Category: Cardiovascular Disease

Women are Less Likely to Undergo Critical Heart Surgery

A scientific presentation at the 57th Annual Meeting of The Society of Thoracic Surgeons revealed that women are less likely to have a coronary artery bypass grafting (CABG) using guideline-recommended approaches, possibly resulting in worse post-surgery outcomes.

CABG is a major surgical operation involves bypassing atheromatous blockages in a patient’s coronary arteries with venous or arterial conduits harvested from elsewhere in the patient’s body.

Dr Oliver Jawitz and colleagues from Duke and The Johns Hopkins University School of Medicine used the STS Adult Cardiac Surgery Database (containing records of nearly all CABG procedures done in the US), and identified adult patients from 2011 to 2019 who underwent first-time isolated CABG, along with detailed demographic, clinical and procedural data.

The association between female sex and three different CABG surgical techniques from US and European guidelines was investigated. Grafting of the left internal mammary artery to the left anterior descending artery, complete revascularisation, and multiarterial grafting have been linked to better short and/or long-term outcomes. Despite this, the results indicated that women were 14%-22% less likely than men to undergo CABG procedures with these revascularisation strategies.

“With these findings, we did in fact see less aggressive treatment strategies with women,” said Dr Jawitz. “It is clear that sex disparities exist in all aspects of care for patients with coronary artery disease (CAD), including diagnosis, referral for treatment, and now, in surgical approaches to CABG. We must ensure that female patients undergoing CABG are receiving evidence-based, guideline-concordant techniques.”

The results are in accordance with an overall neglect of heart disease treatment in women. Women are much more likely than men to have non-typical symptoms of heart disease which are also subtler, such as abdominal pain and fatigue, as well as having their own particular set of risk of factors. This is compounded by women being underrepresented in cardiac disease study cohorts.

Women’s health historically focused on mother and child, and breast cancer. As such, the period from symptom onset to diagnosis and treatment is longer, allowing the disease to progress and worsen outcomes. This is also reflected by fewer women being referred for beneficial treatments such as CABG. 


“Delayed diagnosis of CAD in women leads to late initiation of key behavioral and pharmacologic interventions for minimizing heart disease risk, as well as delayed referral for invasive diagnostic and therapeutic procedures, including surgical revascularisation with CABG,” said Dr Jawitz. “This often means that by the time female patients undergo these procedures, they have more severe disease than males, as well as a greater number of comorbidities, which leads to worse outcomes.

“Now that we have identified specific differences in surgical approaches to CABG between females and males, we must further elucidate how these differences result in disparate outcomes such as increased mortality, readmissions, and complications,” he concluded. “These findings will help inform the development of sex-specific guidelines for the diagnosis and management of cardiovascular disease.”

Source: News-Medical.Net

Moderate Alcohol Has an Immediate Effect on the Heart

One or two drinks a day may make for a healthy heart, but people with atrial fibrillation (AFib) may experience immediate impacts, as a new study reveals.

University of California, San Francisco (UCSF) researchers found that alcohol immediately changed the electrical properties driving heart muscle contraction in patients undergoing a treatment for AFib. These subjects were randomised to receive an infusion of alcohol maintained at the lower limit of legal intoxication, An equal number of control subjects who instead received a placebo infusion did not have this occur. The work was published January 27, 2021 in the Journal of the American College of Cardiology: Clinical Electrophysiology,

Senior study author Gregory Marcus, MD, professor of medicine in the Division of Cardiology at UCSF explained: “The acute impact of exposure to alcohol is a reduction in the time needed for certain heart muscle cells in the left atrium to recover after being electrically activated and to be ready to activated again, particularly in the pulmonary veins that empty into the left atrium.”    

AFib is the most common cardiac rhythm disorder, affecting some 1% of the world’s population, and is characterised by tachyarrhythmia. It is caused by abnormal electrical activity in the atria of the heart, making them fibrillate. This causes the atria to pump blood inefficiently, leading to feelings of the heart pounding, fluttering or skipping a beat. Due to turbulence caused by the irregular rhythm, a clot could form which could lead to a stroke. This results in some 158 000 deaths in the US annually. Other negative impacts include fatigue, weakness, dizzy lightheadedness, difficulty breathing and chest pain.

