What is the most important measurement of cholesterol or lipids in the blood, when it comes to cardiovascular disease risk? LDL-C [low density lipoprotein cholesterol], is often called “bad cholesterol” because it is linked to atherosclerosis, but the landscape is always shifting. Even as cardiologists across the country get used to the new AHA/ACC guidelines, which call for changes in how physicians and patients view LDL-C, new research is focusing attention on other related markers. For example, a recent pair of studies in the New England Journal of Medicine identify gene mutations that lower both triglycerides and heart disease risk, suggesting that drugs that target that gene pathway could be beneficial. A new paper in Atherosclerosis, coauthored by Emory’s Terry Jacobson, looks at LDL-P, a different way of looking at LDL that has been proposed to be a better measure of cardiovascular disease risk. Jacobson is director of the Office of Health Promotion and Disease Prevention at Grady Health Systems. Read more
An intriguing image for November comes from biomedical engineer Mike Davis’ lab, courtesy of BME graduate student Inthirai Somasuntharam.
Each year, thousands of children undergo surgery for congenital heart defects. A child’s heart is more sensitive to injury caused by interrupting blood flow during surgery, and excess reactive oxygen species are a key source of this damage.
Davis and his colleagues are able to shut off reactive oxygen species at the source by targeting the NOX (NADPH oxidase*) enzymes that produce them. This photo, from a 2013 Biomaterials paper, shows green fluorescent nanoparticles carrying small interfering RNA. The RNA precisely shuts down one particular gene encoding a NOX enzyme. Eventually, similar nanoparticles may shield the heart from damage during pediatric heart surgery.
In the paper, Somasuntharam used particles made of a slowly dissolving polymer called polyketals. The particles delivered fragile but potent RNA molecules into macrophages, inflammatory cells that swarm into cardiac tissue after a heart attack. Davis and Georgia Tech colleague Niren Murthy previously harnessed this polymer to deliver drugs that can be toxic to the rest of the body.
The polyketal particles are especially well-suited for delivering a payload to macrophages, since those types of cells (as the name implies) are big eaters. Davis reports his lab has been working on customizing the particles so they can deliver RNA molecules into cardiac muscle cells as well.
*While we’re on the topic of NADPH oxidases, Susan Smith and David Lambeth have been looking for and finding potential drugs that inhibit them.
Diabetes and heart disease often intersect. Emory cardiologist Aloke Finn and his colleagues recently had two papers in the Journal of the American College of Cardiology and in Atherosclerosis describing a possible interaction between the widely used diabetes drug metformin and drug-eluting stents, which are used to to treat coronary artery disease. Anwer Habib, MD is the first author of both papers.
The stent props the once-blocked artery open while the drugs in the stents are supposed to prevent the artery from becoming blocked again. The drugs — usually mTOR inhibitors such as everolimus or the newer zotarolimus — slow down cell growth, but this cuts both ways. The drugs slow down the recovery of the lining of the blood vessel and this may contribute to blood clot formation after stent placement.
In cultured human cells and in rabbits with implanted stents, Finn and colleagues showed that metformin augmented the effect of mTOR inhibitors on regrowth of the blood vessel lining. (However — the authors acknowledge that their animal model was not diabetic or atherosclerotic.)
The findings could mean that people taking metformin would need to take medications to prevent blood clotting medications for a longer time after stent placement. The authors say that clinical studies following patients who receive drug-eluting stents should look at metformin’s effects on blood clotting events. A study examining drug eluting stents in diabetic patients is in the works at Emory.
The stress of public speaking is enough to drive damage-repairing progenitor cells out of the bone marrow into the blood, a study of patients with heart disease has found.
Endothelial progenitor cells (EPCs) are found in the bone marrow, and thought to repair damaged blood vessels once mobilized into the blood by injury or stress. Previous research has shown that strenuous exercise can lead to a dramatic increase in blood EPC levels, but the effects of psychological stress on EPCs had not been examined before.
This report emerges from a large NHLBI-funded study of mental stress ischemia previously described in Emory Public Health magazine.
The new findings were presented Saturday, March 9 at the American College of Cardiology conference in San Francisco. The presenter was cardiovascular research fellow Ronnie Ramadan, MD. Senior authors are Arshed Quyyumi, MD, professor of medicine and director of the Emory Cardiovascular Research Institute, and Viola Vaccarino, MD, PhD, professor and chair of the Department of Epidemiology, Rollins School of Public Health.
In some patients with coronary artery disease, mental stress may precipitate ischemia– a deficiency in blood flow to the heart – a risk factor for adverse events and death independent of other cardiovascular risk factors such as smoking, cholesterol and diabetes.
