Tag: cardiovascular disease

Categories : Cardiovascular DiseaseTags :

Angioplasty Needed by Smokers 10 years Before Non-smokers

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Smokers needed their blocked arteries fixed nearly 10 years earlier than non-smokers, and patients with obesity underwent these procedures four years earlier than non-obese patients, according to a new US study.

Angioplasty is a nonsurgical procedure that opens clogged or narrow coronary arteries. The procedure involves inserting an inflatable balloon-tipped catheter through the skin in extremities and then inflating the balloon once it reaches the stenosed arterial site. The balloon pushes the atherosclerotic intraluminal plaque against the arterial wall and restores the luminal diameter, and so restores blood flow to the heart muscle.

The study included patients with no heart attack history, treated at hospitals across Michigan. The patients had all undergone angioplasty and/or stenting to widen or unblock their coronary arteries and restore blood flow. Nearly all of them had at least one traditional risk factor, including smoking, obesity, high blood pressure, high cholesterol and diabetes. Most patients had three or more.

Furthermore, compared to men, women generally had their first procedure at a later age. Over the past ten years, among patients undergoing their first angioplasty or stent procedure, obesity and diabetes rates have increased, while smoking and high cholesterol have decreased.

“Smoking is a completely preventable risk factor,” said senior author Devraj Sukul, MD, MSc, an interventional cardiologist and a clinical lecturer at the University of Michigan Health Frankel Cardiovascular Center. “If we direct additional efforts at preventing smoking and obesity we could significantly delay the onset of heart disease and the need for angioplasty and stenting.”

“In Michigan, we will work to help every smoker quit at the time of cardiac care because it is an unmatched teachable moment for patients,” said Michael Englesbe, M.D., a surgeon and professor at Michigan Medicine who serves as portfolio medical director for the Collaborative Quality Initiatives.

Source: Medical Xpress

Journal information: Zoya Gurm et al, Prevalence of coronary risk factors in contemporary practice among patients undergoing their first percutaneous coronary intervention: Implications for primary prevention, PLOS ONE (2021). DOI: 10.1371/journal.pone.0250801

Categories : Cardiovascular DiseaseTags :

New Measurement of Heart Function Could Benefit High-risk Heart Patients

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A new measurement of heart function developed at UVA Health could improve survival for people with heart failure by identifying high-risk patients who require tailored treatments, according to a new study.

The study is the first to show a survival benefit from wireless pressure monitoring sensors implanted in the pulmonary arteries. Pulmonary artery proportional pulse pressure, or PAPP, is a new measure of heart function that can identify patients at very high risk of hospitalisation or death from systolic heart failure or pulmonary hypertension (high blood pressure in the heart and lungs).

Previous work showed that patients with low PAPPs were at much higher risk than those with higher PAPPs, so the researchers tested whether these benefits were maintained in patients undergoing implantation of pressure sensors that continuously monitor pressure in the pulmonary artery.

“We found that PAPP is a very good measure of how stiff or compliant the pulmonary arteries are. The stiffness of the pulmonary arteries determines how much resistance the right side of the heart has overcome to pump blood effectively to the lungs,” said Sula Mazimba, MD, MPH, a heart failure expert at UVA Health and the School of Medicine. “The importance of this simple measure is that it can identify patients that are at greatest risk of dying or being hospitalised. This allows us to tailor more aggressive treatments.”

Heart failure causes more than 1 million hospital admissions each year, and approximately half of patients die within five years of diagnosis.

The new study evaluated the benefits of PAPP monitoring in patients with systolic heart failure, where the left ventricle is weak, as well as those with pulmonary hypertension.

To find out if PAPP monitoring could predict outcomes in these patients, Dr Mazimba and colleagues analysed data from 550 participants in the CHAMPION clinical trial, whose participants were randomised to receive an implantable, wireless heart monitor called the CardioMEMS HF System.

They found that participants with a below-average PAPP had a significantly higher risk of hospitalisation or death compared with those with higher PAPPs. Furthermore, the monitoring  reduced the risk of death for those with low PAPPs by 46% annually during two to three years of follow-up.

