Category: Cardiovascular Disease

Inflammatory Bowel Disease may Increase Risk of Heart Failure

Irritable bowel syndrome. Credit: Scientific Animations CC4.0

Inflammatory bowel disease (IBD) is associated with a slightly increased risk of heart failure up to 20 years after diagnosis, according to a comprehensive registry study from Karolinska Institutet published in the European Heart Journal.

The researchers analysed the risk of heart failure in over 80 000 patients with inflammatory bowel disease, that is, Crohn’s disease, ulcerative colitis or unclassified IBD, compared with 400 000 people from the general population, as part of the ESPRESSO study.

The results show that people with IBD have a 19% increased risk of developing heart failure up to 20 years after diagnosis. This corresponds to one extra heart failure case per 130 IBD patients in those 20 years, and the risk increase was seen regardless of the type of IBD. The highest risk of heart failure was seen in older patients, people with lower education and people with pre-existing cardiovascular-related disease at IBD diagnosis.

Contribute to new guidelines

“Both healthcare providers and patients should be aware of this increased risk, and it’s important that cardiovascular health is properly monitored,” says the study’s first author Jiangwei Sun, researcher at the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet. “We hope the results will raise the awareness of health workers as to the increased risk of heart failure in individuals with IBD and contribute to new guidelines for cardiovascular disease management in IBD patients.”

Comparing siblings with and without ABD, the risk increase was slightly lower, 10%, suggesting that genetics and early environmental factors shared within families may play a role. 

“We don’t know if there is a causal relationship, but we will continue to explore genetic factors and the role of IBD medications and disease activities on the risk of heart failure,” says the study’s senior author Professor Jonas F. Ludvigsson from the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet.

Source: Karolinska Institutet

Singing Repairs the Language Network of the Brain after Stroke

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Cerebrovascular accidents, or strokes, are the most common cause of aphasia, a speech disorder of cerebral origin. People with aphasia have a reduced ability to understand or produce speech or written language. An estimated 40% of people who have had a stroke have aphasia. As many as half of them experience aphasia symptoms even a year after the original attack.

Researchers at the University of Helsinki previously found that sung music helps in the language recovery of patients affected by strokes. Now, the researchers have uncovered the reason for the rehabilitative effect of singing. The recently completed study was published in the eNeuro journal.

According to the findings, singing, as it were, repairs the structural language network of the brain. The language network processes language and speech in the brain, which has been damaged.

“For the first time, our findings demonstrate that the rehabilitation of patients with aphasia through singing is based on neuroplasticity changes, that is, the plasticity of the brain,” says University Researcher Aleksi Sihvonen from the University of Helsinki.

Singing improves language network pathways

The language network encompasses the cortical regions of the brain involved in the processing of language and speech, as well as the white matter tracts that convey information between the different end points of the cortex.

According to the study results, singing increased the volume of grey matter in the language regions of the left frontal lobe and improved tract connectivity especially in the language network of the left hemisphere, but also in the right hemisphere.

“These positive changes were associated with patients’ improved speech production,” Sihvonen says.

A total of 54 aphasia patients participated in the study, of whom 28 underwent MRI scans at the beginning and end of the study. The researchers investigated the rehabilitative effect of singing with the help of choir singing, music therapy and singing exercises at home.

Singing is a cost-effective treatment

Aphasia has a wide-ranging effect on the functional capacity and quality of life of affected individuals and easily leads to social isolation.

According to Sihvonen, singing can be seen as a cost-effective addition to conventional forms of rehabilitation, or as rehabilitation for mild speech disorders in cases where access to other types of rehabilitation is limited.

“Patients can also sing with their family members, and singing can be organised in healthcare units as a group-based, cost-efficient rehabilitation,” Sihvonen says.

Source: University of Helsinki

New Blood Test for Ischaemic Stroke is a ‘Game-changer’

Ischaemic and haemorrhagic stroke. Credit: Scientific Animations CC4.0

A new study led by investigators from Brigham and Women’s Hospital has developed a new test by combining blood-based biomarkers with a clinical score to identify patients experiencing large vessel occlusion (LVO) stroke with high accuracy. Their results are published in the journal Stroke: Vascular and Interventional Neurology.

