By Dr Aishah Mohd Hafiz , senior lecturer in emergency medicine, School of Medicine, Faculty of Health and Medical Sciences, Taylor’s University.

As we seek to address SCA awareness and prevention in athletes, we should start raising these questions: How prepared are we to save a life?

Sudden heart disruption

The recent tragic death of a young badminton player brings about several mind-lingering questions. How can a seemingly healthy young athlete, at the peak of his physical fitness, suddenly collapse, resulting in death? Secondly, was it at all preventable?

Sudden Cardiac Arrest (SCA) among athletes is fairly uncommon. However, SCA is the leading medical cause of death among athletes during physical activity, affecting the male gender more than their female counterparts by ten-fold.
Contrary to general belief, SCA does not equate to a heart attack, though it may be a consequence of one.

Related: Breaking the silence on silent heart attacks

Essentially, SCA happens when there is a sudden disruption of the heart’s normal electrical conduction activity, resulting in the heart to either stop abruptly or beat abnormally (ventricular fibrillation or ventricular tachycardia). In both instances, the heart fails to function as a pump, denying the vital organs from receiving a continuous blood flow rich with oxygen and nutrients. If normal rhythm of the heart is not promptly restored, this can lead to death.

In the majority of cases, the cause of SCA during sport activity is due to structural and electrical changes in the heart, which can be either congenital or acquired.

Related: Police working in stressful situations have higher risk of getting cardiac arrest

A recent UK study found the leading cause of SCA in athletes is unknown, possibly due to molecular-level cardiac anomalies that aren’t physically apparent but can trigger arrhythmias. This raises questions about genetic predisposition and the need for genetic screening.

Screening for SCA risks

Although the likelihood of SCA occurring during a sporting event is rare, the aftermath is devastating, nevertheless.
Preventative measures through advocation of pre-participation health screening is essential to identify, especially young athletes at risk. While this is common practice prior to major events such as the Olympics, smaller competitions such as at school or intervarsity levels may not enforce this.

In addition, screening is not a pre-requisite for participation in endurance sporting events that are open to the public, such as marathons and long-distance cycling races. Instead, participants are only mandated to sign a waiver form, releasing the organisers from any responsibilities in the event of SCA. In such instances, it is up to the individual athletes, parents, teachers and the sport team members to take on necessary screening measures.

The American Heart Association (AHA) recommends a targeted medical history and a focused cardiovascular physical examination as sufficient initial steps to identify high risk patients.

This includes seeking for symptoms such as:

1. Shortness of breath,
2. Chest pain
3. Fainting spells or episodes of transient loss of consciousness
4. Notable decline in physical performance

Specific inquiries regarding sudden deaths within the family, relatives with known inherited cardiac conditions, as well as family members with pacemakers or defibrillators in place, should be made.

Further tests in the form of electrocardiograph (ECG) and echocardiogram can be done in the identified athletes. The ECG looks at the electrical activity of the heart andcan display any abnormal rhythms, while the latter looks for any structural abnormalities and the function of the heart. By this stage, consultation with a cardiologist is greatly advised for their expert opinion.

Among athletes aged 35 years and above, coronary artery disease stands out as the most frequent cause of sudden cardiac death. In older athletes, further screening questions should include pre-existing risk factors for a heart attack, such as a strong family history, actively smoking, and chronic illnesses such as diabetes and hypertension.

These characteristics, when present poses additional risks for SCA, thus should be addressed before continuing with any vigorous sporting activities.

Life saving measures with CPR, technologies

Certain individuals may still develop SCA despite receiving the clean bill of health. Pre-participation screening is useful in detecting certain inherited conditions, however as discussed, for some the cause of SCA remains unknown.
Other aggravating factors such as extreme heat or dehydrationduring the day of event may unmask an underlying condition, whichmay not be detected during screening.

In the event where SCA occurs, then all efforts should be made to improve survival outcomes and prevent death.
The effectiveness of CPR and early defibrillation using an automated external defibrillator (AED) for the treatment of SCA is proven and well-established. Essentially, chest compressions mimic the pumping action of the heart, providing the vital organs with any remaining oxygen in the blood.