“The implications of this study are highly significant,” said co-investigator Kenneth Bilchick, MD, MS, a cardiologist at UVA Health. “We now have identified a specific group of patients who appear to have a marked improvement in survival with implantation of these pulmonary artery wireless monitors. As a result, the findings of the study could maximise the impact of this technology for a large number of potential candidate patients. This is an excellent example of how secondary analyses of clinical databases maintained by the National Institutes of Health can result in novel and personalised approaches to patient care.”

The researchers say further study is necessary to gauge the full potential of PAPP monitoring to improve care for patients with heart failure, but early results were encouraging.

“In the past, the function of the right chamber of the heart was often ignored and considered to be inconsequential to the overall performance of the heart, but we are now learning that this is not the case,” Dr Mazimba said. “Having tools that signal when the right side of the heart is under strain may aid clinicians to adopt timely tailored treatments for heart-failure patients.”

Source: UVA Health

Categories : Cardiovascular Disease Implants and ProsthesesTags :

Ventricular Assist Device Pulled from Market due to Failures

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Photo from Olivier Collett on Unsplash
Photo from Olivier Collett on Unsplash

The HeartWare system, a left ventricular assist device (LVAD) for advanced heart failure patients, is being discontinued immediately, according to the Food and Drug Administration.

The manufacturer, Medtronic, is halting global distribution and sale of its HeartWare system in the wake of observational evidence of increased neurological adverse events and mortality for its LVAD compared with similar mechanical circulatory support (MCS) devices.

Last December, some HeartWare LVADs were recalled because of complaints that the pump may delay or fail to start. So far 100 of these complaints have been received, including 14 patient deaths and 13 cases where an explant was necessary, the FDA noted.

“We have been carefully monitoring the adverse events associated with this device and support its removal from the marketplace,” said Bram Zuckerman, MD, director of the Office of Cardiovascular Devices at the FDA’s Center for Devices and Radiological Health, in a statement.

Medtronic now advises physicians to immediately stop new implants of the HeartWare device, but does not recommend explants.

The company is working on a plan for ongoing support of the some 4000 patients around the world who currently have this LVAD. It received commercial approval for use in the US in November 2012.

The FDA named Abbott’s HeartMate 3 as one alternative LVAD for patients with end-stage heart failure. This device features a magnetic levitation system that keeps the rotor separate without mechanical contact.

“The FDA is working closely with both Medtronic and Abbott to ensure patient care is optimised during this transition period and that there is an adequate supply of devices available to provide this patient population with options for end-stage heart failure treatment,” said Dr Zuckerman.

In a separate press release, Abbott reassured the public that it has the ability to meet increased demand for MCS devices as a result of HeartWare withdrawal from clinical use.

Source: MedPage Today

Categories : Cardiovascular Disease GenderTags :

Heart Risk in Transgender Men Receiving Hormones

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A study of transgender people receiving gender-affirming hormone therapy found that certain hormones increased certain cardiometabolic risk factors. 

Gender-affirming or cross-sex hormone therapy is integral to the management of transgender individuals, but there is only limited understanding of the effects of such hormones on cardiovascular health. Research is limited by the absence of large cohort studies, lack of appropriate control populations, and inadequate data acquisition from gender identity services. Existing epidemiological data suggest that the use of oestrogens in transgender females increases the risk of myocardial infarction and ischaemic stroke. Conversely, testosterone use in transgender males is currently lacking any consistent or convincing evidence of increased risk of cardiovascular or cerebrovascular disease.

This retrospective study included 129 transgender individuals receiving gender-affirming hormone therapy. In transgender males receiving testosterone, there was an average 2.5% drop in HDL cholesterol levels seen each year of using gender-affirming hormone therapy (P=0.03). However, researchers did not see this change in transgender females on estradiol during the average 48-month follow-up period. Additionally, the researchers found no significant changes in LDL cholesterol, triglycerides, HbA1c, or 25-hydroxyvitamin D levels in transgender males or transgender females.

About 53% of the participants in the study identified as transgender males, and more than 60% of the cohort was white. The median age of the total cohort was 26 with a BMI of 25.5. The majority of transgender males were on intramuscular injectable preparations of testosterone cypionate.

