Link between flu and heart attack confirmed in new research

Chances of a heart attack are increased six-fold during the first seven days after detection of laboratory-confirmed influenza infection, according to a new study by researchers at the Institute for Clinical Evaluative Sciences (ICES) and Public Health Ontario (PHO).

"Our findings are important because an association between influenza and acute myocardial infarction reinforces the importance of vaccination," says Dr. Jeff Kwong, a scientist at ICES and PHO and lead author of the study.

In the study published in the New England Journal of Medicine, the researchers found a significant association between acute respiratory infections, particularly influenza, and acute myocardial infarction.

The risk may be higher for older adults, patients with influenza B infections, and patients experiencing their first heart attack. The researchers also found elevated risk -- albeit not as high as for influenza -- with infection from other respiratory viruses.

"People at risk of heart disease should take precautions to prevent respiratory infections, and especially influenza, through measures including vaccinations and handwashing," says Kwong.

The researchers add that patients should not delay medical evaluation for heart symptoms particularly within the first week of an acute respiratory infection.

provided by Public Health Ontario..........

Macrophages conduct electricity, help heart to beat

"This work opens up a completely new view on electrophysiology; now, we have a new cell type on the map that is involved in conduction," says senior author Matthias Nahrendorf, a systems biologist at Massachusetts General Hospital, Harvard Medical School. "Macrophages are famous for sensing their environment and changing their phenotype very drastically, so you can think about a situation where there is inflammation in the heart that may alter conduction, and we now need to look at whether these cells are causally involved in conduction abnormalities."

Nahrendorf showed the results to his colleagues, David Milan and Patrick Ellinor, both electrophysiologists at Massachusetts General Hospital, who responded by opening the doors to their labs. Together, the teams found that macrophages extend their cell membranes between cardiac cells and create pores, also called gap junctions, for the electrical current to flow through. The macrophages contribute by preparing the conducting heart cells for the next burst of electricity so conducting cells are able to keep up with a fast contraction rhythm.

The group will follow up by looking at whether macrophages are involved in common conduction abnormalities. There are also potential connections between macrophages and anti-inflammatory drugs, which are widely reported to help with heart disease. If macrophages do play a role in disease, the researchers say it can open up a new line of therapeutics, as these immune cells naturally consume foreign molecules in their presence and are easy to target as a result.

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Revealed by Cell Press.

Cardiac macrophages found to contribute to a currently untreatable type of heart failure

The concept of heart failure traditionally referred to a loss of the organ's pumping capacity, which is called systolic heart failure. But in HFpEF the heart retains the ability to pump or eject blood into the circulation. What is compromised is the ability of the heart muscle to relax and allow blood to flow into the left ventricle, reducing the amount of blood available to pump into the aorta. Symptoms of HFpEF are similar to those of heart failure in general, but since factors contributing to the condition are not well understood, it has been difficult to find promising therapies.

Interactions among cells within the heart -- including macrophages -- are essential to normal cardiac function but can also contribute to problems. For example, after the heart muscle is damaged by a heart attack, macrophages induce the cells called fibroblasts to generate the connective tissues that help reinforce damaged tissue. But excessive fibroblast activation can lead to the distortion and stiffening of tissues, further reducing cardiac function.

"Not only were numbers of inflammatory cardiac macrophages increased in both the mice and in humans with HFpEF, but their characteristics and functions were also different from those in a healthy heart," says Hulsmans. "Through their participation in the remodeling of heart tissue, these macrophages increase the production of extracellular matrix, which reduces diastolic relaxation. Our findings regarding the cell-specific knockout of IL-10 are the first to support the contribution of macrophages to HFpEF."

Senior author Mathias Nahrendorf, MD, PhD , of the Center for Systems Biology, adds, "Heart muscle cells and fibroblasts have been considered the major contributors to HFpEF. Our identification of the central involvement of macrophages should give us a new focus for drug development. And since macrophages naturally take up materials for disposal, inducing them to ingest drugs carried in by nanoparticles could limit their contributions to the development of HFpEF." Nahrendorf is a professor of Radiology at Harvard Medical School.

Revealed by  Massachusetts General Hospital.

Red wine proves good for the heart (again).........

Antioxidants found in wine have advanced stents

Antioxidant compounds found in red wine are advancing the treatment of heart disease -- the leading cause of death for both men and women in the U.S.

Heart disease occurs when plaque builds up within artery walls blocking the blood flow through tissues in the body, increasing the risk of a heart attack or stroke. About 630,000 people die each year from heart disease, according to the Centers for Disease Control and Prevention.

While there is no singular cure for heart disease, there are numerous forms of treatment including lifestyle changes and surgical procedures. In one procedure called a coronary angioplasty, a surgeon inserts and inflates a tiny balloon inside a blocked or narrow artery to widen it and allow blood to flow through to the heart thereby decreasing the risk of a heart attack or stroke. This procedure often includes inserting a permanent small mesh tube to support the blood vessel called a stent.

Commercial stents can release chemotherapy agents that are toxic and can cause the blood vessel to narrow again. LSU Department of Comparative Biomedical Sciences Professor Tammy Dugas is developing a new stent that releases red wine antioxidants slowly over time that promotes healing and prevents blood clotting and inflammation. The two antioxidant compounds are resveratrol and quercetin.

"By delivering red wine antioxidants during conventional angioplasty, it may be possible to prevent excess tissue from building up and the blood vessel from narrowing again as it heals," Dr. Dugas said.

In addition to the stent, Dugas and colleagues are developing a balloon coated with the same compounds to treat blood flow blockages throughout the body called peripheral artery disease. This disease which can limit the blood flow to kidneys, the stomach, arms or legs affects about 8 to 12 million Americans. However, less than 20 percent are diagnosed by a physician. Drug-coated balloons are a relatively new product, and are being developed to help interventional cardiologists treat arteries that are difficult to target with traditional angioplasty and stent treatments.
Revealed by Louisiana State University......