The study patients were undergoing a catheter ablation procedure. This is commonly used to suppress AFib by severing the electrical connection between the pulmonary veins and the left atrium. This areas was also the area noted to be affected by alcohol in the study.

Preparation for the ablation therapy required installation of catheters and electrodes in the heart chambers to monitor and pace the heart, and destroy selected tissue. The study measured refractory time before cells could again transmit electrical signals, and conduction speeds, as well as a stimulus inducing more AFib events. Electrical conduction speed and induced AFib events did not vary, but a 12 millisecond delay was seen in tissue around the pulmonary vein in the alcohol infusion group.

“Although epidemiological studies have found an association between self-reported alcohol consumption and the development of an atrial fibrillation diagnosis, ours is the first study to point to a mechanism through which a lifestyle factor can acutely change the electrical properties of the heart to increase the chance of an arrhythmia,” Marcus said. The same changes caused by alcohol infusion in the study have earlier been associated with episodes of AFib in previous computer models and animal studies, he said.
“Patients should be aware that alcohol can have immediate effects that are expected to increase risk for arrhythmias,” Marcus concluded.

However, in a separate study, injecting ethanol into the vein of Marshall when performing a catheter ablation seemed to increase the odds of treatment success compared to catheter ablation alone.

Source: MedicalXpress

Large Study Casts Doubt on “Fat but Fit”

New Spanish research casts doubt on the “fat but fit” paradox, where it is thought that physical fitness is enough to eliminate cardiovascular disease (CVD) risk.

Overweight and obesity is a worldwide problem that is greatly contributing to the burden of noncommunicable diseases, including CVD. A high body mass index (BMI) is strongly associated with CVD risk factors, such as hypercholesterolaemia, hypertension and diabetes. The cardiovascular complications arising from overweight and obesity are driven by processes such as inflammation, insulin resistance, endothelial dysfunction, coronary calcification. Some evidence suggested that physical activity was cardioprotective, partly or completely eliminating the CVD risk from disease – the “fat but fit” paradox.

A recent meta-analysis showed that cardiovascular fitness was a better predictor of cardiovascular disease over overweight/obesity, suggesting that perhaps public health programmes should emphasise fitness over control of body weight. To this end, the researchers sought to confirm if the “fat but fit” paradox was real.

The researchers gathered data from workers’ health insurance, with participants aged 18-64 grouped into normal weight, overweight and obesity by BMI, and into regularly active ( >150 min moderate physical activity or equivalent per week), insufficiently active (less than regularly active) and inactive (no physical activity at all). They were further separated by age, sex, smoking status and residential address.

Approximately 42%, 41%, and 18% of participants had normal weight, overweight, or obesity, respectively; 63.5%, 12.3%, and 24.2% were inactive, insufficiently active, and regularly active; and 30%, 15%, and 3% had hypercholesterolaemia, hypertension, and diabetes.

However, the protective effect of physical activity was far less than the excess risk from overweight/obesity. So much so that even regularly active obese participants had two to five-fold risk increases over their inactive but normal weight peers in the risk factors.

The protective effect of physical activity in overweight/obesity remains controversial. Shortcomings of the study were that they did not control for diet, and only accounted for self-reported leisure time activities. However, the large study size, with over 500 000 participants, should put paid to the theory that a physically active lifestyle can completely eliminate the deleterious effects of overweight/obesity.

The researchers concluded that, “weight loss per se should remain a primary target for health policies aimed at reducing CVD risk in people with overweight/obesity.”

Journal article source: European Journal of Protective Cardiology

Journal information: Pedro L Valenzuela, et al., Joint association of physical activity and body mass index with cardiovascular risk: a nationwide population-based cross-sectional study, European Journal of Preventive Cardiology, 2021;, zwaa151, https://doi.org/10.1093/eurjpc/zwaa151

New Study Has Good and Bad News on TIAs

There is both good and news on transient ischaemic attacks (TIAs) from a more than six-decade long study: TIAs are indeed harbingers of strokes, but also the incidence of post-TIA strokes has been falling over the decades.