Similar to prior studies, a significant decrease in HDL was noted in TM on testosterone therapy. The researchers noted that further study is needed on the correlation of this finding with changes in diet and exercise while on testosterone therapy and impact on cardiovascular events. Reassuringly, no other changes noted in cardiovascular parameters.

“Further long-term data is needed for patients receiving this hormone therapy to assure that their long-term cardiovascular risk is optimised,” concluded Samihah Ahmed, MD, MBA, of Northwell Health Lenox Hill Hospital in New York City, who presented the findings.

Source: MedPage Today

Presentation information: Ahmed S, et al “Cardiometabolic risk factors in transgender individuals taking gender-affirming hormone therapy through four years” AACE 2021. 

Categories : Cardiovascular Disease New Compounds and TreatmentsTags :

Averting Heart Failure by Shutting Down a Heart Protein

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Photo from Olivier Collett on Unsplash
Photo from Olivier Collett on Unsplash

Shutting down a protein found in cardiac muscle could be a new mechanism to treat post-heart attack heart failure, according to research led by the University of Cambridge.

New drugs are needed to improve the heart’s pumping ability after damage from a heart attack. Drugs that strengthen the contraction of failing heart muscle have been deemed unsafe, leaving a gap in the heart attack and heart failure armamentarium.

Researchers now believe that they might have identified a new drug target—a protein called MARK4.

In research funded by the British Heart Foundation (BHF), Cambridge scientists found levels of MARK4 were elevated in mouse hearts after a heart attack. When they compared mice with and without MARK4 in the heart, they found hearts lacking the protein pumped blood 57% more efficiently. This protective effect was seen 24 hours after a heart attack and persisted over the entire follow-up period of four weeks.

The team was first in identifying that MARK4 fine-tunes a structural network within the heart muscle cell—called the microtubule network—that attaches to the machinery governing heart muscle cells contraction and relaxation. When MARK4 levels were increased after a heart attack, microtubules were tightly anchored onto the contractile machinery in the heart, increasing resistance and hindering normal function. When MARK4 levels were reduced, microtubules were loosely anchored, making contraction and relaxation easier.

Following a heart attack the speed of contraction in MARK4-lacking muscle cells increased by 42 percent and the speed of relaxation increased by 47 percent, compared to muscle cells from mice that had the MARK4 protein. They were also almost on par with healthy heart muscle performance, attesting to the power of reducing MARK4.

Based on these findings, the researchers suggested that drugs to switch off MARK4 could be a new way to improve recovery and help the heart to pump blood more efficiently in people with failing hearts.

Dr Xuan Li, BHF Intermediate Research Fellow at University of Cambridge BHF Centre of Research Excellence, said: “After years of research we’ve revealed an entirely new and promising way that could help the recovery of failing hearts.

“It’s early days, and we now need to test the longer-term effects of switching off MARK4. But if drugs to do that prove successful, the life-changing benefits could be seen in people with other types of heart disease as well as those who’ve had a heart attack and developed heart failure.”

Professor Metin Avkiran, Associate Medical Director at the British Heart Foundation, said: “Heart attacks are a major cause of disability worldwide—people who’ve had a major heart attack are at much greater risk of developing chronic heart failure. There are around 920 000 people living with heart failure in the UK, and we desperately need drugs to drastically improve the heart’s function in these patients.

“These findings are a positive step forward. Further research is needed to refine and test drugs that can target MARK4 before we’ll see them given to people who’ve had a heart attack and develop heart failure.”

Source: University of Cambridge

Categories : Cardiovascular Disease Mental HealthTags :

Study Links OCD to Increased Risk of Stroke

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Adults with obsessive-compulsive disorder (OCD) were more than three times as likely to have an ischaemic stroke later in life compared to adults who do not have OCD, according to new research.

OCD involves intrusive thoughts which may be accompanied by actions to alleviate the stress brought on by these thoughts; these are called obsessions and compulsions, respectively. Potentially debilitating, OCD typically manifests in adolescence and is under-reported and under-treated. The World Health Organization ranks OCD as one of the ten most disabling conditions worldwide, with a lifetime prevalence of 1% to 3%.

Clinical research has shown that patients with OCD often have stroke-related metabolic disorders, such as obesity and diabetes. 

