But new research from Northwestern Medicine suggests the scan may provide its greatest benefit to a narrower group of patients than previously assumed.

Researchers followed more than 6,000 adults for 10 years and found that, for the overall study population, adding a coronary artery calcium score provided only a small improvement over PREVENT, the American Heart Association’s primary cardiovascular risk calculator.

How Heart Calcium Scans Measure Risk

PREVENT estimates a person’s chance of developing cardiovascular disease over the next 10 or 30 years using commonly available health information (such as blood pressure, cholesterol, age, and sex).

A coronary artery calcium scan takes a different approach. The CT scan looks for calcium-containing plaque inside the coronary arteries. The resulting calcium score reflects the amount of detectable calcified plaque. In general, a higher score is associated with a greater risk of future cardiovascular disease.

The new findings suggest that calcium scores become particularly useful when PREVENT initially places someone in a borderline or intermediate risk category. Among these patients, the additional scan provided a clearer indication of who was more likely to develop cardiovascular disease and who was less likely.

“Coronary artery calcium scans are becoming more widely available and less expensive,” said study senior author Dr. Nilay Shah, assistant professor of medicine in the division of cardiology at Northwestern University Feinberg School of Medicine. “Our findings suggest that not everyone necessarily needs or would benefit from a coronary artery calcium scan for the purpose of predicting risk of heart attack and stroke.”

Shah said the findings also highlight potential downsides of using the scans when they are unlikely to change a patient’s treatment.

“Routinely using a calcium scan in people who are at low risk may result in unnecessary radiation exposure, testing and costs with unclear clinical benefits,” Shah added. “Using calcium scans in people who are at high risk is likely to result in unnecessary testing because these individuals are recommended to start a statin regardless of what the calcium scan shows.”

The study was published on Aug. 26 in JAMA.

Comparing Predictions With Real Outcomes

To investigate how much additional information calcium scans provide, Shah and his colleagues examined data from more than 6,000 adults ages 45 to 79 who participated in the Multi-Ethnic Study of Atherosclerosis.

At the beginning of the study, each participant received both a coronary artery calcium score and a PREVENT estimate of their likelihood of experiencing a cardiovascular event within the following 10 years.

Researchers then tracked what actually happened.

Over the next decade, 6% of the participants experienced either a heart attack or stroke. When the team compared predictions that included calcium scores with those based on PREVENT alone, the overall improvement was modest.

The model’s discrimination, which measures how effectively it distinguishes between people who will and will not experience a cardiovascular event, increased only slightly. It rose from 0.73 using PREVENT to 0.75 when calcium scores were included.

The picture changed, however, when researchers focused specifically on people whose initial PREVENT scores placed them in the borderline or intermediate risk categories (those initially deemed to have a 3% to 9% risk of heart disease within 10 years).

For this group, including the calcium score produced a more meaningful improvement in predicting future cardiovascular events.

“For patients at borderline risk, knowing their calcium score can help determine whether their risk is actually lower or higher than initially estimated, which can help guide treatment decisions,” Shah explained.

Finding the Patients Most Likely to Benefit

About 10% of U.S. adults age 30-79 have cardiovascular disease, which remains the nation’s leading cause of death. Yet many heart attacks, strokes and other cardiovascular events can be prevented, Shah said.

Accurately identifying a person’s risk can help doctors determine who is most likely to benefit from preventive treatments, including statins, which lower cholesterol and reduce cardiovascular risk.

“The findings help us understand how best to use the available tools to estimate someone’s risk of a heart attack or stroke. That provides more precise guidance for who is most likely to benefit from using a statin to help prevent heart disease,” Shah said.

Shah added that the results also support the clinical usefulness of the relatively new PREVENT calculator. Even without calcium scan results, PREVENT performed well at predicting cardiovascular risk.

Questions That Still Need Answers

The researchers said additional studies are needed to determine how much calcium scores improve PREVENT estimates in certain populations.

That includes higher risk groups such as South Asian and Filipino adults, Shah noted. More research is also needed in younger people because participants in this study were between ages 45 and 79 when the research began.

Other Northwestern co-authors are Xiaoning Huang, Lucia Petito, Norrina Allen, Dr. Philip Greenland and Dr. Sadiya Khan.

The study is titled, “Predictive Utility of Coronary Artery Calcium Added to the PREVENT Atherosclerotic Cardiovascular Disease Equations.” It was supported by the American Heart Association (grant 24CDA1266732) and the National Heart, Lung, and Blood Institute (contracts 75N92020D00001, HHSN268201500003I, N01-HC-95159, 75N92020D00005, N01-HC-95160, 75N92020D00002, N01-HC-95161, 75N92020D00003, N01-HC-95162, 75N92020D00006, N01-HC-95163, 75N92020D00004, N01-HC-95164, 75N92020D00007, N01-HC-95165, N01-HC-95166, N01-HC-95167, N01-HC-95168, N01-HC-95169 and grant K23HL157766).

The advance, developed in the lab of Marko Lončar, Tiantsai Lin Professor of Electrical Engineering, could support the development of compact quantum networks built directly onto chips. It may also help enable hybrid quantum systems that combine several different kinds of quantum bits, or qubits.

