Portable MRI machines, an emerging technology that makes medical imaging accessible even in remote locations, detected ischaemic strokes in 90% of patients scanned, according to a study appearing in the journal Science Advances.
In previous studies, portable MRI devices have demonstrated they can also detect haemorrhagic as well as ischaemic strokes, helping clinicians make crucial life-saving treatment decisions quickly in remote areas for patients who lack ready access to major hospitals with expensive stationary MRI machines, the authors say.
“This is the first systematic evidence you can detect ischaemic strokes using portable, bedside devices,” noted Kevin Sheth, professor of neurology and neurosurgery at Yale School of Medicine and co-corresponding author of the study.
Outcomes for stroke patients improve dramatically the quicker they receive treatment. But access to stationary MRI machines is limited for those who live far away from major hospitals or in developing countries. And even stroke patients who have access to major hospitals often have to wait for scans with stationary MRIs because of heavy demand for the equipment. Portable scans can be used at a patient’s bedside, in ambulances, or in remote clinics, Dr Sheth said.
In addition, quickly differentiating between different types of stroke is crucial for determining proper treatment, the researchers say. Ischaemic strokes are usually treated with blood thinners. But that course of treatment is dangerous for those who experience haemorrhagic strokes or strokes in which there is bleeding in the brain.
Analysing portable MRI scans from 50 patients at Yale New Haven Hospital, the Yale and Harvard researchers found that the results largely confirmed ischaemic stroke diagnoses made by stationary MRIs. For 45 of those patients, the portable MRI detected blood clots as small as 4mm in size.
In patients undergoing angioplasty, a study showed that use of the paclitaxel-coated balloon catheter known as the Chocolate Touch device had better outcomes at compared with those from use of a commercially-available balloon catheter. These findings were presented at the American College of Cardiology’s 71st Annual Scientific Session.
The trial showed noninferiority and an improvement in terms of the proportion of patients with adequate blood flow through the artery without subsequent procedures.
“I’m very excited that we now have a head-to-head comparison of a second-generation vs. first-generation drug-coated balloon and data that we can rely on to make decisions for our patients,” said Mehdi Shishehbor, DO, MPH, PhD, the study’s lead author. “I think that the superiority of Chocolate Touch indicates that as we improve the technologies, there is additional benefit to be gained. For me, this study makes the case that this [Chocolate Touch] will be the device of choice between these two devices for patients who require drug-coated balloon therapy.”
The trial enrolled 313 randomised patients treated for superficial femoral and popliteal artery disease – conditions that involve blocked arteries in the upper leg. All patients underwent balloon angioplasty, a procedure to reopen the artery by threading a tiny device into the blocked area and inflating a small drug-coated balloon that helps prevent reoccurance of the blockage . In half of the patients, a commercially-available Lutonix drug-coated balloon was used, and in the other half the Chocolate Touch balloon was used. The Chocolate Touch device has a constrained balloon, creating characteristic pillows and grooves reminiscent of a chocolate bar.
At 12 months, 78.8% of the patients who received the Chocolate Touch device and 67.7% of those receiving the Lutonix device achieved patency, or blood flow as measured by the peak systolic velocity ratio. No statistical difference in safety was seen between the devices, with a rate of major adverse events of 11.1% in the Chocolate Touch arm and 15.4% in the Lutonix arm. Major adverse events included a composite of death related to the targeted limb, major amputation and revascularidation procedures.
Dr Shishehbor said that estimates of mortality on a cumulative, year-by-year basis are consistently lower in the Chocolate Touch arm as compared to the Lutonix arm. For patients at the three-year follow-up, estimated mortality is 6.8% among patients receiving the Chocolate Touch device, which was also well below the trial’s goal of 13.2%, reinforcing confidence in the device’s safety profile.
“At a minimum, this [Chocolate Touch] device is as safe as the Lutonix, with a trend for lower mortality rates,” Dr Shishehbor said.
The Chocolate Touch device is designed to provide a more even and controlled widening of the artery. This design lets operators use a slightly larger balloon to further widen the artery and provide increased contact between the balloon surface with the paclitaxel coating, Dr Shishehbor said.
Although balloon angioplasty is the preferred treatment for blocked arteries in the leg, many patients experience recurring blockages, requiring additional procedures.
“If we are able to offer patients therapies that can keep the artery open for as long as possible, that will be welcome news,” Dr Shishehbor said. “As we advance our technologies and get more patency, or blood flow, over time, the patients will enjoy that benefit and have a lower likelihood of needing repeat procedures.”