A TIA is defined as a passing episode of neurologic dysfunction due to the focal brain, spinal cord, or retinal ischaemia, without acute infarction or tissue injury. The results were derived from the Framingham Heart Study had 14 059 participants and ran for over six decades, allowing for a more-complete picture of strokes that happen after a TIA. Of the participants, 435 had a TIA; these were compared against a second group of 2175 participants who did not have a TIA.

Even after accounting for other risk factors such as hypertension or diabetes, people who had experienced a TIA had a 4.5 to five times greater chance of a stroke. Study lead author Vasileios-Arsenios Lioutas, MD, said that the results show a need for intensive follow-up of TIA : “According to our findings, people continue to have a high risk of stroke for a sustained time after they’ve had a TIA. Therefore, one shouldn’t think that the high-risk period is just in the first 90 days after the attack and then one can relax. It seems these patients should be followed closely over time, keeping in mind that they are at risk for stroke and paying close attention to controlling their cardiovascular risk factors.”

The 66 years of study data was broken into three epochs. One- and five-year risks of post-TIA stroke in the 2000-2017 epoch were 7.6% and 16.1%, compared to 23.9% and 35.5% during the earliest epoch, from 1948 to 1985.

Sudha Seshadri, MD, professor of neurology at The University of Texas Health Science Center at San Antonio, said: “We examined 66 years of follow-up from Framingham participants, which allowed us to study trends over time. We can see that starting in the very early years of the Framingham study, the 1950s, moving on to the most recent times, the risk of subsequent stroke went down a lot.”

Source: News-Medical.Net

Journal information: Lioutas, V-A., et al. (2021) Incidence of Transient Ischemic Attack and Association With Long-term Risk of Stroke. JAMA.doi.org/10.1001/jama.2020.25071.

Blood Vessels Self-Reinforce After Aneurysms

Immediately following an aneurysm, blood vessels reinforce themselves by adapting collagen fibres to spread out the load, a study has found. 

An aneurysm is an abnormal bulge in the artery wall that can form in brain arteries. Brain aneurysms that rupture are fatal in nearly 50% of cases. In a rabbit model, the researchers used cutting-edge high-resolution microscopes to observe changes within the aneurysm, and observed that new collagen fibres laid down to deal with the strain and existing ones were re-oriented. Blood vessels had already been known to be able to reform and restructure over time, but this kind of primary restructuring is the first time that it has been observed, happening immediately after an event.  Instead of forming along the same direction, the blood vessels adapt to the different directions the new loads are in. 

Professor Anne Robertson at the University of Pittsburgh’s Swanson School of Engineering explained: “Imagine stretching a rubber tube in a single direction so that it only needs to be reinforced for loads in that direction. However, in an aneurysm, the forces change to be more like those in a spherical balloon, with forces pulling in multiple directions, making it more vulnerable to bursting. Our study found that blood vessels are capable of adapting after an aneurysm forms. They can restructure their collagen fibers in multiple directions instead of just one, making it better able to handle the new loads without rupturing.

“The first restructuring phase involves putting down a layer collagen fibres in two directions to deal with the new load, and the second phase involves re-orienting existing layers to adjust to these two directions, explained Chao Sang, who was a primary investigator on this research as part of his doctoral dissertation.

“The long-term restructuring is akin to a scar forming after a cut has healed, while this first phase that we observed can be thought of as having a role similar to clotting immediately after the cut–the body’s first response to protect itself,” added Robertson, who has a secondary appointment in the Swanson School’s Department of Bioengineering. “Now that we know about this first phase, we can begin to investigate how to promote it in patients with aneurysms, and how factors like age and preexisting conditions affect this ability and may place a patient at higher risk for aneurysm rupture

Source: News-Medical.Net

Journal information: Sang, C., et al. (2020) Adaptive Remodeling in the Elastase-Induced Rabbit Aneurysms. Experimental Mechanics. doi.org/10.1007/s11340-020-00671-9.