The findings are published in Nature Physics. The experiments were led by Eliza Cornell, a recent Ph.D. graduate from the Lončar lab who is now a postdoctoral researcher at Boston University, and Zhujing Xu, a former postdoctoral scholar in Lončar’s group.

Using Sound to Carry Quantum Information

One promising approach to quantum networking uses the spin of an electron, associated with impurity in diamond, to store quantum information. Tiny packets of mechanical vibration called phonons can then serve as carriers that move information between qubit nodes.

The Lončar lab has played a major role in exploring the potential of these systems. Among its advances is a structure known as a phononic cavity, which traps mechanical vibrations so they can interact more strongly with the electron spin inside a qubit.

Phonons may have important advantages over light, which is more commonly used to move quantum information across chip-scale networks. At the same frequency, phonons have much shorter wavelengths than light, making it possible to build considerably smaller components and pack them more tightly together.

Phonons also interact readily with both solid-state spins and electromagnetic fields. That versatility makes them especially attractive for hybrid quantum technologies that bring together different types of qubits in a single system.

The Challenge of Preserving Quantum Memory

Using phonons, however, creates a major difficulty: protecting quantum memory.

Qubits are extremely sensitive to disturbances from their surroundings. To remain useful, they must preserve their quantum state long enough to store and process information. This ability is known as coherence.

Researchers often protect quantum memories from environmental interference using microwave pulses that separate, or decouple, the memory from surrounding noise. Those techniques do not work particularly well for qubits placed inside phononic cavities.

That limitation has made it difficult to achieve both strong interaction with phonons and long-lasting quantum memory in the same device.

“Dressed” Qubits Protected by Sound

The SEAS team addressed the problem by demonstrating what they describe as “all-mechanical coherence protection” for a silicon-vacancy spin in diamond.

Instead of relying on conventional microwave pulses, the researchers continuously applied a mechanical driving field made from phonons. This changed the qubit into a different kind of quantum state known as a “dressed” qubit.

The term “dressed” refers to the qubit effectively “wearing” a continuous acoustic field. In this condition, the qubit becomes less vulnerable to low-frequency noise from its surroundings.

Because the protection comes from a continuous mechanical field that is compatible with phononic cavities, the technique could operate inside the same structures that may eventually connect stationary nodes in quantum networks.

That gives phonons a potentially powerful dual role. They could transport quantum information between different parts of a network while simultaneously helping protect that information from environmental noise.

“We are solving two problems,” Cornell said. “We want the spin to have strong interaction with phonons, and we want the spin to have a long coherence time. Our paper demonstrates a method of extending the coherence time that is compatible with the silicon-vacancy center being in a cavity.”

Quantum Coherence Lasts About Three Times Longer

With the new method, the researchers increased the coherence time of the silicon-vacancy spin by roughly a factor of three.

The result demonstrates that continuous-wave mechanical noise suppression can extend quantum coherence in real devices, suggesting that microscopic sound waves could become an important tool for building more reliable and compact quantum systems.

“All-mechanical coherence protection and fast control of a spin qubit” was co-authored by Zhaoyou Wang, Hana K. Warner, Eliana Mann, Michael Haas, Smarak Maity, Graham Joe, Liang Jiang, Peter Rabl, and Benjamin Pingault.

The research received U.S. federal support from: the National Science Foundation under grant number EEC-1941583; the Air Force Office of Scientific Research under award numbers FA9550-23-1-0333 and FA9550-23-1-0338; and Q-NEXT, a U.S. Department of Energy Office of Science National Quantum Information Science Research Centers under award No. DE-FOA-0002253.

The work was performed in part at the Harvard Center for Nanoscale Systems, a member of the National Nanotechnology Infrastructure Network, which is supported by National Science Foundation award No. ECS-0335765.

The Harvard Office of Technology Development is actively pursuing patent protection and commercialization opportunities for the innovations arising from this research.

Researchers at the University of California, Berkeley compared semaglutide directly with calorie restriction, one of the best-known interventions for extending lifespan in laboratory animals. The drug reproduced many of the anti-aging effects of eating less, but in several important areas, it appeared to go even further.

The findings raise an intriguing possibility: GLP-1 drugs may influence the aging process itself. Earlier animal studies have shown that these drugs can delay the onset of multiple age-related diseases. If semaglutide acts on biological mechanisms that drive aging, that could help explain why GLP-1 treatments have shown benefits across such a wide range of health conditions.

“Most chronic diseases are deeply rooted in the aging process. If GLP-1 agonists do indeed slow it down, then a wide range of clinical benefits is exactly what you’d expect to see,” said Rafael de Cabo, Ph.D., a senior investigator at the NIH’s National Institute on Aging (NIA), and author of a commentary on the new study.

Testing Semaglutide Late in Life

To see what semaglutide could do when aging was already well underway, a research team led by Danica Chen, Ph.D., gave the drug to 20-month-old female mice for three months.

Compared with untreated mice, the animals receiving semaglutide showed better muscle and cognitive function. Gene activity also revealed improvements in several biological features associated with aging, including reduced inflammation and less decline in the body’s ability to repair and regenerate tissue.

