Tag: heart attack

Categories : Cardiovascular Disease Lab Tests and ImagingTags :

New Blood Test on a Chip Rapidly Detects Earliest Signs of Heart Attack

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Peng Zheng shows off the heart of the blood test, chip with a groundbreaking nanostructured surface on which blood is tested. Image: Will Kirk / Johns Hopkins University

With heart attacks, every second counts. A newly developed blood test on a chip diagnoses them in minutes rather than hours and could be adapted as a tool for first responders and people at home.

“Heart attacks require immediate medical intervention in order to improve patient outcomes, but while early diagnosis is critical, it can also be very challenging – and near impossible outside of a clinical setting,” said lead author Peng Zheng, an assistant research scientist at Johns Hopkins University. “We were able to invent a new technology that can quickly and accurately establish if someone is having a heart attack.”

The proof-of-concept work, which can be modified to detect infectious diseases and cancer biomarkers, is described in Advanced Science.

Zheng and senior author Ishan Barman develop diagnostic tools through biophotonics, using laser light to detect biomarkers, which are bodily responses to conditions including disease. Here they used the technology to find the earliest signs in the blood that someone was having a heart attack. Heart attacks remain one of the trickiest conditions to diagnose, with symptoms that vary widely and biological signals that can be subtle and easy to miss in the early stages of an attack, when medical intervention can do the most good.

Will be like ‘ Star Trek tricorder’

People suspected of having heart attacks typically are given a combination of tests to confirm the diagnosis – usually starting with electrocardiograms to measure the electrical activity of the heart, a procedure that takes about five minutes, and blood tests to detect the hallmarks of a heart attack, where lab work can take at least an hour and often has to be repeated.

The stand-alone blood test the team created provides results in five to seven minutes. It’s also more accurate and more affordable than current methods, the researchers say.

Though created for speedy diagnostic work in a clinical setting, the test could be adapted as a hand-held tool that first responders could use in the field, or that people might even be able to use themselves at home.

“We’re talking about speed, we’re talking about accuracy, and we’re talking of the ability to perform measurements outside of a hospital,” said Barman, a bioengineer in JHU’s Department of Mechanical Engineering. “In the future we hope this could be made into a hand-held instrument like a Star Trek tricorder, where you have a drop of blood and then, voilà, in a few seconds you have detection.”

The heart of the invention is a tiny chip with a groundbreaking nanostructured surface on which blood is tested. The chip’s “metasurface” enhances electric and magnetic signals during Raman spectroscopy analysis, making heart attack biomarkers visible in seconds, even in ultra-low concentrations. The tool is sensitive enough to flag heart attack biomarkers that might not be detected at all with current tests, or not detected until much later in an attack.

Though designed to diagnose heart attacks, the tool could be adapted to detect cancer and infectious diseases, the researchers say.

“There is enormous commercial potential,” Barman said. “There’s nothing that limits this platform technology.”

Next the team plans to refine the blood test and explore larger clinical trials.

Source: John Hopkins University

Categories : Cardiovascular Disease Neurodegenerative DiseasesTags :

Heart Attack Survivors at Lower Risk of Parkinson’s

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Credit: American Heart Association

Heart attack survivors may be slightly less likely to develop Parkinson’s disease later in life, according to new research published in the Journal of the American Heart Association.

Parkinson’s disease (PD) is a common neurodegenerative disorder. While a number of non-motor manifestations arise, the typical clinical features involve a movement disorder consisting of bradykinesia, resting tremor, and rigidity, with postural instability occurring at a later stage. The cause of PD is not known, but a number of genetic risk factors have now been characterised, as well as several genes which cause rare familial forms of PD. Secondary parkinsonism, which has symptoms similar to Parkinson’s disease, may be caused by stroke, psychiatric or cardiovascular medications, or other illness.

“We have previously found that following a heart attack, the risk of neurovascular complications such as ischaemic stroke or vascular dementia is markedly increased, so the finding of a lower risk of Parkinson’s disease was somewhat surprising,” said lead study author Jens Sundbøll, MD, PhD. “These findings indicate that the risk of Parkinson’s disease is at least not increased following a heart attack and should not be a worry for patients or a preventive focus for clinicians at follow-up.

“It is not known whether this inverse relationship with risk of Parkinson’s disease extends to people who have had a heart attack. Therefore, we examined the long-term risk of Parkinson’s disease and secondary parkinsonism among heart attack survivors,” Dr Sundbøll said.