While a growing body of evidence suggests an association between OCD and stroke risk, with some patients developing OCD after a stroke, OCD may also influence stroke risk. OCD raises the risk for ischaemic stroke more than 3-fold, especially among older adults
Drawing on health records from 2001-2010 from the Taiwan National Health Insurance Research Database, researchers compared stroke risk between 28 064 adults diagnosed with OCD and 28 064 adults without an OCD diagnosis. The average age at diagnosis was 37 years old, with equal representation of men and women, with a maximum data coverage of 11 years.

Analysis showed that even after controlling for factors known to increase stroke risk such obesity and high blood pressure, OCD remained an independent risk factor for ischaemic stroke. However, no differences were found when considering hemorrhagic strokes, and medications to treat OCD were linked to increased risk of stroke.
Ya-Mei Bai, MD, PhD, Professor, Department of Psychiatry, Taipei Veterans General Hospital, said: “The results of our study should encourage people with OCD to maintain a healthy lifestyle, such as quitting or not smoking, getting regular physical activity and managing a healthy weight to avoid stroke-related risk factors.”

Worldwide, stroke is the second-leading cause of death after heart disease. Cerebrovascular diseases often present complex cases, and this study was the first to consider how OCD and strokes may be associated on a longer time scale. 

Limitations include the observational nature of the study being unable to establish cause and effect, as well as the inclusion in the data of only stroke patients who sought health care. Additionally, information on disease severity and outcome was not included along with family medical history or environmental influences, which can further affect both the extent of OCD and severity of strokes.

“For decades, studies have found a relationship between stroke first and OCD later,” said Prof Bai. “Our findings remind clinicians to closely monitor blood pressure and lipid proles, which are known to be related to stroke in patients with OCD. More research is needed to understand how the mental processes connected to OCD may increase the risk of ischaemic stroke.”

Source: News-Medical.Net

Journal information: Chen, M-H., et al. (2021) Increased Risk of Stroke in Patients With Obsessive-Compulsive Disorder: A Nationwide Longitudinal Study. Stroke: Journal of the American Heart Association. doi.org/10.1161/STROKEAHA.120.032995.

Categories : Metabolic DisordersTags :

Familial High Cholesterol Often Eludes Genetic Testing

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Image source: National Cancer Institute/Unsplash

Most familial hypercholesterolemia (FH) cases would go undetected if people were to rely on array-based genetic tests alone, a new study suggests.

FH predisposes people to elevated levels of LDL cholesterol, which can lead to premature coronary artery disease and early death.  

For example, the 23andMe test, which has a limited screen for only 24 known FH variants, would have missed over 60% of individuals with the autosomal dominant disorder. This figure was even worse for non-European ancestry individuals.

“Limited-variant screens may falsely reassure the majority of individuals at risk for FH that they do not carry a disease-causing variant, especially individuals of self-reported Black/African American and Hispanic ancestry,” according to Amy Sturm, of the Geisinger Genomic Medicine Institute in Danville, Pennsylvania, and colleagues.

In their study, limited-variant screening would miss nearly 94% and 85% of Black and Hispanic individuals with confirmed FH pathogenic variants. However this would be true for only a third of Ashkenazi Jewish people.

“The reduced yield of limited-variant screening could result in a major health care disparity for groups already affected by social and medical disenfranchisement that beget serious health disparities including a significantly higher rate of cardiovascular death among Black/African American individuals,” the investigators said.

“When FH is strongly clinical suspected, even if array-based FH reporting has negative results, a clinical genetic test should still be considered,” according to an accompanying note by JAMA Cardiology editors Pradeep Natarajan, MD, MMSc, of Massachusetts General Hospital and Harvard Medical School in Boston, and Elizabeth McNally, MD, PhD, of Northwestern University Feinberg School of Medicine in Chicago.

“Genetic databases overrepresent European ancestry populations and therefore make interpretation of genetic variation more accurate in these cohorts. However, even 64% of the FH mutations in European American individuals would have been missed by the 24-variant [test],” noted Drs Natarajan and McNally.

“Unfortunately, genetic testing for FH is underused, with 90% of affected individuals worldwide remaining undiagnosed and only 3.9% of patients with FH in the U.S. having a record of genetic testing,” noted Dr Sturm and colleagues.