Religiosity-based Stress Linked to Cardiovascular Risk in South Asians

In a new study, the Study on Stress, Spirituality and Health (SSSH) linked proteomics from religiosity-based stress to cardiovascular disease (CVD) risk markers. This study marks the first investigation of protein levels associated with religion and spirituality in any group.

South Asians have an elevated CVD risk compared to other racial/ethnic groups, with the biological risk factors attributable to type 2 diabetes risk factors, and the rest stemming from traditional risk factors which show no enhancements as compared to other racial/ethnic groups.

“Before we can develop the best interventions to reduce CVD disparities, we need to understand the biological pathways through which health disparities are produced,” said principal investigator and co-senior author Alexandra Shields, PhD, associate professor of Medicine at Harvard Medical School (HMS). “As this study shows, psychosocial factors—and religious or spiritual struggles in particular—can affect biological processes that lead to CVD in this high-risk population. Spirituality can also serve as a resource for resilience and have a protective effect. Given that many of the minority communities that experience higher levels of CVD also report higher levels of religiosity and spirituality, studies such as the SSSH may help identify new leverage points, such as spiritually focused psychotherapy for those in spiritual distress, that could reduce risk of CVD for such individuals.”

The study had 100 South Asian participants, 50 diagnosed with CVD and 50 without. The participants were drawn from the Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study, which is following 1164 South Asian participants to investigate the factors that lead to heart disease among this racial/ethnic group. Three proteins were found to be involved in CVD risk after adjustment for diabetes (Contactin-5 [CNTN5], Low affinity immunoglobulin gamma Fc region receptor II-a [FCGR2A], and Complement factor B [CFB]), and of these, the expression of two (Contactin-5 and Complement factor B) were slightly modified by religious struggles interacting with adverse life events.

The results indicate that there may be unique protein expressions associated with CVD among individuals of South Asian descent, and these associations may be affected by religious struggles, such as feeling abandoned by God. “Understanding the pathways of this mechanism at the molecular level using proteomics technology is crucial to developing potential interventions that can help reduce CVD incidence in this population,” says Long H. Ngo, PhD., lead author and co-director of Biostatistics in the Division of General Medicine at BIDMC and associate professor of Medicine at HMS.

Co-senior author Towia Libermann, PhD, at Beth Israel Deaconess Medical Center, added: “The kinds of blood-based protein biomarkers used in this study are particularly effective in assessing CVD risk because they carry clinical information about risk of disease and are the most commonly used molecules for diagnostic applications.

Source: Medical Xpress

Journal information: Long H. Ngo et al, Plasma protein expression profiles, cardiovascular disease, and religious struggles among South Asians in the MASALA study, Scientific Reports (2021). DOI: 10.1038/s41598-020-79429-1

Omega-3 Carboxylic Acid Does not Prevent Recurrence of Heart Attacks

Omega-3 carboxylic acid (CA) is often prescribed by healthcare professionals to patients following a heart attack to lower the risk of a recurrence. However, new evidence from the STRENGTH trial shows that it has no effect in this regard.

Phase III of the STRENGTH trial involved 13 078 adult participants at 675 centres across 22 countries. They were randomised to either receive a 4gm of omega-3 CA medication or a maize oil placebo. All of the patients were being treated with statins and were at increased risk due to factors such as diabetes, or had experienced arterial blockages.

The participants were all monitored for rates of cardiovascular death, heart attack, stroke, need for coronary revascularisation or hospitalisation for unstable angina, starting in 2014 and concluding in 2020.

The trial was stopped slightly early due to the low likelihood of a benefit emerging from continuing to take omega-3 CA; furthermore, there was evidence of increased rates of atrial fibrillation among participants taking omega-3 CA.

Source: Science Daily

Women’s Heart Attack Death Risk Higher than Men’s

Compared to men, women have a 20% higher risk of death or heart failure after their first serious heart attack, according to an article in the journal Circulation. Prior research was unclear as to the difference in vulnerabilities to heart attack between the sexes.