In certain situations, this may be sufficient to restart the heart. The attempts to provide continuous blood flow minimize permanent injury to the vital organs, improving the outcome if and when normal circulation is restored.
An AED on the other hand, isan easy-to-use device that can quickly detect any life-threatening arrythmias andcan promptly deliver an electrical shock to terminate the abnormal rhythm when needed.
The key factor for successful resuscitation with favourable outcome is early CPR initiation and defibrillation, which ultimately requires rapid recognition of the signs of SCA.

Therefore, it is of upmost importance that the general public have heightened awareness of SCA and possess these basic lifesaving skills, so that treatment can be initiated by anyone even before medical assistance arrives.
In addition, it is the responsibility of the sporting event organisers to ensure the AED devices are readily available and accessible, strategically placed within the compounds of the event. An Emergency Response Plan should also be formulated prior to the event, which includes appointing a highly trained and certified medical standby team.

Even though athletes are the epitome of peak physical health, SCA can still occur within this population due to several reasons. Pre-participation screening is beneficial to detect certain inherited conditions especially among the younger age group, and those at risk of developing a heart attack. On many occasions, however, SCA cannot be prevented. What can be done is to shorten the duration of cardiac arrest and attempt to restore the normal function of the heart as quickly as possible through basic lifesaving skills.

The biomaterial reduces tissue inflammation while also encouraging cell and tissue repair. Researchers from the University of California, San Diego demonstrated in a rodent model that the biomaterial could benefit patients suffering from traumatic brain injury and pulmonary arterial hypertension.

The biomaterial enables treating damaged tissue from the inside out, according to Karen Christman, a professor of bioengineering at the University of California San Diego and the team’s lead researcher.

Within one to two years, a study on the biomaterial’s safety and effectiveness in human subjects could begin, added Christman. The team, which consists of bioengineers and doctors, presented its findings in the December 2022 issue of Nature Biomedical Engineering.

According to the researchers, there has yet to be an established treatment for repairing the resulting damage to cardiac tissue. Scar tissue forms after a heart attack, which reduces muscle function and can lead to congestive heart failure.

Previously, Christman’s team created a hydrogel made from the natural scaffolding of cardiac muscle tissue, also known as the extracellular matrix (ECM), that can be injected into damaged heart muscle tissue via a catheter. In damaged areas of the heart, the gel forms a scaffold, encouraging new cell growth and repair.

The results of a successful phase 1 human clinical trial were announced. However, because it must be injected directly into the heart muscle, it can only be used a week or more after a heart attack; using it sooner risked causing damage due to the needle-based injection procedure.

The team aimed to create a treatment that could be given immediately following a heart attack. This meant creating a biomaterial that could be injected intravenously or infused into a blood vessel in the heart alongside other treatments such as angioplasty or a stent.

Because the new biomaterial is infused or injected intravenously, it is evenly distributed throughout damaged tissue. In contrast, hydrogel injected through a catheter remains concentrated and does not spread.

The new biomaterial was tested on a rodent model of a heart attack. They expected the material to pass through the blood vessels and into the tissue because gaps form between endothelial cells in blood vessels after a heart attack. The biomaterial, on the other hand, binds to those cells, closing the gaps and accelerating blood vessel healing, reducing inflammation. The biomaterial was also tested in a porcine model of heart attack, yielding similar results.

Christman and a startup she cofounded, Ventrix Bio, Inc, will seek FDA approval to conduct a human study of the new biomaterial’s applications for heart conditions. This means that human clinical trials will begin within the next year or two. Meanwhile, Martin Spang, the paper’s first author, believes that the ability to treat other difficult-to-reach organs and tissues will broaden the field of biomaterials/tissue engineering into the treatment of new diseases.