“Recent expert statements recommend that patients suspected of having FH be offered genetic testing and that first-degree relatives of genetically positive individuals be screened for FH by lipid profile or genetic testing,” according to them.

Comprehensive genetic testing with next-generation sequencing (NGS) detects over 2000 potentially pathogenic variants within full genomes. Assay-based screens such as 23andMe only test for a small subset of known variants, and not the number present.

Both types of genetic tests for FH are available either in clinical settings or as a direct service to consumers.

“Whether testing is obtained directly by a consumer or through a clinical setting, those tested should consult with a genetic counselor or other qualified health care professional to fully understand the benefits and limitations of the different types of genetic testing for FH,” Sturm’s group urged.

For the study, the authors took deidentified NGS results, sourced from a single clinical laboratory, for gene panels of individuals receiving comprehensive genetic testing either for an FH indication (4563 participants) or as proactive health screening (6482 participants).

The researchers had tested both cohorts for more than 2000 possible variants in four FH-associated genes: LDLR, APOB, PCSK9, and LDLRAP1.

With the limited screening tests, only 8.4% of people with FH indication had a positive detection, compared to 27.0% for comprehensive NGS genotyping. In the proactive cohort of people with no clinical suspicion of FH, clinically significant FH variant prevalence was about one in 191 according to the comprehensive test.

A limitation was the researchers’ inability to confirm genetic testing results with medical and family histories.

Source: MedPage Today

Journal information: Sturm AC, et al “Limited-variant screening vs comprehensive genetic testing for familial hypercholesterolemia diagnosis” JAMA Cardiol 2021; DOI: 10.1001/jamacardio.2021.1301.

Categories : Cardiovascular DiseaseTags :

Unexpected Discovery Opens Up Stroke and Cardiac Arrest Treatments

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Image source: Pixabay

In a surprising discovery, researchers at Massachusetts General Hospital (MGH) identified a mechanism that protects the brain from the effects of hypoxia. This serendipitous finding, which they report in Nature Communications, could help develop therapies for strokes, as well as brain injury resulting from cardiac arrest.

However, this study began with a very different objective, explained senior author Fumito Ichinose, MD, PhD, an attending physician in the Department of Anesthesia, Critical Care and Pain Medicine at MGH, and principal investigator in the Anesthesia Center for Critical Care Research. Ichinose and his team are developing techniques for inducing suspended animation, a state similar to hibernation where a human’s body functions are temporarily slowed or halted for later revival. 

Ichinose believes that the ability to safely induce suspended animation could have valuable medical applications, such as pausing the life processes of a patient with an incurable disease until an effective therapy is found. Often seen in science fiction, and currently studied by NASA, it could also allow humans to travel long distances in space.

A 2005 study found that inhaling a gas called hydrogen sulfide caused mice to enter a state of suspended animation. Hydrogen sulfide, which smells like rotten eggs, is sometimes called ‘sewer gas.’ Oxygen deprivation in a mammal’s brain leads to increased production of hydrogen sulfide. As this gas accumulates in the tissue, hydrogen sulfide can halt energy metabolism in neurons, causing them to die. Oxygen deprivation is a hallmark of ischaemic stroke, the most common type of stroke, and other injuries to the brain.

At first, Dr Ichinose and his team set out to study the effects of exposing mice to hydrogen sulfide repeatedly, over an extended period. At first, the mice entered a suspended-animation-like state—their body temperatures dropped and they were immobile. “But, to our surprise, the mice very quickly became tolerant to the effects of inhaling hydrogen sulfide,” said Dr Ichinose. “By the fifth day, they acted normally and were no longer affected by hydrogen sulfide.”

Interestingly, the mice that became tolerant to hydrogen sulfide were also able to tolerate severe hypoxia. Ichinose’s group suspected that enzymes in the brain that metabolise sulfide might be responsible for this. They discovered that levels of one particular enzyme, called sulfide:quinone oxidoreductase (SQOR), rose in the brains of mice when they breathed hydrogen sulfide for several days. They thus hypothesised that SQOR plays a role in resistance to hypoxia.