“We have developed a game-changing, accessible tool that could help ensure that more people suffering from stroke are in the right place at the right time to receive critical, life-restoring care,” said senior author Joshua Bernstock, MD, PhD, MPH, a clinical fellow in the Department of Neurosurgery at Brigham and Women’s Hospital.

Most strokes are ischaemic, in which blood flow to the brain is obstructed. LVO strokes are an aggressive type of ischaemic stroke that occurs when an obstruction occurs in a major artery in the brain, causing brain cells to rapidly die off from lack of oxygen. Major medical emergencies, LVO strokes require the swift treatment with mechanical thrombectomy, a surgical procedure that retrieves the blockage.

“Mechanical thrombectomy has allowed people that otherwise would have died or become significantly disabled be completely restored, as if their stroke never happened,” said Bernstock. “The earlier this intervention is enacted, the better the patient’s outcome is going to be. This exciting new technology has the potential to allow more people globally to get this treatment faster.”

The research team previously targeted two specific proteins found in capillary blood, one called glial fibrillary acidic protein (GFAP), which is also associated with brain bleeds and traumatic brain injury, and one called D-dimer. In this study, they demonstrated that the levels of these blood-based biomarkers combined with field assessment stroke triage for emergency destination (FAST-ED) scores could identify LVO ischaemic strokes while ruling out other conditions such as bleeding in the brain. Brain bleeds cause similar symptoms to LVO stroke, making them hard to distinguish from one another in the field, yet treatment for each is vastly different.

In this prospective, observational diagnostic accuracy study, the researchers looked at data from a cohort of 323 patients coded for stroke in Florida between May 2021 and August 2022. They found that combining the levels of the biomarkers GFAP and D-dimer with FAST-ED data less than six hours from the onset of symptoms allowed the test to detect LVO strokes with 93% specificity and 81% sensitivity. Other findings included that the test ruled out all patients with brain bleeds, suggesting that it may also eventually be used to detect intracerebral haemorrhage in the field.

Bernstock’s team also sees promising potential future use of this accessible diagnostic tool in low- and middle-income countries, where advanced imaging is not always available. It might also be useful in assessing patients with traumatic brain injuries. Next, they are carrying out another prospective trial to measure the test’s performance when used in an ambulance. They have also designed an interventional trial that leverages the technology to expedite the triage of stroke patients by having them bypass standard imaging and move directly to intervention.

“In stroke care, time is brain,” Bernstock said. “The sooner a patient is put on the right care pathway, the better they are going to do. Whether that means ruling out bleeds or ruling in something that needs an intervention, being able to do this in a prehospital setting with the technology that we built is going to be truly transformative.

Source: Brigham and Women’s Hospital

Infertility Treatment Associated with Double the Risk of Postpartum Cardiovascular Disease

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A study by Rutgers Health experts of more than 31 million hospital records shows that infertility treatment patients were twice as likely as those who conceived naturally to be hospitalised with heart disease in the year after delivery. The results were published in the Journal of Internal Medicine.

Compared to those who conceived naturally, patients who underwent infertility treatment 2.16 times as likely be hospitalised for hypertension.

“Postpartum checkups are necessary for all patients, but this study indicates they are particularly important for patients who undergo infertility treatment to achieve a conception,” said Rei Yamada, an obstetrics and gynaecology resident at Rutgers Robert Wood Johnson Medical School and lead author of the study.

The study authors say their results support standards of care that now call for an initial postpartum checkup three weeks after delivery, standards that some health systems have yet to adopt. Much of the elevated risk came in the first month after delivery, particularly for patients who developed dangerously high blood pressure.

“And these results aren’t the only ones to indicate that follow-up should occur early,” said Cande Ananth, chief of the Division of Epidemiology and Biostatistics in the Department of Obstetrics, Gynecology, and Reproductive Sciences at Rutgers Robert Wood Johnson Medical School and senior author of the study. “We have been involved in a series of studies over the past few years that have found serious risks of heart disease and stroke to various high-risk patient populations within those initial 30 days after delivery – risks that could be mitigated with earlier follow-up care.”

The study analysed the Nationwide Readmissions Database, which contains nationally representative data on about 31 million hospital discharges and readmissions per year. The database contains diagnosis codes, which let researchers find specific populations and identify reasons for readmission.