Approximately 250,000 people each year suffer from a particularly deadly form of heart attack known as a STEMI (ST-Elevation Myocardial Infarction), in which blood flow is completely blocked to the heart. Restoring blood flow quickly is crucial in order to save the patient’s life, yet more than 30 percent of these patients receive no life-saving intervention at all.
Led by Emory emergency medicine physician Michael Ross, the Society of Chest Pain Centers (SCPC) and the American Heart Association (AHA) recently announced they will be joining efforts to save even more lives. The joint agreement seeks to improve cardiac care, specifically the care of patients suffering from STEMI.
The new collaborative framework for hospital accreditation meets criteria of the AHA initiative “Mission: Lifeline,” established in 2007 to improve the processes surrounding care of the STEMI patient by eliminating the obstacles that keep patients from accessing and receiving appropriate treatments.
Mission: Lifeline systems start with the 9-1-1 call or at the point of entry in the emergency system, continue through the catheterization laboratory and through hospital discharge by promoting best practices that use the latest scientific evidence-based treatment for STEMI.
Mission: Lifeline systems currently cover more than 56 percent of the United States. Mortality rates from STEMI have decreased from 5.8 percent in 2008 to 4.8 percent in 2010.
“SCPC, through their Chest Pain Center accreditation, has already improved cardiac processes in close to 14 percent of hospitals within the U.S. and has moved this accreditation to the international setting,” says Ross, who is immediate-past SCPC president and an associate professor of emergency medicine and medical director for observation medicine at Emory.
“Collaboration between these two non-profit organizations, who share similar missions, will help bring consistency to health care delivery by providing a standard approach to the treatment of STEMI. Providing cardiac accreditation programs is in the best interest of patients, meets the needs of the health care community, and will help to significantly reduce cardiac deaths.”
Both Emory University Hospital and Emory University Hospital Midtown are not only accredited by the Society of Chest Pain Centers, but are also the only accredited chest pain centers in metropolitan Atlanta to be accredited with PCI (percutaneous coronary intervention), which indicates a higher level of emergency cardiac care services.
Most commonly known as coronary angioplasty, PCI is a therapeutic procedure to treat the narrowed coronary arteries of the heart found in coronary heart disease. The designation is a distinguishing attribute since PCI is now the preferred treatment for heart attack patients.
For more information about heart disease and cardiac care option – from heart transplants and ventricular assist devices to imaging services and minimally-invasive interventional treatments, please visit Emory Healthcare at: http://www.emoryhealthcare.org/heart-center-atlanta/.
Emory Heart & Vascular Center cardiologist, Khusrow Niazi, MD, will answer questions about peripheral artery disease (PAD) in a live web chat today from 12:30 p.m. to 1:15 p.m. Also called peripheral vascular disease, PAD occurs when arteries in the legs narrow as a result of atherosclerosis, a buildup of fatty deposits and plaque in the lining of blood vessels. When plaque builds up in the blood vessels that carry blood from the heart to the rest of the body, they harden, narrow and clog, causing poor circulation. PAD often goes unrecognized, causing no symptoms at all – or symptoms you may think are something else, such as muscle cramps.
While difficulty walking may be the primary symptom, PAD can advance to complete arterial blockage and critical limb ischemia, causing painful foot ulcers, infections or even gangrene that requires amputation. It is associated with high blood pressure, diabetes, heart disease and stroke and affects eight to 12 million people in the United States.
Dr. Niazi, assistant professor of medicine, Emory University School of Medicine, will be available to answer questions and discuss various topics around PAD, including prevention, detection, healthy tips, rehabilitation and innovative new cardiovascular research on the horizon.
To join the interactive session, please visit the following link to register: http://www.emoryhealthcare.org/heart-center-atlanta/chat-signup-form.html
Since October 2007, Emory University Hospital has been one of approximately 20 hospitals nationwide, and the only site in Georgia, studying a new non-surgical treatment option for patients with failing aortic valves. The life threatening heart condition,aortic stenosis, affects tens of thousands of Americans each year when the aortic valve tightens or narrows, preventing blood from flowing through normally.
As part of the Phase II clinical trial, researchers have been performing transcatheter aortic valve implantation (TAVI) comparing this procedure with traditional, open-heart surgery or medical therapy in high-risk patients with aortic stenosis.
During the TAVI procedure, doctors create a small incision in the groin or chest wall and then feed the new valve, mounted on a wire mesh on a catheter, and place it where the new valve is needed. This offers a non-invasive way for doctors to treat patients who are too ill or frail to endure the traditional open-heart surgical approach.