Drawing on Danish National Health Service data, the researchers compared the risk of PD and secondary parkinsonism among roughly 182 000 patients who had a first-time heart attack between 1995 and 2016 (average age 71 years old; 62% male) and more than 909 000 matched controls. 

Over a maximum continual follow-up of 21 years, after adjusting for a wide range of potential confounding factors, the analysis found that, when compared to the control group:

  • there was a 20% lower risk of PD among people who had a heart attack; and
  • a 28% lower risk of secondary parkinsonism among those who had a heart attack.

“For physicians treating patients following a heart attack, these results indicate that cardiac rehabilitation should be focused on preventing ischaemic stroke, vascular dementia and other cardiovascular diseases such as a new heart attack and heart failure, since the risk of Parkinson’s appears to be decreased in these patients, in comparison to the general population,” Dr Sundbøll said.

Certain risk factors are common to both heart attack and PD, with higher risk found among elderly men and lower risk among people who drink more coffee and are more physically active. Interestingly, however, some classic heart attack risk factors – such as smoking, high cholesterol, hypertension and Type 2 diabetes – are associated with a reduced risk of PD.

In general, more heart attack patients smoke and have high cholesterol, either of which may explain the slightly reduced risk of PD among heart attack survivors.

“There are very few diseases in this world in which smoking decreases risk: Parkinson’s disease is one, and ulcerative colitis is another. Smoking increases the risk of the most common diseases including cancer, cardiovascular disease and pulmonary disease and is definitely not good for your health,” Dr Sundbøll noted.

One limitation of the study is that there was not enough information about smoking and high cholesterol levels among the participants, which may have influenced the findings. The study participants were almost entirely white, limiting the generalisability to other ethnic groups.

Source: American Heart Association

Categories : Cardiovascular DiseaseTags :

Eight Factors Predict Gastrointestinal Bleeding Risk after Heart Attack

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Using machine learning, researchers at Karolinska Institutet have identified eight primary factors that increase the risk of a common bleeding complication after heart attack.

Some of these factors had been known already, however, the researchers have found additional predictors, such as smoking, blood pressure and blood glucose. The study was published in the European Heart Journal – Cardiovascular Pharmacotherapy.

“If we can identify patients at high risk of upper gastrointestinal bleeding following heart attack, doctors will be able to take prophylactic measures to mitigate this risk,” said the study’s corresponding author Moa Simonsson, deputy consultant at Karolinska University Hospital and doctoral student. “There are, for instance, drugs that combat bleeding complications, gut bacteria tests that can be used on risk groups and other possibilities for personalised treatment for heart attack patients at high risk of bleeding complications.”

Upper gastrointestinal (GI) tract bleeding is one of the most common bleeding complications following acute myocardial infarction. The condition requires a lot of resources to treat, causes considerable suffering and increases mortality risk. Bleeding complications also limit antithrombotic use, which in turn can worsen the cardiovascular prognosis.

Over the past 20 years, a close focus on bleeding has resulted in several strategies for reducing the risk of upper gastrointestinal tract bleeding. However, few studies on this complication include a diverse population of heart attack patients.

For the current study, the researchers sourced data from the national SWEDEHEART registry on almost 150 000 patients with acute myocardial infarction between 2007 and 2016. Approximately 1.5 percent of these patients suffered GI bleeding within a year of their heart attack, and they also had an increased risk of death and stroke.
Several known factors that increase the risk of upper GI tract bleeding were confirmed by the analysis, including low levels of haemoglobin, previous upper GI tract bleeding, age and intensive antithrombotic treatment.

Using an algorithm, the researchers also identified additional risk factors, including smoking, blood pressure, blood glucose and previous treatment for stomach disorders, such as ulcers and acid reflux.

“If you combine traditional statistical models with machine learning methods, you can create unique opportunities to find key risk factors for previously unknown cardiovascular events,” explained co-author Philip Sarajlic, doctoral student at Karolinska Institutet. “This makes it possible for us to make effective use of valuable data from the medical quality registry by taking account of complex relationships between risk factors and outcomes in order to further optimise the current recommendations for patient care.”

The researchers will soon begin a major clinical study to explore the significance of diagnosis and treatment of a common infection in the upper GI tract.

“A pilot study last year showed a two-fold increase in the presence of Helicobacter Pylori in heart attack patients,” said last author Robin Hofmann, researcher and consultant at Karolinska Institutet. “We will now proceed with a large randomized study to ascertain whether a systematic screening of heart attack patients for Hp infection and, where relevant, its treatment, can reduce bleeding complications and improve prognosis after heart attack.”

Source: Karolinska Institute