The researchers used data from more than 31 million patients who were discharged following delivery from 2010 to 2018, including 287 813 patients who had undergone any infertility treatment.

Although infertility treatment predicted a sharply elevated risk of heart disease, the study authors said the relative youth of infertility treatment patients kept their overall risk fairly low. Just 550 of every 100 000 women who received infertility treatment and 355 of every 100 000 who conceived naturally were hospitalized with cardiovascular disease in the year after delivery.

The cause of the elevated risk of heart disease associated with infertility treatment remains unclear. The increase in heart disease could stem from the infertility treatments themselves, the underlying medical issues that made patients infertile or some other cause.

“Looking forward, I’d like to see if different types of infertility treatment and, importantly, medications are associated with different risk levels,” said Yamada. “Our data gave no information about which patients had undergone which treatment. More detailed information might also provide insight into how infertility treatment impacts cardiovascular outcomes.”

Source: Rutgers University

New Drug Improves Oxygen Uptake in Patients with Hypertrophic Cardiomyopathy

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People with hypertrophic cardiomyopathy were able to use significantly more oxygen while exercising after taking an investigational drug in an international clinical trial, according to a study published today in the New England Journal of MedicineThe finding was also presented at the European Society of Cardiology’s Heart Failure 2024 meeting in Lisbon, Portugal.

The randomised, double-blind Phase 3 trial has 282 participants and is evaluating the experimental drug aficamten, which was developed by Cytokinetics to treat the obstructive form of hypertrophic cardiomyopathy, or HCM.

“By having more oxygen available during exercise, patients with obstructive hypertrophic cardiomyopathy can more easily walk, perform household chores, and do other everyday tasks,” said cardiologist and paper co-author Ahmad Masri, MD, MS. Masri directs the Oregon Health & Science University Knight Cardiovascular Institute’s Hypertrophic Cardiomyopathy Center. “Our latest clinical trial results suggest aficamten is a promising treatment for HCM.”

HCM affects about 1 in 500 people and is one of the most common causes of sudden death for youth and otherwise healthy athletes. Often caused by inherited gene mutations, it thickens heart muscles and makes it difficult for the heart to work as it should. It causes shortness of breath and reduces people’s ability to exercise. The obstructive form of HCM reduces blood flow out of the heart.

About half of the trial’s participants randomised to aficamten. Scientists measured the participants’ oxygen levels while they used treadmills or bicycles. Those who took aficamten had a significant increase in their maximum oxygen use – 1.7mL/kg/min more than those in the control group taking placebo.

Having an increased peak oxygen uptake can improve a patient’s ability to be physically active, whereas reduced oxygen uptake can increase the risk of experiencing heart failure, needing a heart transplant, and dying.

A safer alternative

Non-drug treatment options for obstructive HCM include surgery to remove excess heart muscle. In 2022, the Food and Drug Administration also approved mavacamten as the first drug designed to target the underlying cause of obstructive HCM. However, mavacamten may increase the risk of heart failure and it interacts with several commonly used medications. As a result, patients who use mavacamten must also undergo intense monitoring.

During the past decade, OHSU has been involved in many research studies exploring new HCM treatment options. It has been a centre for several mavacamten studies and is participating in gene therapy research. The university is also currently involved in four other aficamten trials that are evaluating it as a potential treatment for various forms of HCM and in different types of patients, including children.

“This is an exciting time for treating HCM,” Masri said. “While we continue to offer traditional surgical and procedural therapies for HCM, we are now also able to offer patients other treatment options: therapies that were recently approved by the FDA and investigational therapies that are available by participating in clinical trials.”

Source: Oregon Health & Science University

Exercise, New Drug Class Recommended for Management of Hypertrophic Cardiomyopathy

Human heart. Credit: Scientific Animations CC4.0

The American College of Cardiology (ACC) and the American Heart Association (AHA) today released a new clinical guideline for effectively managing individuals diagnosed with hypertrophic cardiomyopathy (HCM). The guideline, published in Circulation, reiterates the importance of collaborative decision-making with patients who have HCM and provides updated recommendations for the most effective treatment pathways for adult and paediatric patients.