Source: UC San Diego- https://today.ucsd.edu/story/this-groundbreaking-biomaterial-heals-tissues-from-the-inside-out

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Researchers at the Duke-NUS Medical School in Singapore have discovered that people living in tropical climates, which have narrow temperature ranges, are at increased risk of a heart attack – more specifically, a type of acute myocardial infarction.

It was also revealed that people aged 65 and above were about 20% more vulnerable to cooler temperatures compared to younger people, based on a 10-year national study of Singaporeans, said Professor Marcus Ong, Director of the Health Services & Systems Research Programme and the Pre-hospital & Emergency Research Centre (PERC) at Duke-NUS Medical School and Senior Consultant at the Department of Emergency Medicine at Singapore General Hospital (SGH).

The researchers had pulled and analysed data from the Singapore Myocardial Infarction Registry’s daily patient records, specifically looking for those who experienced a type of acute heart attack that happens when a blood vessel feeding the heart becomes partially blocked (non-ST-segment elevation myocardial infarction, or NSTEMI).

The onset of NSTEMI in these patients was cross-referenced with local meteorological data obtained from the National Environment Agency’s (NEA) weather stations across Singapore. The data included mean temperatures and rainfall.

According to over 60,000 NSTEMI reports, cooler ambient temperatures were independently associated with an increased risk of NSTEMI up to 10 days after a temperature drop. However, there were no gender differences relating to the effects of warmer or cooler temperatures on NSTEMI risk, nor were changes in rainfall associated with an increased risk of NSTEMI.

“There are several individual-level risk factors for cardiovascular disease, but none are as widely experienced as weather patterns,” supplied Dr. Joel Aik, an Environmental Epidemiologist and Adjunct Assistant Professor with PERC. “Daily weather variations have the capacity to trigger cardiovascular disease events in at-risk individuals, with particular implications for Singapore’s ageing population. In the context of climate change, these findings highlight a risk factor of substantial public health concern.”

The researchers are looking into identifying the biological pathways involved in increased vulnerability of the elderly to cold-related NSTEMI in the tropics.

Recreational marijuana users who smoke more than once a month have an increased risk of heart attack and heart disease. According to new research from Stanford University, the psychoactive component of marijuana, tetrahydrocannabinol (THC), caused inflammation in endothelial cells that line the inside of blood vessels, as well as atherosclerosis, in studied mice.

It was later discovered that the inflammation could be blocked by a soybean-derived molecule called genistein, without changing THC’s pain-alleviating or sedating effects — characteristics vital to medicinal marijuana users.

A significant proportion of 500,000 study subjects who smoked marijuana more than once a month were found to be much more likely to have a heart attack before the age of 50 compared to non-users. The researchers showed that THC promotes inflammation and atherosclerosis in human endothelial cells grown in the laboratory. Similarly, mice bred to have high cholesterol levels and fed a high-fat diet developed significantly large atherosclerosis plaques when injected with THC at levels comparable to smoking one marijuana cigarette per day.

[While THC typically binds to a receptor called CB1 on cells in the human brain, heart, and vasculature, which regulate mood, pain perception, immune function and metabolism, frequent marijuana use causes inappropriate activation of CB1, which in turn causes inflammation and atherosclerosis. Inappropriate activation of CB1 is also associated with obesity, diabetes, and cancer.]

Further screening revealed a molecule capable of blocking the pro-inflammatory effects of THC whilst maintaining its psychoactive effects on the brain – genistein. Found in soybeans and fava beans, genistein does not cross the blood-brain barrier: in mouse studies, genistein reduced endothelial dysfunction in THC-treated mice without disrupting the drug’s effects on the animal’s central nervous system.

“Our studies of human cells and mice clearly outline how THC exposure initiates a damaging molecular cascade in the blood vessels,” said Stanford’s Dr. Mark Chandy. “[Genistein] is already used as a nutritional supplement, and 99% of it stays outside the brain, so it shouldn’t cause these particular adverse side effects.”

However, the researchers admit a more thorough clinical trial is needed to explore the greater effects of genistein on marijuana users and cardiovascular risk. The researchers also call for medical marijuana users to be aware of potential cardiovascular risks from using the drug.