The research focused on two types of heart attack; ST-segment elevation myocardial infarction (STEMI) and a less serious but more common type referred to as Non-STEMI or NSTEMI. Women were found to be at greater risk of death after either STEMI or NSTEMI attacks, although accounting for confounding variables narrowed this difference.

Women tended to be older (72) than men (61) at the age of their first serious heart attack, and had more complicated medical histories.

In the hospital setting, women were seen less frequently by a cardiovascular specialist (72.8%, versus 84% for men), prescribed fewer drugs and had fewer surgical procedures.

Lead author Justin A Ezekowitz, MBBCh, MSc, cardiologist and co-director of the Canadian VIGOUR Centre at the University of Alberta in Canada said, “Identifying when and how women may be at higher risk for heart failure after a heart attack can help providers develop more effective approaches for prevention. Better adherence to reducing cholesterol, controlling high blood pressure, getting more exercise, eating a healthy diet and stopping smoking, combined with recognition of these problems earlier in life would save thousands of lives of women—and men.”

Padma Kaul, PhD, co-director of the Canadian VIGOUR Centre, said that the next step is to address inequalities in provision of care: “Close enough is not good enough. There are gaps across diagnosis, access, quality of care and follow-up for all patients, so we need to be vigilant, pay attention to our own biases and to those most vulnerable to ensure that we have done everything possible in providing the best treatment.”

Source: Medical Xpress

A Bad Rap? Statins Have “Nocebo” Effect

According to an article by the BBC, new research funded by the Imperial Heart Foundation indicates that a significant portion of statins’ adverse side effects are attributable to the “nocebo” effect. 

Statins are one of the most prescribed tablets in the UK, used to lower low-density lipoprotein (LDL) cholesterol and triglycerides levels, and raise high-density lipoprotein (HDL) cholesterol. The effects help prevent heart attacks and stroke, but nearly a fifth of patients stop taking them due to side effects such as joint pain, muscle ache, fatigue and nausea. In 60 patients were recruited, who had all stopped taking statins due to their adverse effects. On a scale of 0 to 100, those taking placebo tablets reported a similarly high score (15.4) to those taking statins (16.3), compared to a group receiving no tablets (8).  The effect was so strong that many patients discontinued the dummy pills. 

The nocebo effect is the inverse of the placebo effect, where patients experience adverse effects even when they are taking a placebo. This is thought to explain why there is such a high prevalence of penicillin allergies when testing proves otherwise. 

Once the patients were talked through the nocebo effect, most were able to resume statins. It is not known as to why statins have such a powerful nocebo effect, although some attribute this to media creating a “self-fulfilling destiny”.

“If you stopped a man in the street and asked how do you feel about an aspirin or a statin a day, I think people would be much more positive about the aspirin,” said one of the researchers, Dr James Howard.

‘Flight or Flight’ Brain Region Linked to Heart Disease

Research on marmosets as reported in The Conversation has revealed the role that a region of the brain called sgACC plays in emotional arousal. Over-activity of sgACC was already associated with the dampening of pleasure and reward stimulus, seen in depression. 

A threat was presented to the marmosets in the form of a rubber snake and the marmosets were conditioned with a tone to create an association. The tone was later made without the snake to de-associate it from threat. The experimental group had over-activity induced in sgACC, the control group did not.

They found that marmosets who had not had sgACC over-stimulated responding normally to the de-association, calming down more quickly, but the over-activity group displayed fear and elevated blood pressure for much longer.

The over-activity of sgACC was also linked to abnormal heart function – increased heart rate and reduced variability in heart rate even at rest, without the presence of a threat.

Such changes reflect the presence of anxiety. The abnormal heart rates suggests that sgACC promotes the “flight or fight” response.
Brain imaging showed, with over-activity in sgACC, concurrent increased activity in the amygdala and hypothalamus, and reduced activity in the lateral prefrontal cortex, which is also seen in depression. Ketamine, a drug being investigated to treat depression, was shown to treat the depression aspects of sgACC over-activity, but in this case not anxiety – the marmosets remained fearful to stimulus.