Dr Shishehbor said that the trial paused enrollment for six months in response to industry-wide concerns over the safety of paclitaxel but said that the study ultimately achieved a high follow-up rate of 94%. The trial is also the first to allow combining the drug-coated balloon treatment with atherectomy, in which a blade is used to first remove plaque from the vessel prior to catheter balloon use. Dr Shishehbor said that while only a small number of patients was treated with atherectomy, the patency rate was promising. Future studies could determine whether Chocolate Touch treat longer and more complex blockages.
A new study in the journal Radiology has found that the diameter of the thoracic aorta can be a biomarker for heart attacks and other adverse cardiovascular events in women and men, and has the advantage of being simple to add on to existing screening.
The thoracic aorta is divided into an ascending aorta that rises from the left ventricle of the heart and a descending aorta in the back of the chest.
While the thoracic aorta grows with age, but changes of vessel size and structure, a phenomenon known as vascular remodelling, have a systemic nature involving haemodynamic and biological processes that are also linked to cardiovascular disease.
“While enlargement of the thoracic aorta is a frequent finding in clinical practice, few longitudinal data regarding its long-term prognosis for major cardiovascular disease outcomes at the population level exist,” said study senior author Maryam Kavousi MD, PhD, from University Medical Center Rotterdam.
Dr Kavousi and colleagues assessed these associations in 2178 participants from the population-based Rotterdam Study. Participants underwent multi-detector CT scans between 2003 and 2006 and were followed for an average of 9 years. Thoracic aorta diameters were indexed for body mass index (BMI).
Larger BMI-indexed ascending and descending thoracic aortic diameters were significantly associated with increased risk of adverse cardiovascular outcomes like stroke and death in both women and men.
“Our results suggest that imaging-based assessment of diameter of thoracic aorta can be considered as a risk marker for future cardiovascular disease,” Dr Kavousi said.
In women, greater ascending aortic diameter was associated with 33% higher cardiovascular mortality risk. There seems to be a sex difference in remodelling of the ageing aorta, with faster deterioration in women.
“Ageing could affect aortic health and structure more adversely in women than in men,” Dr Kavousi said.
The study findings suggest that cardiovascular risk assessment associated with thoracic aortic size among asymptomatic women and men could lead to effective, sex-specific prevention strategies.
“As the aortic diameter is significantly related to body size, use of aortic diameters indexed for body measurements could improve its prognostic value for cardiovascular outcomes,” Dr Kavousi said.
Measurement of thoracic aorta size is an easy addition to current screening, the researchers said. The study made use of cardiac CT scans that are already commonly used to assess coronary calcium. Thoracic aortic diameter could also be measured routinely, for example as part of CT-based lung cancer screening.
The current study was based on a single CT-based assessment of thoracic aorta among a large group of participants from the general population, followed up for nine years for incidence of cardiovascular outcomes and mortality. The researchers have recently repeated the CT-based assessment of thoracic aorta among these participants after a median of 14 years.
“This provides an exciting and unique opportunity to study sex-specific risk profiles and patterns of growth in thoracic aorta in the general population,” Dr Kavousi said.
“For patients with allergic disorders, routine evaluation of blood pressure and routine examination for coronary heart disease should be given by clinicians to ensure early treatments are given to those with hypertension or coronary heart disease,” said Yang Guo, PhD, the study’s lead author.
An association between allergic disorders and cardiovascular disease was detected in prior research, findings which remained controversial, Dr Guo explained. The present study sought to determine whether an increased cardiovascular risk exists in adults with allergic disorders.
The study used 2012 data from the National Health Interview Survey (NHIS), a cross-sectional survey of the US population. In the allergic group were adults with at least one allergic disorder, including asthma, respiratory allergy, digestive allergy, skin allergy and other allergy. The study included a total of 34 417 adults, over half of whom were women, average age 48.5 years. The allergic group included 10 045 adults. The researchers adjusted for age, sex, race, smoking, alcohol drinking and body mass index; they also examined subgroups stratified by demographic factors.
Having a history of allergic disorders was found to be associated with increased risk of developing hypertension and coronary heart disease. Further analysis showed that individuals with a history of allergic disorders between ages 18 and 57 had a higher risk of hypertension. An increased risk of coronary heart disease was seen in male Black/African American participants between ages 39-57. Asthma was the largest contributor of risk of hypertension and coronary heart disease.
Dr Guo said that to confirmed these findings, large cohort studies with long-term follow-up are required. Discovering the underlying mechanism could also help with management.