The lifespan results were especially striking. In a separate group treated with semaglutide until death, median lifespan was nearly 100 days longer than in untreated mice.

Was Eating Less the Real Reason?

Because semaglutide reduces appetite, the researchers wanted to know whether the apparent anti-aging effects simply came from consuming fewer calories.

To test that idea, they directly compared semaglutide with calorie restriction. For five months, one group of 20-month-old female mice received semaglutide, while another was placed on a 24% calorie-restricted diet designed to match how much the treated mice were eating.

The two approaches produced many similar effects, and most physiological measurements remained stable. But semaglutide stood out in several areas.

Mice receiving the drug improved beyond their starting levels in exploratory behavior, spatial memory, and blood-sugar maintenance. Their metabolic rate also remained largely unchanged, while metabolism slowed in the calorie-restricted animals.

Those differences suggest that semaglutide may be doing more than simply recreating the effects of eating less.

“These differences point to the possibility that GLP-1 drugs tap into a biological pathway independent of calorie restriction. Uncovering this potential route and the benefits that may specifically stem from it is an important direction for future research into the development of longevity-enhancing interventions,” said Chen, corresponding author of the study and professor of metabolic biology and nutrition at UC Berkeley.

Could GLP-1 Drugs Affect Human Aging?

The findings could open new directions in longevity research, but they do not show that Ozempic, Wegovy, or other GLP-1 drugs can extend human lifespan.

Additional clinical research will be needed to determine whether the effects seen in mice translate to people. One example is the recent post-hoc analysis of the SLIM LIVER trial, but further studies will be necessary to establish whether GLP-1 drugs can meaningfully influence human aging or longevity.

Chen said future clinical studies may also investigate these drugs in healthy older adults. If researchers eventually find similar benefits in people without obesity or diabetes, the potential uses of GLP-1 treatments could broaden considerably.

NIH supported this research through NIA grants R01AG063404, R01AG063389, and R01AG082105.

The research was led by Professor Lu Qi of Tulane University, New Orleans, USA. He said: “Previous observational studies have linked nighttime light exposure with a higher risk of cardiovascular disease, but little is known about the related cardiac structure and functional changes. We carried out this research to find out what happens to the heart over time when people are exposed to too much light at nighttime.”

Tracking Nighttime Light Exposure

The study included 11,071 participants from the UK Biobank. Each person wore a light sensor on their wrist for seven days, allowing researchers to measure how much light they were exposed to during the night.

Three years later, the participants underwent cardiac MRI scans. These detailed images allowed scientists to examine the structure of the heart as well as how effectively it was functioning.

The researchers then compared participants who experienced nighttime light levels above three lux with those who were exposed to almost no light at night.

Changes Found Inside the Heart

People exposed to higher levels of nighttime light showed thickening in the wall of the left ventricle (one of the chambers of the heart). As the wall became thicker, the amount of space inside the chamber was reduced.

The scans also revealed signs that the heart muscle was less able to flex normally during each heartbeat. Reduced flexibility can be an early sign that the heart is beginning to function less effectively. Changes were also detected in the right ventricles and left atria (two other chambers of the heart).

Professor Qi said: “This is the first study of its kind, and it shows that exposure to higher levels of light at nighttime is linked to cardiac remodeling. This is where the structure and function of the heart changes, and we typically see it in response to chronic stress or injury to the heart. It’s our body’s way of adapting to that stress, but ultimately it weakens the heart and can lead to heart failure.

“Light pollution has emerged as a new risk factor for cardiovascular disease. Our findings, together with evidence from other studies, suggest that reduction of nighttime light exposure should be considered as one of the potential strategies for preventing heart disease by clinicians and policy makers.”

Could Darker Bedrooms Help Protect the Heart?

The findings were accompanied by an editorial from Professor Thomas Münzel of University Medical Center Mainz, Germany, and colleagues. They argued that doctors may need to pay more attention to how much light their patients encounter at night, particularly among people already dealing with certain heart conditions.

They said: “It is time for clinicians, particularly those managing patients with heart failure or atrial fibrillation, to start asking about the sleep environment: how dark the bedroom is, whether the patient works night shifts, and how much screen use occurs after sunset. The advice is simple and inexpensive: blackout curtains, warm-coloured bedside lighting, and covering the small standby LEDs on household electronics. From a public health perspective, the implications are larger still. Light pollution is one of the few environmental hazards that cities can control directly and affordably. Shielded fixtures, warm-spectrum bulbs, and dimming or motion-activated streetlights are already available, energy-efficient, and climate-friendly.

“Ultimately, this study is more than an interesting observation. It provides a crucial link between what satellites already show us, i.e. a planet glowing ever brighter at night, and the clinical reality unfolding inside our chests: hearts that are becoming stiffer, weaker, and less efficient. The relationship is biologically coherent, the effect sizes are clinically meaningful, and the dose-response is unambiguous: more light, worse outcomes. The takeaway is clear, darkness deserves recognition as a vital sign, as essential to cardiovascular health as blood pressure control and clean air.”