JE, Bonow RO, et al. Circulation. 2015;132(22):e273-e280.
 Outcomes of cardiovascular magnetic resonance imaging in patients recently recovered from Coronavirus Disease 2019 (COVID-19). Puntmann VO, Carej ML, Wieters I. JAMA Cardiol. 2020 Jul 27:e203557. [Published online ahead of print.]
Coronavirus (COVID-19) (NIH)
Heart Inflammation (National Heart, Lung, and Blood Institute/NIH)
Saurabh Rajpal (Ohio State College of Medicine, Columbus)