How stress may increase risk of heart disease

Heightened activity in the amygdala -- a region of the brain involved in stress -- is associated with a greater risk of heart disease and stroke, according to a study published in The Lancet that provides new insights into the possible mechanism by which stress can lead to cardiovascular disease in humans.

While more research and larger studies are needed to confirm the mechanism, the researchers suggest that these findings could eventually lead to new ways to target and treat stress-related cardiovascular risk.

Smoking, high blood pressure and diabetes are well-known risk factors for cardiovascular disease and chronic psychosocial stress could also be a risk factor.

Previously, animal studies identified a link between stress and higher activity in the bone marrow and arteries, but it has remained unclear whether this also applies to humans. Other research has also shown that the amygdala is more active in people with post-traumatic stress disorder (PTSD), anxiety and depression, but before this study no research had identified the region of the brain that links stress to the risk of heart attack and stroke.

In this study, 293 patients were given a combined PET/CT scan to record their brain, bone marrow and spleen activity and inflammation of their arteries. The patients were then tracked for an average of 3.7 years to see if they developed cardiovascular disease. In this time 22 patients had cardiovascular events including heart attack, angina, heart failure, stroke and peripheral arterial disease.

Those with higher amygdala activity had a greater risk of subsequent cardiovascular disease and developed problems sooner than those with lower activity.

The researchers also found that the heightened activity in the amygdala was linked to increased bone marrow activity and inflammation in the arteries, and suggest that this may cause the increased cardiovascular risk. The authors suggest a possible biological mechanism, whereby the amygdala signals to the bone marrow to produce extra white blood cells, which in turn act on the arteries causing them to develop plaques and become inflamed, which can cause heart attack and stroke.

In a small sub-study, 13 patients who had a history of PTSD also had their stress levels assessed by a psychologist, underwent a PET scan and had their levels of C-reactive protein -- a protein that indicates levels of inflammation in the body -- measured. Those who reported the highest levels of stress had the highest levels of amygdala activity along with more signs of inflammation in their blood and the walls of their arteries.

"Our results provide a unique insight into how stress may lead to cardiovascular disease. This raises the possibility that reducing stress could produce benefits that extend beyond an improved sense of psychological wellbeing," said lead author Dr Ahmed Tawakol, Massachusetts General Hospital and Harvard Medical School, USA. "Eventually, chronic stress could be treated as an important risk factor for cardiovascular disease, which is routinely screened for and effectively managed like other major cardiovascular disease risk factors."

The researchers note that the activity seen in the amygdala may contribute to heart disease through additional mechanisms, since the extra white blood cell production and inflammation in the arteries do not account for the full link. They also say that more research is needed to confirm that stress causes this chain of events as the study was relatively small.

Writing in a linked Comment, Dr Ilze Bot, Leiden Academic Centre for Drug Research, Leiden University, The Netherlands, said: "In the past decade, more and more individuals experience psychosocial stress on a daily basis. Heavy workloads, job insecurity, or living in poverty are circumstances that can result in chronically increased stress, which in turn can lead to chronic psychological disorders such as depression." She says that more research is needed to confirm the mechanism but concludes: "These clinical data establish a connection between stress and cardiovascular disease, thus identifying chronic stress as a true risk factor for acute cardiovascular syndromes, which could, given the increasing number of individuals with chronic stress, be included in risk assessments of cardiovascular disease in daily clinical practice."

Story Source: The Lancet. 

Potential RNA Markers of abnormal heart rhythms identified in circulating blood

Atrial fibrillation (AF) is a heart condition that causes an irregular, and often rapid, heart rate. It increases the risk of developing strokes, heart failure, and even dementia. Although it can be associated with aging, high blood pressure, diabetes, heart valve problems, etc, about one-third of patients with AF have no symptoms until they suffer a stroke. Therefore, a means of identifying or predicting AF with the aim of starting preventative therapy is highly desirable.

AF is associated with several factors that maintain its progression, including inflammation, electrical disturbances, and structural changes in the heart's upper chambers (the atria). Moreover, several different short sequences of RNA known as microRNAs (miRNAs) have been linked with AF pathology. miRNAs control gene expression after the transcription stage, and have been suggested as possible markers for some cardiovascular diseases because of their stability in the bloodstream. However, it remains unknown whether the miRNAs shown to be related to AF are suitable as predictive biomarkers of disease.

A team of researchers from Tokyo Medical and Dental University (TMDU) addressed this issue by comparing miRNA expression in AF patients and healthy controls, and between control mice and those with a similar abnormal heart rhythm to AF. They showed that four miRNAs not previously associated with AF were significantly upregulated in the serum of AF patients and diseased mice, indicating their potential use as AF biomarkers. The study results were recently published in Circulation Journal.

Initially, human serum and mouse atrial tissue were screened for 733 and 672 miRNAs, respectively. These were eventually narrowed down to four by excluding non-detectable and non-specific miRNAs, and focusing on the quantification of their expression.

"One of the miRNAs, miR-214-3p, is implicated in inflammation, so we wondered whether this might be the underlying mechanism of miRNA-induced AF pathology," first author Yu Natsume says. "We compared miRNA expression with levels of a serum inflammatory factor but found no correlation suggestive of an association."