A study published in JAMA Network Open showed that cereal fibre but not fruit or vegetable fibre, was consistently associated with lower inflammation and lower CVD incidence. Until now there had been limited data on the link between fiber and inflammation among older adults, who have higher levels of inflammation compared with younger adults.
The research includes data from a large and well-characterised prospective cohort of elderly individuals, with detailed data on dietary intake, inflammation, and incidence of CVD. The research confirmed previously observed associations between dietary fibre and CVD and extended those investigations to include the source of the fibre, the relationship of fibre with multiple inflammatory markers, and to test whether inflammation mediated the relationship between dietary fibre and CVD.
Of the 4125 adults enrolled in the Cardiovascular Health Study from 1989 to 1990 participants received a food frequency questionnaire that was administered to those without prevalent CVD at enrollment and then were followed up visits for development CVD (stroke, myocardial infarction, and atherosclerotic cardiovascular death) through June 2015. Blood samples were assessed for markers of inflammation.
“Higher intakes of dietary fiber is associated with lower CVD risk. A common hypothesis has been that higher fiber intakes reduce inflammation, subsequently leading to lower CVD risk,” said Rupak Shivakoti, PhD. ‘With findings from this study, we are now learning that one particular type of dietary fiber — cereal fibre — but not fruit or vegetable fibre was associated with lower inflammation. With findings from this study we now are learning that cereal fiber has the potential to reduce inflammation and will need to be tested in future interventional studies.”
Although there are data to suggest that fibre in general might have anti-inflammatory effects by improving gut function, modifying diet and satiety (eg, reduced fat and total energy intake), and improving lipid and glucose profile metabolism, why cereal fibre but not vegetable or fruit fibre is associated with lower inflammation is not clear and warrants further investigation, noted Dr Shivakoti. Additionally, it is unclear whether it is the cereal fibre itself or other nutrients in foods rich in cereal fibre behind the observed relationships.
“Additionally, we learned that inflammation had only a modest role in mediating the observed inverse association between cereal fiber and CVD,” observed Dr Shivakoti. “This suggests that factors other than inflammation may play a larger role in the cereal fiber-associated reduction in CVD and will need to be tested in future interventions of specific populations.
By tracking more than 38 000 participants from childhood for fifty years, researchers have uncovered direct evidence that the five cardiovascular risk factors when present in childhood predicted cardiovascular risk in adulthood.
Body mass index, blood pressure, cholesterol, triglycerides and youth smoking, particularly in combination in early childhood, were clinically linked with cardiovascular events that predict poor cardiovascular health in adults.
Paper co-author Prof Terence Dwyer at the University of Oxford commented: “Despite the effect medical and surgical care have had on treating heart disease, achieving the greatest possible reduction in the heart disease burden will depend on including preventive strategies that commence in childhood.”
The findings confirm that prevention must start in childhood. “Longitudinal studies like these have been hampered by a lack of inclusion of comprehensive childhood data around body measurements, blood pressure, and blood lipids and a failure to follow-up at ages when cardiovascular disease becomes common.”
The study involved 38 589 participants from Australia, Finland and the US, who were followed from age 3-19 years for a period of 35-50 years.
The results showed that increased risk for cardiovascular events was seen in over half the children, with those having the highest risk factor levels, at 9 times the risk for an event as for children with below average risk factors.
“While this evidence had not been available previously, the findings were not entirely surprising as it had been known for some time that children as young as five already showed early signs of fatty deposits in arteries. This new evidence justified a greater emphasis on programs to prevent the development of these risk factors in children. Clinicians and public health professionals should now start to focus on how this might best be achieved,” Prof Dwyer concluded.
A randomised controlled trial showed that people with heart failure receiving an annual flu shot had lower rates of pneumonia and hospitalisation on a year-round basis and a reduction in major cardiovascular events during peak flu season – but not year-round.
The study, presented at the American College of Cardiology’s 71st Annual Scientific Session, is the first randomised controlled trial to assess the benefits of the flu vaccine in people with heart failure, who face a high risk of cardiovascular events. It was conducted in countries across Asia, Africa and the Middle East where getting a flu shot is not commonplace.
Lead author Mark Loeb, MD, said: “Although our prespecified endpoints were not significant, our data suggest that there’s a clinical benefit [to getting a flu shot] given the clear reduction in pneumonia, moderate reduction in hospitalisation and reduction in vascular events and deaths during periods of peak influenza. When taken together with previous trials and observational studies, the collective data demonstrate there is a substantial benefit to receiving a flu vaccine for people with heart failure.”