HCM is an inherited cardiac condition most often caused by a gene mutation that makes the heart muscle too thick (hypertrophy), which impairs its ability to adequately pump blood throughout the body. HCM affects approximately 1 in every 500 individuals; however, a significant portion of cases remain undiagnosed because many people do not exhibit symptoms. Occasionally, the first time HCM is diagnosed is after a sudden death. People who do have symptoms may experience episodes of fainting, chest pain, shortness of breath or irregular heartbeats.

“Incorporating the most recent data, this new guideline equips clinicians with the latest recommendations for the treatment of HCM,” said Steve R. Ommen, MD, FACC, medical director of the Mayo Hypertrophic Cardiomyopathy Clinic and chair of the guideline writing committee. “We’re seeing more evidence that patients with HCM can return to their normal daily lives with proper care and management.”

Updated recommendations in the guideline reflect recent evidence about HCM treatment and management including new forms of pharmacologic management; participation in vigorous recreational activities and competitive sports; and risk stratification for sudden cardiac death (SCD) with an emphasis on pediatric patients.

The guideline includes recommendations for adding cardiac myosin inhibitors, a new class of medication for patients with symptomatic obstructive HCM who do not get adequate symptom relief from first-line drug therapy. Symptomatic obstructive HCM is a type of HCM where the heart muscle is restricted. Cardiac myosin inhibitors are the first FDA-approved class of medication to specifically target the thickening of the heart muscle instead of treating the symptoms, however they are monitored under the FDA’s Risk Evaluation and Mitigation Strategies (REMS) program, which may create additional steps and time for both the clinician and the patient. Clinicians require special training to prescribe the medication, and patients require regular screenings.

“These new drugs offer an alternative for patients who have failed first-line therapy and either want to delay or possibly avoid more aggressive options,” Ommen said. “With this guideline, we’re providing clinicians with point-of-care guidance about effectively using this first-in-class, evidence-based treatment option and improving their patients’ quality of life.”

In addition to medication treatment, growing evidence is showing that the benefits of exercise outweigh the potential risks for patients with HCM. Low to moderate intensity recreational exercise should be part of how HCM patients manage their overall health. For some HCM patients, competitive sports may be considered in consultation with HCM clinical specialists.

“Recommendations for physical activity continue to evolve with research,” Ommen said. “As part of a healthy lifestyle, patients with HCM are now encouraged to engage in low-to-moderate intensity physical activities. We’re seeing how vigorous physical activities can be reasonable for some individuals. With shared decision-making between the clinician and the patient, some patients may even be able to return to competitive sports.”

Poorly managed HCM may lead to many complications including SCD. The new guideline includes recommendations for assessing and managing the risk of SCD by establishing clear risk markers. Guidance for integrating risk markers with tools to estimate an individual patient’s SCD risk score is recommended to aid in the patient/clinician shared decision-making regarding implantable cardioverter defibrillator placement, incorporating a patient’s personal level of risk tolerance and specific treatment goals including quality of life.

Several recommendations in the new guideline extend to paediatric patients. A specific paediatric risk stratification for SCD is emphasised, with risk calculators specific to children and adolescents and stressing the importance of HCM centres with expertise in paediatrics. The new guideline extends exercise stress testing recommendations to include children diagnosed with HCM to help determine functional capacity and provide prognostic feedback.

Source: American College of Cardiology

Age-related Brain Changes Affect Stroke Recovery, Study Finds

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A new study by a global team of researchers has revealed that areas of age-related damage in the brain relate to motor outcomes after a stroke – a potentially under-recognised phenomenon in stroke research. The study was published in Neurology.

A stroke often leads to motor impairment, which is traditionally linked to the extent of damage to the corticospinal tract (CST), a crucial brain pathway for motor control. Signaling along the CST is involved in a variety of movements, including walking, reaching, and fine finger movements like writing and typing. However, stroke recovery outcomes aren’t fully predicted by damage to the CST, suggesting other factors are at play.

The new observational from the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery working group. It examines how one such factor could be white matter hyperintensities (WMHs) – areas of age-related damage in the brain’s white matter, which represent vascular dysfunction and are known to impact cognitive functions. The goal of the ENIGMA Stroke Recovery working group is to understand how changes in the brain after stroke relate to functional outcomes and recovery. ENIGMA Stroke Recovery has data from over 2100 stroke patients collected across 65 research studies and 10 countries, comprising the most extensive multisite retrospective stroke data collaboration to date.