The study, published Wednesday in The New England Journal of Medicine (NEJM) followed 358 patients who received either catheter-delivered valves or standard non-surgical treatment.
The findings showed that patients who had replacement heart valves delivered by catheter were more likely to survive a year than patients who were treated without replacing their original valves. According to the authors, catheter-delivered valves “should be the new standard of care” for patients who are not able to undergo surgery.
“These results show great promise for patients with severe aortic stenosis and help us make a giant step forward in our battle against this common disease,” says Peter Block, MD, professor of medicine, Emory School of Medicine and principal investigator of the study at Emory. “They are especially important since the number of people with failing valves is expected to greatly increase as baby boomers continue to age.”
Aortic valve stenosis often occurs with age, most commonly among elderly patients over 70 years of age, but can surface earlier in life in those with rheumatic heart disease or congenital abnormalities of the valve.
Approximately 90 patients have received new valves at Emory since the clinical trial started in 2007. Researchers hope to receive FDA approval in late 2011.
A higher level of education is associated with reduced risk of heart disease and stroke for people who live in rich countries, but not for those in low- and middle-income nations, according to the findings of a recent study led by Emory epidemiologist and cardiologist Abhinav Goyal, MD, MHS.
The study published in the Sept. 7, 2010, issue of the journal Circulation, a publication of the American Heart Association, is one of the first international studies to compare the link between formal education and heart disease and stroke. It examined data on 61,332 people from 44 countries who had been diagnosed with heart disease, stroke, or peripheral arterial disease, or who had cardiovascular disease risk factors such as smoking or obesity.
Goyal and team found that highly educated men in high-income countries had the lowest level of cardiovascular disease. However, their findings suggest that research conducted in richer nations can’t always be applied to poorer countries.
“We can’t simply take studies that are conducted in high-income countries, particularly as they relate to socioeconomic status and health outcomes, and extrapolate them to low- and middle-income countries,” says Goyal, assistant professor of epidemiology and cardiology at Emory’s Rollins School of Public Health and Emory School of Medicine. “We need dedicated studies in those settings.”
The research team was surprised to find that despite decreased heart disease risk among the higher educated in industrialized nations, nearly half of the highly educated women from high-income countries smoked, compared with 35 percent for those with the least amount of schooling. For men, smoking rates were virtually the same across educational groups in low- and middle-income countries.
“Everyone needs to be educated about the risk of heart disease in particular, and counseled to adopt healthy lifestyles and to quit smoking,” Goyal says.
Many people know that heart disease is currently the number one killer of women in the United States. But a little more than a half a century ago it was widely believed that cardiovascular disease only affected men. Renowned cardiologist, Nanette K. Wenger, MD, challenged this theory and thanks to her pioneering efforts over the last 50 years women today know better.
Wenger, a professor of medicine in the division of cardiology at Emory University School of Medicine and former chief of cardiology at Grady Memorial Hospital, is being honored as the 2010 Georgia Woman of the Year for her lifetime commitment to reducing women’s disability and death from cardiovascular disease.
She joins the ranks of other distinguished Georgia women including First Lady Rosalynn Carter who was named the first Georgia Woman of the Year in 1996 by the Georgia Commission on Women. In addition to this prestigious accolade, Wenger has accumulated dozens of awards throughout her celebrated career including the Lifetime Achievement Award from the American College of Cardiology in 2009. She is a sought after lecturer for issues related to heart disease in women, heart disease in the elderly, cardiac rehabilitation, coronary prevention and contemporary cardiac care.
The National Institutes of Health (NIH) has convened a key meeting at Emory on women’s cardiovascular health and research. The meeting, co-hosted by the Office of Research on Women’s Health and Emory School of Medicine, is focused today and tomorrow on NIH planning of the women’s health research agenda for the next decade.
Vivian Pinn, MD, associate director for research on women’s health, and director of the Office of Research on Women’s Health at NIH, opened the meeting with Emory’s conference chair, Nanette Wenger, MD, professor of medicine (cardiology), Emory School of Medicine, and chief of cardiology at Grady Memorial Hospital.
In a career that spans more than 50 years, Wenger’s dedication to reducing women’s disability and death from cardiovascular disease has made her one of the country’s most-respected experts on coronary heart disease in women. In 2009, Wenger received the Lifetime Achievement Award from the American College of Cardiology.
Although Wenger has earned dozens of awards in her celebrated career, she says her greatest professional achievement has been to help change a major paradigm in cardiology: the assumption that heart disease affects only men. A half a century ago heart disease was thought of as a “man’s disease.”