Nature has strong evidence for this; for example, female mammals resist hypoxia better than males—and the former have higher levels of SQOR. When SQOR levels are artificially reduced in females, their hypoxia resistance drops. (Oestrogen may be responsible for the observed increase in SQOR, as the hypoxia protection is lost when a female mammal’s estrogen-producing ovaries are removed.) Additionally, some hibernating animals, such as the thirteen-lined ground squirrel, are highly tolerant of hypoxia, which allows them to survive as their bodies’ metabolism slows down during the winter. The brain of a typical ground squirrel has 100 times more SQOR than that of a similar-sized rat. However, when the researchers ‘switched off’ expression of SQOR in the squirrels’ brains, they lost their protection against the effects of hypoxia.

Meanwhile, when the researchers artificially increased SQOR levels in the brains of mice, “they developed a robust defense against hypoxia,” explained Dr Ichinose. His team increased the level of SQOR using gene therapy, currently a technically complex, impractical approach. On the other hand, the team demonstrated that ‘scavenging’ sulfide, using an experimental drug called SS-20, reduced levels of the gas, thereby sparing the brains of mice when hypoxic.

Human brains have very low levels of SQOR, meaning that even a modest accumulation of hydrogen sulfide can be harmful, said Dr Ichinose. “We hope that someday we’ll have drugs that could work like SQOR in the body,” he says, noting that his lab is studying SS-20 and several other candidates. Such medications could be used to treat ischemic strokes, as well as patients who have suffered cardiac arrest, which can lead to hypoxia. Dr Ichinose’s lab is also investigating how hydrogen sulfide affects other parts of the body. For example, hydrogen sulfide is known to accumulate in other conditions, such as certain types of Leigh syndrome, a rare but severe neurological disorder usually leading to early death. “For some patients,” said Dr Ichinose, “treatment with a sulfide scavenger might be lifesaving.”

Source: Medical Xpress

Journal information: Eizo Marutani et al, Sulfide catabolism ameliorates hypoxic brain injury, Nature Communications (2021). DOI: 10.1038/s41467-021-23363-x

Categories : Cardiovascular DiseaseTags :

Number and Birth Order of Siblings Affect Risk of Cardiovascular Events

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Photo by Wayne Lee-Sing on Unsplash
Photo by Wayne Lee-Sing on Unsplash

According to a large population study in Sweden, first-born children have a lower risk of cardiovascular events than brothers and sisters born later, but people who are part of a large family with many siblings have an increased risk of these events. The findings were published in the online journal BMJ Open.

While the influence of family history – that is, the health of parents and grandparents – on a person’s health, including cardiovascular risk, is well known, there is now growing interest in how the make-up of a person’s immediate family influences health.

For their large population study, the authors drew on data on 1.36 million men and 1.32 million women born between 1932 and 1960 and aged 30–58 years in 1990 from the Multiple-Generation Register in Sweden. They retrieved data from national registers on fatal and non-fatal cardiovascular and coronary events over the next 25 years.

Analysis of the data showed that first-borns had a lower risk of non-fatal cardiovascular and coronary events than siblings born later. First-born men had a higher risk of death than second and third-born siblings, while first-born women had a higher risk of death than second-born siblings, but equal to further siblings.

Looking at family size, compared with men with no siblings, men with one or two siblings had a lower risk of cardiovascular events, while those with four or more siblings had a higher risk.

Similarly, compared with men with no siblings, men with more than one sibling had a reduced risk of death, whereas those that had three or more siblings had an increased risk of coronary events.

A similar pattern was seen in women. Compared with those without siblings, women with three or more siblings had an increased risk of cardiovascular events, while those with two or more siblings had an increased risk of coronary events. Women with one or more siblings had a lower risk of death.

Since this was an observational study, it cannot establish cause. The authors also noted  some limitations, including that the Swedish registers included no information on diagnostic procedures and there no data were available concerning lifestyle factors, such as body mass index, smoking and diet.

The researchers took into account socioeconomic status, obesity, diabetes, chronic lung disease (COPD) and alcoholism and related liver disorders. They also note that some of their findings conflict with those from previous studies.

The researchers noted that, given the wide variation among countries of policies to support families and the number of children, their findings could have implications for public health.