Study leader Sook-Lei Liew, PhD, said: “We are grateful for our many collaborators around the world who lead independent stroke research programs and who are willing to come together and enable large-scale investigations into these critical questions about the role of overall brain health in stroke recovery and rehabilitation.” Dr Liew is an associate professor at the Keck School of Medicine of USC.

The study analysed data from 223 stroke patients across four countries and found that larger WMH volumes were associated with more severe motor impairment after a stroke (e.g., difficulty moving or using their arm for daily tasks), independent of CST damage. WMHs are related to chronic hypertension, diabetes, high cholesterol, and smoking, among other factors and conditions, and have been strongly related to cognitive impairment, but not extensively studied in the context of motor impairment. Interestingly, the relationship between CST damage and motor impairment varied based on WMH severity. Patients with mild WMHs showed a typical relationship between CST damage and motor impairment, while patients with moderate to severe WMHs did not have this relationship. Instead, motor impairment was related to WMH volume, not CST damage.

These findings suggest that WMHs, indicative of cerebrovascular damage from a variety of sources, could provide additional context to understand an individual’s potential for recovery post-stroke. Therefore, assessing WMH volume could improve predictive models for stroke recovery.

“WMHs are related to overall cardiovascular and brain health as we age. By integrating assessments of age-related brain health, we may be better able to predict stroke recovery and tailor rehabilitation to individual needs. This personalised approach could open avenues to improve outcomes after stroke,” says lead author Jennifer K. Ferris, PhD, of Simon Fraser University.

The researchers’ next step is to pursue longitudinal studies to confirm their findings. This insight lays the groundwork for developing more accurate markers for recovery, which could transform post-stroke care and rehabilitation.

Source: Keck School of Medicine of USC

Top Medical Minds Gather to Address Diabetes Threat

South Africa has seen the quickest and most alarming rise of diabetes on the continent; from an estimated 1.9 million people living with the condition in 2011 to 4.2 million by 2021 – with 7.5 million predicted to be afflicted by 20451. South Africa also has the fastest rising prevalence on the continent with an estimated 20% of the adult population either diabetic or pre-diabetic1. Globally, diabetes prevalence is predicted to rise by 46% between 2019 and 20452. It currently stands at some 537 million people worldwide1.

This emerged at the recently held annual Sanofi medical meeting, the Cardio-Metabolic Axis Forum from April 19th–21st in Cape Town. This was a meeting of leading endocrinologists, specialist physicians, nephrologists, diabetes-treating doctors, academics and Patient Advocacy Groups (PAGs).

Speaking at the conference, specialist physician and endocrinologist, Dr Landi Lombard – former editor of the South Africa Journal of Diabetes and Vascular Disease – told delegates that the risk of death associated with diabetes in cardiovascular conditions is more than twice that of people with non-diabetes, while in all-cause mortality, it’s just under twice that of a person living without diabetes. Of the estimated 537 million people living with diabetes globally, only about half are diagnosed, of whom 25% receive care, 12.5% achieve treatment targets, and 6% live a life free of diabetes-related complications1.

Dr Lombard said that the pandemic is being driven by poor lifestyle choices and diet, lack of exercise and widespread obesity in the population, so better healthcare worker communication and education of patients is vital to stem the tide of diabetes.

Professor Robert Ritzel of the Department of Endocrinology, Diabetology and Angiology at Schwabing Hospital in Munich, said the Pacific Islands and the Middle East led the world with diabetes prevalence at between 25 % and 40 %. He said what precipitated a surge in diabetes was the speed at which a nation changed from a traditional to a modern lifestyle. When this happened within a few years, diabetes prevalence was likely to range between 20% and 40%. However, when change occurred over many generations, it gave epidemiologists and clinicians time to adapt.

Lombard said one of the biggest challenges was what diabetologists called ‘therapeutic inertia’ which contributes to a patient living with sub-optimal blood sugar control for many years. This term embraced physician, patient and healthcare system factors, patient injection related factors, time and resource constraints among physicians and the lack of a proper healthcare system plan. He said that in people with Type 2 diabetes, the median time it takes for the disease to intensify while taking one or more anti-diabetic drugs is 2.9 years. However, the use of an injectable slowed intensification down to 7.2 years or more.