Heart failure is a condition in which the heart becomes too weak or stiff to pump blood effectively. Previous studies have shown that people with heart disease or cardiovascular risk factors face an elevated risk of complications when they contract influenza, but there has been a lack of evidence on whether flu vaccines can help to mitigate this risk specifically in people with heart failure.
The trial enrolled 5129 patients with heart failure in 10 countries where flu vaccines are not common. Participants did not routinely get flu shots and had previously received a flu shot no more than once during the three years preceding the trial. Participants were randomised to receive a flu shot or a placebo annually for up to three years, though they could still get a flu shot outside of the trial. Researchers tracked health outcomes for a median of 2.9 years. The trial’s primary endpoint was a composite of death from cardiovascular causes, non-fatal heart attack or non-fatal stroke. Its co-primary endpoint included a composite of any of these events plus hospitalisation for heart failure.
Overall, the composite primary endpoint occurred in 691 participants and 1470 experienced the composite co-primary endpoint. When analysed on a year-round basis there was no significant difference in the rates of these events between those who had received a flu vaccine and those who had not.
Separate analyses of hospitalisation, pneumonia and other respiratory outcomes however found that rates of pneumonia were 42% lower and hospitalisations were down 15% among those who received a flu shot.
The flu vaccine arm showed a significant reduction in the first primary endpoint, as well as reductions in all-cause death and cardiovascular death, when the analysis was limited to periods of peak influenza circulation. When influenza circulation was low, no significant difference was seen.
The researchers accounted for the differences in influenza circulation seasons. Based on these results, researchers said the flu vaccine did help to protect patients from influenza complications, including cardiovascular events.
“Many of the effects we found during peak flu circulation disappeared outside of it,” Dr Loeb said. “There’s no biological explanation for that other than influenza infections.”
While the study was conducted in countries where the flu vaccine is either not widely available or not common to receive, Dr Loeb said the results could likely be generalisable even in countries where flu vaccine uptake is higher. Study participants were allowed to get a flu vaccine outside of the study, but Dr Loeb said that there was no impact on the findings as very few did so. He added that the study was stopped early in four countries due to the COVID pandemic.
Loeb said that additional trials and large-scale observational studies could further clarify the health benefits of influenza vaccination in people with cardiovascular disease.
“I think this study offers an important message about vaccines generally – that it is important to do randomised controlled trials in populations that historically haven’t had a very high uptake of vaccines,” Dr Loeb said. “These types of [research] gaps have to be filled.”
A new drug, mavacamten, shows promise in providing relief to cardiomyopathy patients experiencing shortness of breath, according to new research presented at the American College of Cardiology (ACC) Scientific Session.
Dr Florian Rader presented results of an international clinical trial showing that mavacamten alleviated the shortness of breath in patients with obstructive hypertrophic cardiomyopathy.
The genetic condition causes thickening of the heart muscle, and as a result, heart muscle cells enlarge and scarring often develops between cells. Patients with the condition typically experience shortness of breath, chest pressure, irregular heartbeat, and, although rare, sudden cardiac arrest.
“Until now, existing treatments for hypertrophic cardiomyopathy have been suboptimal, leaving most patients symptomatic and often, in need of invasive or even open-heart surgery,” said Dr Rader, who served as site principal investigator of the clinical trial at Cedars-Sinai Hospital. “Follow-up data from this extended clinical trial shows success in lessening the obstruction to blood flow out of the heart in hypertrophic cardiomyopathy. Along with this relief of obstruction came substantial improvements in symptoms and an important heart failure blood biomarker.”
As Dr Rader explained, mavacamten showed preliminary success in relieving symptoms associated with the condition – chiefly, shortness of breath, which can be debilitating.
Key data from the clinical trial includes:
The average age of the 231 clinical trial participants was 60 years old, and 39% of those on the trial were female. The median follow-up was 62 weeks.
69% of trial participants had improved shortness of breath after 48 weeks of treatment.
Treatment with mavacamten was generally well tolerated, and no new safety concerns were raised during longer-term follow-up.
Dr Rader said that no disease-specific targeted treatment options have been developed for the condition since it was first described some 60 years ago.
Though the prevalence of hypertrophic cardiomyopathy is roughly 1 in every 200 patients, Dr Rader said that the condition is thought to be widely underdiagnosed.
“A lot of patients have the condition and often feel short of breath or palpitations but their doctor doesn’t recognise these symptoms as stemming from hypertrophic cardiomyopathy,” Dr Rader said. “Instead, patients may be told by their physician they are out of shape, need to lose weight or are suffering from an anxiety condition.”
