Tracing the start of COVID-19 in GA

At a time when COVID-19 appears to be receding in much of Georgia, it’s worth revisiting the start of the pandemic in early 2020. Emory virologist Anne Piantadosi and colleagues have a paper in Viral Evolution on the earliest SARS-CoV-2 genetic sequences detected in Georgia. Analyzing relationships between those virus sequences and samples from other states and countries can give us an idea about where the first COVID-19 infections in Georgia came from. We can draw Read more

Reddit as window into opioid withdrawal strategies

Drug abuse researchers are using the social media site Reddit as a window into the experiences of people living with opioid addiction. Abeed Sarker in Emory's Department of Biomedical Informatics has a paper in Clinical Toxicology focusing on the phenomenon of “precipitated withdrawal,” in collaboration with emergency medicine specialists from Penn, Rutgers and Mt Sinai. Precipitated withdrawal is a more intense form of withdrawal that can occur when someone who was using opioids starts medication-assisted treatment Read more

CROI: HIV cure report and ongoing research

The big news out of CROI (Conference on Retroviruses and Opportunistic Infections) was a report of a third person being cured of HIV infection, this time using umbilical cord blood for a hematopoetic stem cell transplant. Emory’s Carlos del Rio gave a nice overview of the achievement for NPR this morning. As del Rio explains, the field of HIV cure research took off over the last decade after Timothy Brown, known as “the Berlin patient,” Read more

Arshed Quyyumi

Elevated troponin after exercise refines cardiac risk prediction

High levels of troponin, a sign of acute stress to the heart, in the blood reveal whether someone recently experienced a heart attack. Advances in testing have made it possible to detect much lower levels of troponin — but still elevated above zero. For example, elevated troponin can be detected after strenuous exercise, even in healthy young athletes.

With that exercise-induced response in mind, Emory Clinical Cardiovascular Research Institute investigators have been studying whether high-sensitivity troponin measurements might be used to replace cardiac stress tests. These procedures are expensive and sometimes involve nuclear imaging, which exposes patients to radiation.

A new paper in American Journal of Cardiology shows how elevated high-sensitivity troponin levels in response to exercise on a treadmill can predict future outcomes in patients with coronary artery disease — better than stress tests with imaging.

Read more

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Take heart, Goldilocks — and get more sleep

Sleeping too little or too much increases the risk of cardiovascular events and death in those with coronary artery disease, according to a new paper from Emory Clinical Cardiovascular Research Institute.

Others have observed a similar U-shaped risk curve in the general population, with respect to sleep duration. The new study, published in American Journal of Cardiology, extends the finding to people who were being evaluated for coronary artery disease.

Arshed Quyyumi, MD and colleagues analyzed data from a registry of 2846 patients undergoing cardiac catheterization at Emory. The “sweet spot” appeared to be those who report sleeping between 6.5 and 7.5 hours per night.

39 percent of patients with coronary artery disease reported that they slept fewer than 6.5 hours per night, and 35 percent slept longer than 7.5 hours. For the next few years, both groups had higher risks of all-cause mortality: elevated risk of 45 percent and 41 percent, respectively. Patients were followed for an average of 2.8 years.

The extreme ends of sleep duration both had even higher risk: people who reported less than 4.5 hours per day had almost double mortality risk (96 percent), and those more than 8.5 hours had 84 percent higher mortality risk.

Patients with short sleep durations also had higher cardiovascular mortality (48 percent), but adjusting for cardiovascular risk factors attenuated the association between long sleep duration and CV risk.

A detailed assessment of someone’s sleep can require PSG (polysomnography). In this study,  researchers were able to get information by simply asking about sleep duration.

The participants in the Emory study were simply asked: “How many hours of sleep do you usually get each night (or when you usually sleep)?” This question may not always be answered accurately, since time in bed isn’t necessarily time asleep. Still, the broad strokes show that the sleep-CV health relationship is robust.

“What is most stunning to me are that these data were collected from cardiac patients about to undergo an invasive procedure, who still reported an aspect of their sleep that was meaningful and predictive of future survival,” says Donald Bliwise, PhD, a specialist in sleep and aging research who is a co-author on the Emory study. “Often, epidemiologic studies collect data far away from a clinic setting, where anxiety is less and estimations may be sharper. We have here in this clinical study beautiful evidence that estimates made ‘from the gurney’ may be just as meaningful as those collected in the field.”

Quyyumi says if patients with heart disease are sleeping poorly, it’s important to recognize that they are at higher risk and counsel them regarding getting more sleep, as well as factors that can disrupt sleep, such as caffeine, alcohol and looking at screens late in the day.

More specific treatments may depend what is interfering with high-quality sleep in a given patient. Several conditions can lead to difficulty sleeping, such as sleep apnea, restless leg syndrome, as well as depression, all of which have been linked with heart disease. Physiologically, several mechanisms are probably exerting their effects, such as weakening circadian rhythms and sleep fragmentation with aging, and obesity/metabolic syndrome driving inflammation. Read more

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Racial disparities in a CV biomarker

Because circulating progenitor cells repair blood vessels, they are a measure of regenerative capacity in the cardiovascular system. Cardiologist Arshed Quyyumi, MD and his colleagues at Emory Clinical Cardiovascular Research Institute have intensively studied this cell type as a marker of vulnerability or resilience.

A recent paper from Quyyumi’s team in Circulation Research examines circulating progenitor cells (CPCs) through the lens of racial disparity. The authors find that African-Americans tend to have lower levels of this regenerative biomarker:

In a large well-characterized biracial cohort, we demonstrate that black participants had significantly lower CPC counts compared with whites, even after adjustment for differences in demographic factors and CVD risk factors. These results were validated in an independent cohort. Thus, on average, after adjustment for sex and other CVD risk factors, blacks have CPC levels that are ≈15% to 30% lower compared with whites, even in subjects free of risk factors. CPC levels decline with age, reaching on average half the levels at age 80 compared with age 20. We found that blacks have CPC counts equivalent to those in whites who are 14 years older. CPC levels are higher after AMI as a result of mobilization because of injury. We show for first time that blacks have 30% to 35% lower CPC mobilization in the setting of AMI.

This is a tricky area to study. How many socioeconomic and environmental factors go into the racial disparities of cardiovascular disease risk? Diet. Exercise. Geography, education, access to healthcare. Air pollution. Psychological stress and inflammation associated with discrimination. It is possible to view CPCs as summing up many of these influences, analogous to the way hemoglobin A1C measurements integrate someone’s blood sugar levels over time as a marker of diabetes. Read more

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Elevated (but still low) troponin as a long term cardio biomarker

This weekend (March 10) at the American College of Cardiology meeting, data will emerge on whether expensive and much-discussed PCSK9 inhibitors can lower the risk of heart disease as much as they reduce LDL cholesterol.

To help doctors decide who should take cholesterol-lowering drugs that cost thousands of dollars a year, the focus of discussion could fall on risk models, such as the Framingham sc