Reasons for failure to intensify treatment or progress to injectable therapies varied between specialist and primary care physicians but were mainly because of a patient fear of injection, too many injections, perceptions of this being a ‘last resort’ treatment, fear of weight gain, fear of low blood sugar, and poor communication with patients.

Lombard said even 1 year of poor blood sugar control in people with Type 2 diabetes could result in an increase in the cumulative incidence of kidney disease of 18%, neuropathy of 8%, retinopathy of 7% and a significantly increased risk of heart attack (67%), heart failure (64%), stroke (51%) and composite cardiovascular events (62%).

Professor Naomi ‘Dinky’ Levitt, former Head of Endocrinology and Diabetic Medicine at the University of Cape Town and Groote Schuur Hospital and Director of the Chronic Disease Initiative for Africa, highlighted gestational diabetes as one of the greatest challenges.

Described as the “doyenne” of endocrinology in South Africa (SA), Levitt said one third of women who have gestational diabetes go on to develop diabetes within 6 years of giving birth, so post-partum intervention is crucial.

According to Levitt, lifestyle interventions had about a 20% positive effect, mainly because new mothers were pulled in all directions by family, the baby, husband, and domestic and work needs.

She said that with 31.4% of SA women estimated to have developed gestational diabetes, it would be ideal to screen all pregnant women at 24 and 28 weeks. However, this would collapse the healthcare system because of the healthcare staffing demands, so the alternative was to focus on risk factors such as being over 30 years old or being overweight.

She said that focusing on women with gestational diabetes would have the greatest impact on the pandemic, as treatment can help avoid pre-eclampsia and improve foetal development, resulting in fewer admissions to the neonatal ICU.

Speaking on behalf of Sanofi the conference sponsor, Dr Asafika Mbangata said: “Sanofi puts patients first and the aim of the conference was to empower stakeholders with the right information to help make critical care decisions for patients by sharing the latest data on advancements in treatments and technologies, along with insights into global and local policy changes impacting diabetes care.”

“As we chase the miracles of science to improve people’s lives, we know we cannot shape the future of diabetes management without partnerships with healthcare professionals and other stakeholders. Collaboration across all medical disciplines is essential if we are to overcome this pandemic, and we’re hopeful the conference opened the door to future robust collaborative actions that improve patient outcomes,” concluded Dr Mbangata.

References

  1. Adapted from IDF Diabetes Atlas (10th edition). International Diabetes Federation. 2022. http://www.diabetesatlas.org/. Accessed 23 April, 2024.
  2. IDF Facts and Figures. https://idf.org/about-diabetes/diabetes-facts-figures/. Accessed 7 May, 2024.

High Prevalence of Hidden Brain Changes in People with Heart Disease

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A new analysis involving over 13 000 people has found changes to blood vessels in the brain that can increase the risk of stroke and dementia are common in people with a range of heart conditions, regardless of whether they have experienced a stroke.

The new research, published in Neurology®, the medical journal of the American Academy of Neurology, is the most comprehensive systematic review of ‘hidden’ brain changes in people with a range of heart conditions to date.

Lead author Dr Zien Zhou from The George Institute for Global Health said that identifying these changes could play an important role in choosing treatments for these patients.

“Although people with heart disease are two to three times more likely than the general population to have changes in their brain’s vascular system, they’re often overlooked, because these patients don’t routinely undergo brain imaging unless they have suffered a stroke,” he said.

“But it can make them more susceptible to the risk of brain bleeds from medications commonly used to treat or prevent blood clots – intracranial haemorrhage is a life-threatening complication with no proven treatment and a survival rate of less than 50 percent.”

Changes to blood vessels in the brain that can only be detected by brain imaging such as silent brain infarction (SBI) and cerebral small vessel disease (CSVD) are known to occur more commonly in older people or those who have hypertension.

While not sufficient to cause obvious neurological symptoms, they can result in subtle neurological deficits and increase the longer-term risk of stroke or dementia.

To determine the prevalence of these hidden or covert cerebrovascular changes in adults with atrial fibrillation, coronary artery disease, heart failure or cardiomyopathy, heart valve disease, and patent foramen ovale (a hole in the heart), George Institute researchers conducted a meta-analysis of 221 observational studies published between 1988 and 2022.