The correct approach, said Dr Rader, is to first pay close attention to the patient’s symptoms. If shortness of breath is a main concern, then a doctor should listen to the patient’s heart for a murmur, then follow up with an electrocardiogram, and, ultimately, an echocardiogram, which most often will lead to the correct diagnosis.
The SARS-CoV-2 virus can infect cardiac pacemaker cells, causing the cells to undergo self-destruct by ferroptosis according to a preclinical study reported in Circulation Research. This may explain the heart arrhythmias that are commonly observed in COVID patients.
In the study, the researchers used an animal model as well as human stem cell-derived pacemaker cells to show that SARS-CoV-2 can readily infect pacemaker cells and trigger a process called ferroptosis, where cells self-destruct, releasing damaging reactive oxygen molecules.
“This is a surprising and apparently unique vulnerability of these cells — we looked at a variety of other human cell types that can be infected by SARS-CoV-2, including even heart muscle cells, but found signs of ferroptosis only in the pacemaker cells,” said study co-senior author Professor Shuibing Chen.
Arrhythmias, including tachycardia and bradycardia, has been observed in some COVID patients, and multiple studies link these arrhythmias to worse COVID outcomes. But how the coronavirus caused these remained unclear.
In the new study, the researchers examined golden hamsters (one of the only lab animals that reliably develops COVID-like signs from SARS-CoV-2 infection) and found evidence that following nasal exposure, the virus can infect the sinoatrial node, which is the natural cardiac pacemaker.
The researchers then induced human embryonic stem cells to mature into cells closely resembling sinoatrial node cells. They showed that these induced human pacemaker cells can be infected by SARS-CoV-2 as they express ACE2 receptors. Large increases in inflammatory immune gene activity were also seen in the infected cells.
The team’s most surprising finding, however, was that the pacemaker cells, in response to the stress of infection, showed clear signs of a cellular self-destruct process called ferroptosis, which involves accumulation of iron and the runaway production of reactive oxygen molecules. The scientists were able to reverse these signs in the cells using compounds that are known to bind iron and inhibit ferroptosis.
“This finding suggests that some of the cardiac arrhythmias detected in COVID patients could be caused by ferroptosis damage to the sinoatrial node,” said co-senior author Dr Robert Schwartz
While COVID patients could in principle be treated with ferroptosis inhibitors specifically to protect sinoatrial node cells, antiviral drugs that block the effects of SARS-CoV-2 infection in all cell types would be preferable, the researchers said.
The researchers plan to continue to use their cell and animal models to investigate sinoatrial node damage in COVID and other settings.
“There are other human sinoatrial arrhythmia syndromes we could model with our platform,” said co-senior author Dr. Todd Evans. “And, although physicians currently can use an artificial electronic pacemaker to replace the function of a damaged sinoatrial node, there’s the potential here to use sinoatrial cells such as we’ve developed as an alternative, cell-based pacemaker therapy.”
Cedars-Sinai researchers have developed a clinical algorithm that is the first to be able to distinguish between treatable sudden cardiac arrest and untreatable forms of the condition. The findings, published in the Journal of the American College of Cardiology: Clinical Electrophysiology, may help prevent sudden cardiac arrest based on key risk factors identified in this study.
“All sudden cardiac arrest is not the same,” explained Professor Sumeet Chugh, MD, lead author of the study. “Until now, no prior research has distinguished between potentially treatable sudden cardiac arrest versus untreatable forms that cause death in almost all instances.”
In the US, 300 000 people die due to out-of-hospital sudden cardiac arrest each year. For those affected, 90% will die within 10 minutes of cardiac arrest.
Prevention could have an enormous impact for this largely fatal condition. The biggest challenge, however, lies in distinguishing between those who stand to benefit the most from an implantable cardioverter defibrillator and those who would not.
“Defibrillators are expensive and unnecessary for individuals with the type of sudden cardiac arrest that will not respond to an electrical shock,” said Prof Chugh. “However, for patients with treatable, or ‘shockable,’ forms of the disease, a defibrillator is lifesaving.”
Prof Chugh said that this new research provides a clinical risk assessment algorithm that can better identify patients at highest risk of treatable sudden cardiac arrest—and thus, a better understanding of those patients who would benefit from a defibrillator.
The risk assessment algorithm consists of 13 clinical, electrocardiogram, and echocardiographic variables that could put a patient at higher risk of treatable sudden cardiac arrest.
The risk factors include diabetes, myocardial infarction, atrial fibrillation, stroke, heart failure, chronic obstructive pulmonary disease, seizure disorders, syncope—a temporary loss of consciousness caused by a fall in blood pressure—and four separate indicators found with an electrocardiogram test, including heart rate.