Statistical analysis of diagnostic ability showed that miR-214-3p and miR-342-5p had the highest accuracy as individual biomarkers at predicting AF, but that a combined analysis of all four miRNAs slightly improved this accuracy.

"The same two miRNAs showed increased expression in a subset of patients with intermittent AF and another subset with chronic AF," corresponding author Tetsuo Sasano says. "The increases were in comparison both with healthy controls of the same age and young healthy controls, suggesting these miRNAs may predict AF regardless of the age of the individual."

The researchers propose additional studies to determine the functional role of the identified miRNAs with respect to AF.

---

Story Source:Tokyo Medical and Dental University. 

Can Aspirin Lower Your Risk for Heart Attack and Stroke?

How Does Aspirin Prevent a Heart Attack or Stroke?

Aspirin may help lower your risk for a heart attack or stroke by preventing dangerous blood clots from forming. When you damage a blood vessel, usually by a cut or bruise, your body sends small cell fragments called platelets to the site of the injury. The platelets stick together, or clot, to stop the bleeding allow the injury to heal.

Plaque buildup in your arteries can put you at risk for dangerous blood clots because plaque can rupture. If a blood clot forms at the site of the rupture, it can block blood flow and lead to a heart attack or stroke.

Aspirin can help keep platelets from sticking together, thus lowering your risk for dangerous blood clots.

Who Should Take Aspirin for Heart Attack and Stroke Prevention?

Your doctor may recommend daily aspirin to lower your risk for heart attack and stroke if you have:

• Had a heart attack or stroke in the past, or are at risk for one
• Undergone angioplasty or coronary artery bypass surgery
• Peripheral artery disease, or blocked blood vessels in your legs
• Atrial fibrillation, a heart rhythm problem that raises your risk for blood clots
• Coronary artery disease, or blocked blood vessels in your heart

You should only take aspirin for heart health if your doctor recommends it. Your doctor may also suggest taking aspirin with other medicines that can help prevent dangerous blood clots.

If you have a high risk for bleeding or are allergic to aspirin, you shouldn’t take it. Because aspirin affects your blood’s ability to clot, you might bleed easier. It’s important to alert your doctor, dentist, and other health care providers that you’re taking aspirin before undergoing any medical procedures.

Will I Need to Make Other Lifestyle Changes?

In addition to taking aspirin to lower your risk for heart attack and stroke, your doctor might recommend the following lifestyle changes:

• Eat heart-healthy foods, like salmon, berries, and leafy greens
• Quit or avoid smoking
• Get regular physical activity
• Control your blood pressure
• Maintain a healthy weight
• Take your medicines as prescribed

BUT DO NOT TAKE ASPIRIN IN REGULAR OR FREQUENT USE....

By Heart and Vascular Institute...

BLOOD PRESSURE AND HEART RATE

Blood Pressure vs. Heart Rate

Blood pressure

Blood pressure is a two-part measurement, expressed in a fraction, like 120/80 mm Hg.

The first number is the systolic pressure, which measures pressure against your artery walls when your heart contracts and pumps blood out. The second number, called the diastolic pressure, measures the blood’s pressure against the artery wall as your heart rests between pumps.

Hypertension, or high blood pressure, means your heart is working too hard which can weaken your heart and damage your blood vessels. If your blood vessels can’t move blood through your body effectively, your heart and other important organs such as the eyes, brain, and kidneys may not get the oxygen and nutrients they need. High blood pressure raises your risk of heart, disease, heart attack, heart failure, stroke, and kidney disease.

Hypotension, or low blood pressure, means your heart pumps more slowly than normal. That’s not always a problem — athletes sometimes have low blood pressure. However, hypotension can cause symptoms like fatigue, dizziness, weakness, and blurry vision.

Heart rate

A high heart rate or pulse, on the other hand, can indicate stress, excess weight, medicine usage, a poor fitness level, or body position. Your heart rate is the number of times your heart beats per minute, and it can change gradually as you age. The difference between pulse and blood pressure is both in what they measure and what they affect.

How Blood Pressure and Heart Rate Are Related

Interestingly, your heart rate and blood pressure won’t always rise and fall in sync. Even if they both rise, it doesn’t mean they’ll rise at the same rate. When exercising, your heart rate will increase, but your blood pressure may stay the same or increase to a lesser extent. That’s because the blood vessels increase in size to allow for faster and easier flow. The blood flow may not impact the blood pressure reading to the same degree as it does your heart rate.

By UPMC health care......

TOMATOES AND HEART HEALTH

Tomatoes have two key nutrients that have a big impact on heart health: lycopene and potassium.

Lycopene is a chemical that gives a tomato its red color and is also a powerful antioxidant, a type of substance that helps keep cells from becoming damaged. Some research shows that lycopene may lower LDL, or “bad” cholesterol, and keep blood from clotting, which lowers stroke risk.

Potassium is a mineral that can help lower blood pressure by taking some of the sodium out of your body, and by relaxing the walls of your blood vessels.