The findings showed that in people with heart disease:

  • approximately one third had any form of SBI
  • a quarter had lacune (small cavities where neural tissue has died after a previous blockage or leakage from small arteries)
  • two-thirds had white matter lesions (damage to the protective coating around nerve fibres)
  • a quarter had evidence of asymptomatic microbleeds in the brain tissue, and
  • over one half had brain atrophy (a shrinking of the brain due to loss of neurons or connections between neurons).

The prevalence of these brain changes was generally the same between those with and without a recent stroke and there were no apparent sex differences in the results.

Dr Zhou said the study also confirmed that heart disease is one of the main causes of these changes that reflect brain ‘frailty’.

“While several potential mechanisms of the association between heart disease and hidden cerebrovascular injury have been proposed, the two conditions share common risk factors such as ageing, hypertension, type 2 diabetes, hyperlipidaemia, and smoking,” said Dr Zhou.

“It’s possible that a gradual decline in cardiac output in some patients with heart disease might affect how much blood is reaching the brain tissue, contributing to vascular changes and cognitive dysfunction in these patients,” he added.

“It’s also possible that hidden brain changes and cognitive dysfunction are a consequence of tiny blood clots traveling to the brain through the arterial circulation after forming in the heart.”

Dr Zhou said that more research was needed to look at the exact causes of these brain changes and the implications for managing these patients.

“We need to know whether performing an additional MRI in those considered for anticoagulation therapy – which is required for most people with heart disease – would be cost-effective in terms of preventing unwanted side effects,” he said.

“But refining the risks of brain clots and bleeds from anticoagulants and using this information to make the best treatment choice could improve treatment safety for people with heart disease.”

Source: George Institute for Global Health

Study Finds New Genetic Markers for Blood Pressure

NIH-led study finds genetic markers that explain up to 12% of the differences between two people’s blood pressure.

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National Institutes of Health researchers and collaborators have discovered over 100 new regions of the human genome, also known as genomic loci, that appear to influence a person’s blood pressure. Results of the study also point to several specific genomic loci that may be relevant to iron metabolism and a type of cellular receptor known as adrenergic receptors. 

The study, published in Nature Geneticsis one of the largest such genomic studies of blood pressure to date, including data from over 1 million participants and laying the groundwork for researchers to better understand how blood pressure is regulated. Such insights could point to potential new drug targets. 

“Our study helps explain a much larger proportion of the differences between two people’s blood pressure than was previously known,” said first author Jacob Keaton, PhD. “Our study found additional genomic locations that together explain a much larger part of the genetic differences in people’s blood pressure. Knowing a person’s risk for developing hypertension could lead to tailored treatments, which are more likely to be effective.” 

Hypertension often runs in families, meaning that there is a genetic component to developing the condition in addition to environmental contributions such as a high-salt diet, lack of exercise, smoking and stress.

To understand the genetics of blood pressure, the researchers combined four large datasets from genome-wide association studies of blood pressure and hypertension. After analysing the data, they found over 2000 genomic loci linked to blood pressure, including 113 new regions. Among the newly discovered genomic loci, several reside in genes that play a role in iron metabolism, confirming previous reports that high levels of accumulated iron can contribute to cardiovascular disease.  

The researchers also confirmed the association between variants in the ADRA1A gene and blood pressure. ADRA1A encodes a type of cell receptor, called an adrenergic receptor, that is currently a target for blood pressure medication, suggesting that other genomic variants discovered in the study may also have the potential to be drug targets to alter blood pressure. 

“This study shows that these big genome-wide association studies have clinical relevance for finding new drug targets and are needed to discover more drug targets as we go forward,” said Dr Keaton. 

From these analyses, the researchers were able to calculate a polygenic risk score, which combines the effects of all genomic variants together to predict blood pressure and risk for hypertension. These risk scores consider which genomic variants confer risk for hypertension and reveal clinically meaningful differences between people’s blood pressure. 

Polygenic risk scores have potential to serve as a useful tool in precision medicine, but more diverse genomic data is needed for them to be applicable broadly in routine health care. While the collected data was mostly from people of European ancestry, the polygenic risk scores were also applicable to people of African ancestry.

Source: National Institutes of Health