Read: Higher risk of heart disease for people with cognitive impairment

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A heart attack is caused by buildup of plaque along the walls of the arteries of the heart, causing it to narrow and the cardiac muscle to overwork to pump blood. There is a diagnostic test available called a coronary computed tomography angiography (CTA) that takes 3D images of the heart and arteries, however, it its not automated nor simple to produce results.

Bearing that in mind, medical scientists from Cedars-Sinai Medical Center have developed an artificial intelligence (AI)-based tool to predict a person’s likelihood of having a heart attack by measuring visible plaque from CTA images. The AI algorithm was built from CTA images that were already analysed by trained doctors: it first outlines the coronary arteries in 3D images, then identifies blood and plaque deposits within the coronary arteries.

Dr. Damini Dey, Professor of Biomedical Sciences and Director of the quantitative image analysis lab in the Biomedical Imaging Research Institute at Cedars-Sinai, and colleagues compared CTA images from the AI algorithm to another set of CTA images from almost 1,200 people from five different countries including Japan and Scotland.

The tool’s measurements were found to correspond with plaque amounts seen in coronary CTAs. They also matched results with images taken by two invasive tests – intravascular ultrasound and catheter-based coronary angiography – considered to be highly accurate in assessing coronary artery plaque and narrowing.

In addition, measurements made by the AI algorithm from CTA images accurately predicted heart attack risk within five years for 1,611 people who were part of the SCOT-HEART (Scottish Computed Tomography of the HEART) trial.

“[…] now we can use this program to quantify plaque from CTA images in five to six seconds,” said Dr. Dey. “More studies are needed, but it’s possible we may be able to predict if and how soon a person is likely to have a heart attack based on the amount and composition of the plaque imaged with this standard test.”

Read: Higher risk of heart failure and stroke even after COVID-19 recovery

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Heart muscle becomes damaged and cardiac function is affected when blood vessels feeding the heart are blocked. A new stem-cell-carrying hydrogel helps mice recover from this condition, called myocardial infarction, by stimulating formation of new blood vessels. Developed by a team of scientists at Kansai University in Japan, the stem cell delivery system is described in the journal Science and Technology of Advanced Materials.

The hydrogel acts as a scaffold that holds the stem cells in place at the site of injection and keeps them alive for longer. The stem cells produce cytokines that stimulate the formation of blood vessels to help the heart recover. The gel is biodegradable, so it eventually dissolves and is removed by the body.

Read also: Participation from partners helps heart attack survivors stick to healthy, new habits

The team used stem cells derived from fat tissue in their application. These so-called ‘adipose-derived stem cells’ have already been investigated for treating damaged cardiac tissue from reduced blood flow to the heart, known as myocardial ischemia. The idea is that the stem cells will release stimulating factors to regenerate blood vessels once injected into damaged heart tissue. The problem, though, is that they can’t be retained or survive in the tissue long enough. In other studies, scientists have found that injecting cell-free biodegradable hydrogels into damaged heart tissue helps partial recovery of heart functions.

Kansai University bioengineer Yuichi Ohya and his colleagues mixed the two techniques together.

Firstly, they developed hydrogel formulas that can hold stem cells in place for longer periods of time at the site of tissue damage. These hydrogels start off as a solution when they are at room temperature. This makes it easy to mix in the stem cells. When the solution is injected into an organ, it warms to body temperature, triggering its transformation into a gel.

One of their hydrogels was especially good at staying in its gel state. It was made with a combination of molecules, called tri-PCG, with acrolyl groups attached to them. The tri-PCG-acryl was then mixed with a polythiol derivative.

The team added adipose-derived stem cells to the hydrogel and observed, both in petri dishes and inside mouse heart tissue, how long the cells lived and what kinds of genes and substances were produced by the cells.

“The stem cells were able to survive in our injectable hydrogel and released molecules that stimulate blood vessel formation, improving heart function and making it effective for treatment of ischemic heart,” says Ohya.