“More research is needed to understand the links between sibling number and rank with health outcomes,” they say. “Future research should be directed to find biological or social mechanisms linking the status of being first born to lower risk of cardiovascular disease, as indicated by our observational findings.”

Source: BMJ Open

Journal information: Sibling rank and sibling number in relation to cardiovascular disease and mortality risk: a nationwide cohort study, BMJ Open (2021). DOI: 10.1136/bmjopen-2020-042881

Categories : Cardiovascular Disease Medical Research & TechnologyTags :

New Early Warning System for Sudden Cardiac Death

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Photo from Olivier Collett on Unsplash
Photo from Olivier Collett on Unsplash

Researchers at Tomsk Polytechnic University have developed a nanosensor-based system that can detect early abnormalities in the function of cardiac muscle cells, which otherwise can be recorded only with invasive procedures.

The nanosensor-based hardware and software complex can measure cardiac micropotential energies without filtering and averaging-out cardiac cycles in real time. The device allows registering early abnormalities in the function of cardiac muscle cells, which otherwise can be recorded only during open-heart surgery or by inserting an electrode in a cardiac cavity through a vein. Such changes can lead to sudden cardiac death (SCD). Nowadays, there are no alternatives to the Tomsk device for a number of key characteristics in Russia and the world. ).

The main method of detection of electrical pulses in the heart is electrocardiography (ECG). Nevertheless, ECG modern devices detect already critical changes in the function of the myocardium.

“Therefore, there is much concern about the creation of devices for early detection of these disorders, when it is still possible to restore cell function using medication and without surgical intervention. To implement this, it is required to record cardiac micropotential energies, electrical pulses emitted by separate cells. Here, there is a question of how to implement it noninvasive. Our research team have worked on this task for a long time, as a consequence, we jointly with the participation of our colleagues, doctors, have developed a hardware and software complex.

“The core principles of its operation are similar to ECG, however, we changed sensors: we made nanosensors instead of conventional sensors and managed to measure signals of nanovoltage and microvoltage layers without filtering and averaging-out in broadband. The use of nanosensors led to the necessity to apply original circuit solutions, write individual software.

“Ultimately, we gained a tremendous difference in sensitivity,” Diana Avdeeva, Head of the TPU Laboratory for Medical Engineering, a research supervisor of the project, said.

The system consists of a set of sensors, a tiny key device for recording incoming signals from sensors and data processing software. The sensors are fixed on a patient’s chest using a conducting gel, and the monitoring procedure takes about 20 minutes.

Conventional ECG machines operate on frequencies from 0,05 Hz to 150 Hz, while the device of the Tomsk scientists operates on much higher frequencies of up to 10 000 Hz.

“Silver chloride electrodes are usually used for recording ECG of high quality. Our sensors are also silver chloride electrodes, however, we used silver nanoparticles. There are up to 16 thin plates from porous ceramics in every our sensor, silver nanoparticles are placed in these pores. There are millions of particles in one sensor, where every particle is a silver chloride electrode capable to enhance an electric field of the heart. Silver and gold nanoparticles are capable to enhance an electromagnetic field: visible light by 10,000 folds and infrared radiation by 20 folds. We also refused to use filters for rejection network interference and noises, which are usually used in conventional ECG and significantly distort micropotentials,” Diana Avdeeva said.

The published study includes the monitoring data of one volunteer’s heart function, who took part in the research for four years and was monitored every 7-10 days.

“At the beginning of our research, we recorded clear violations of activity of cardiac muscle cells. His attending physician recommended surgery, he gained an inserted stent at the Cardiology Research Institute. Then, he continued to take part in the research and the device recorded the further gradual restoration of cardiac function,” the scientist noted.

“A task to create a sensitive, tiny and affordable complex was set up, in order in a long run, outpatient clinics and patients at home could use it. Moreover, the developed methods and devices can be used not only in cardiology.

“The fields of any electrophysiological research, such as electroencephalography, electromyography and so on are promising. Of course, before applying it to cardiology, we have to pass some essential stages. These are the collection of the required array of statistics, certification of the complex for medical use. All these stages require sponsorship, we are engaged in searching for partners and supporting programs,” said research team member Mikhail Yuzhakov, Engineer at the TPU Laboratory for Medical Engineering.

Source: Tomsk Polytechnic University