The team next plans to test their therapy on larger animals after confirming its safety, and then to conduct clinical studies in humans. They also plan to investigate using their injectable hydrogel to deliver immune cells to treat cancer or in vaccines to protect against viral infections.

Researchers led by Columbia University have demonstrated that an experimental ultrasound treatment – delivered to nerves near the kidney – successfully produced clinically meaningful reductions in blood pressure. Called renal denervation, the brief pulses of ultrasound reportedly worked for people whose hypertension did not respond to a triple cocktail of medications.

In a 2019 clinical study following over 100 patients for six months pointed to promising positive results: the simple surgical procedure involves threading a catheter up to the renal arteries via an artery in the leg. Ultrasound energy is then used to, “thermally ablate and disrupt the renal sympathetic nerves while sparing the renal arterial wall.”

A newer study that recruited 136 patients with severe treatment-resistant hypertension showed that daytime ambulatory systolic blood pressure had dropped an average of eight points in patients receiving the renal denervation procedure, compared to a drop of just three points in the patients receiving a sham procedure – and this was observed just two months post-treatment.

“For patients with drug-resistant hypertension, a drop in blood pressure of eight points – if maintained over longer-term follow-up – is almost certainly going to help reduce the risk of heart attack, stroke, and other adverse cardiac events,” said cardiologist Dr. Ajay Kirtane, from Columbia University Vagelos College of Physicians and Surgeons.

“These results suggest that renal denervation has potential to become an important add-on to medication therapy – including for those who have difficulty managing several medications to control their hypertension. Additional studies will be needed to determine if this therapy may be effective for other groups, including older patients with hypertension and those with chronic kidney disease.”

The treatment has not yet been approved for clinical use by the FDA, but the researchers are hopeful.

Read: Isometric resistance training shown to safely reduce high blood pressure

An expansive study led by researchers at the University of Exeter, UK, is the first to find that increasing differences in the blood pressure between each arm is linked to poorer cardiovascular health – the greater this differential in pressure, the greater the patient’s risk of heart attack, stroke and early death.

Blood pressure rises and falls in a cycle with each pulse. Large differences in blood pressure measurements (measured in millimeters of mercury/mmHg) may be a sign of blocked or stiffening arteries, or some other factor affecting blood flow. International hypertension guidelines recommend that physicians record blood pressure in both arms at the initial consultation and if there is a difference of greater than 20 mmHg, then further investigation is warranted.

In this global study, concerning nearly 54,000 people from Europe, the US, Africa and Asia, university GP Dr. Chris Clark and colleagues investigated how inter-arm differences tracked with heart attacks, strokes and death over a 10-year period.

The researchers found that every mmHg of difference between the systolic, or maximum, pressure, in each arm corresponded with a one percent increase in the subject’s chance of experiencing new angina, a heart attack or stroke in the following 10 years.

“It really is critical to measure both arms to establish which patients may be at significantly increased risk. Patients who require a blood pressure check should now expect that it’s checked in both arms, at least once,” said Dr. Clark.

Read: Isometric resistance training shown to safely reduce high blood pressure

A cardiology professor from Dupuytren University Hospital in France, Victor Aboyans, pushes to include this information into future guidelines and clinical practice in assessing cardiovascular risk. “We believe that a 10 mmHg difference can now reasonably be regarded as an upper limit of normal for systolic inter-arm blood pressure, when both arms are measured in sequence during routine clinical appointments.”

The research, which was published in the Archives of Internal Medicine, studied more than 20,000 people with heart disease. It found that there was no difference in the number of heart attacks, strokes, or even deaths among the people surveyed who were randomly assigned to take either fish oil supplements or fish-oil-free placebo pills.

Said JoAnn Manson, professor of epidemiology at Harvard University, who co-wrote a commentary published with the study, “There is a common perception that fish oil supplements have been proven to prevent cardiovascular disease, and in fact the evidence has been incosistent and inconclusive.”

“Long-term studies are needed,” added Manson. “But for now people should continue to take at least two servings of fatty fish a week.”

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