Tag: Cardiology

Breakthrough $20 million OCT project aims to revolutionize eye health screening
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In the United States, more than one-fourth of adults over age 40 have an eye disease, including glaucoma, cataracts or age-related macular degeneration, or a chronic health condition that affects the eyes, such as diabetic retinopathy. These conditions are a strain on an individual’s health as well as on the health-care system, yet early diagnosis and management can help to prevent more than 90% of severe vision loss.

Chao Zhou, a professor of biomedical engineering in the McKelvey School of Engineering at Washington University in St. Louis, has been working to improve optical coherence tomography (OCT) systems that can conduct high-resolution imaging of the eyes. Now, with an up to $20 million contract from the Advanced Research Projects Agency for Health (ARPA-H), he plans to create a portable OCT system based on photonic integrated circuits (PIC) and custom-designed electronic integrated circuits that could offer advanced eye screening to many more patients and at a lower cost. The technology also could be used in other applications, such as cardiology, dermatology, dentistry, endoscopy and urology.

The contract is part of ARPA-H’s first call for proposals for unconventional approaches to improving health outcomes across patient populations, communities, diseases and health conditions through breakthrough research and technological advancements. It is the first ARPA-H contract awarded to Washington University.

Traditional OCT systems are expensive, complex, bulky and labor-intensive to assemble and calibrate. The proposed system would weigh a few pounds, take high-resolution 3D scans of the retina in less than a second and be a fraction of the cost of the traditional systems.

The integration of photonic and electronic integrated circuits simplifies the assembly process and lowers production costs, making OCT more accessible to a wider range of health-care facilities and patients. Integrating components on a photonic chip also enhances overall stability and robustness, making these systems less susceptible to environmental influences and wear and tear, ensuring a longer lifespan and lower maintenance costs.”

Chao Zhou, professor of biomedical engineering, McKelvey School of Engineering, Washington University in St. Louis

Zhou’s group invented the space-division multiplexing optical coherence tomography (SDM-OCT), a technique that takes multiple high-definition OCT images simultaneously with a single detector and is at least 10 times faster than existing OCT scanners, which creates fewer opportunities for errors from patient movement. However, these systems required extensive time and labor to assemble components for each channel, which limited their broad use.

With the ARPA-H funding, Zhou and collaborators will assemble the components in a photonic chip using advancements in complementary metal-oxide-semiconductor (CMOS) processes used in the semiconductor industry. This will streamline manufacturing and lower costs. Once functioning, they will conduct studies using the device on adult and pediatric patients.

Developing a fully integrated photonic-integrated chip (PIC)-OCT system is very impactful yet also very challenging, the researchers said, so the team has divided its work into eight parts, ranging from developing components to testing. At the end of the five-year project, the team expects to have developed photonic and electronic chips and portable PIC-OCT prototypes specifically for ophthalmic imaging.

The proposed system is more than 50 times faster than existing state-of-the-art commercial OCT systems at a fraction of the cost, the researchers said. By optimizing and integrating the photonic and electronic circuits, the researchers can create an integrated image acquisition and signal processing engine with benefits that extend into other areas of health care, such as glucose sensing and portable skin imagers.

Collaborating with Zhou are:
- Shu-Wei Huang, an assistant professor of electrical, computer and energy engineering and of biomedical engineering at the University of Colorado Boulder;
- Aravind Nagulu, an assistant professor of electrical and systems engineering at the McKelvey School of Engineering;
- Rithwick Rajagopal, MD, PhD, an associate professor of ophthalmology and visual sciences at Washington University School of Medicine;
- Margaret Reynolds, MD, an assistant professor of ophthalmology and visual sciences at Washington University School of Medicine; and
- Lan Yang, the Edwin H. & Florence G. Skinner Professor of electrical and systems engineering at the McKelvey School of Engineering.
Yang said it is in her long-term interest to transform knowledge in photonics research into technologies and tangible products with a far-reaching societal impact, with health-care applications at the top of her agenda.

“I’m excited to be part of this multidisciplinary team that aims to develop a new OCT system with capabilities and features enabled by advancements in nanofabrication processes for optoelectronic devices driven by various industries, from telecommunication to data centers and consumer electronics,” Yang said. “Our proposed portable OCT system, based on photonic integrated circuits (PIC), will provide advanced and cost-effective eye screening and extend its benefits to other medical fields.”

Rajagopal said that eye doctors have benefitted from the diagnostic insights offered by OCT technology for the past 15 years, but the systems are limited by scan-speed and field-of-view.

Most modern scanners can only image the very center of the retina -; the macula -; and require cooperative patients who have the mobility to maneuver into and stay steady on a desktop system for at least 30-60 seconds (or more), Rajagopal said.

“I am enthusiastic about the potential clinical benefits offered by Dr. Zhou’s new system, as it may allow us to perform much higher-resolution scans and include simultaneous peripheral scanning in addition to the retinal center, all while taking a fraction of the time required by currently available systems,” Rajagopal said. “We may therefore be able to scan patients who are unable to cooperate for traditional ocular imaging, including young children and adults with disabilities, without the need for pupillary dilation or sedated exams.”

The team will work with commercial foundries to fabricate the photonic and electronic integrated circuits.

“Not only does this fully integrated PIC-OCT system outperform conventional OCT systems, but it also boasts excellent manufacturability and robustness and reduces device footprint,” Zhou said. “In addition, mass production would significantly reduce manufacturing costs, paving the way for widespread future dissemination.”

While the team already has several U.S. and international patents related to the SDM-OCT, it is working with Washington University’s Office of Technology Management on patent applications for the improved design. They will also work with ARPA-H Project Accelerator Transition Innovation Office and with the Food & Drug Administration on regulatory considerations to clear the pathway for future clinical translation.

“I am very excited to be part of this world-class team to pursue this ambitious project that makes OCT a true point-of-care solution,” Huang said. “It is a perfect example showing how PIC technology can be transformative in areas other than communication and computing.”

Source:

Washington University in St. Louis
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February 14, 2024
Mediterranean and vegetarian diets boost heart health by improving novel CVD markers

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In a recent study published in the journal Nutrition & Metabolism, researchers evaluated the impact of the lacto-ovo vegetarian diet (VD) and Mediterranean diet (MD) on apolipoprotein levels and cardiovascular disease (CVD) risk factors among low-moderate-risk individuals.

CVD is the leading cause of global mortality, necessitating the development of novel biomarkers for prevention, early diagnosis, and treatment. Apoproteins, which regulate lipoprotein metabolism, are considered a risk marker for CVD. The European Society of Cardiology (ESC) recommends ApoB as a CVD risk marker. ApoA-I, mainly found in high-density lipoprotein (HDL) lipids, play protective roles in reverse cholesterol transport. However, data on diet’s influence on apolipoproteins is limited.

Study: Effects of a dietary intervention with lacto-ovo-vegetarian and Mediterranean diets on apolipoproteins and inflammatory cytokines: results from the CARDIVEG study. Image Credit: Brian A Jackson / Shutterstock

About the study

In the present study, researchers assessed the influences of MD and VD diets on circulating apolipoproteins and their association with cardiovascular disease risk estimators, such as inflammatory cytokine levels and lipid profiles.

The study included 52 participants (39 women; mean age of 49 years) in the Cardiovascular Prevention with Vegetarian (CARDIVEG) diet randomized, crossover clinical trial. All individuals were at low-moderate CVD risk (<5.0% at ten years, using the ESC guidelines) and selected from the Clinical Nutrition Department of Careggi Hospital, Italy.

Eligibility individuals were overweight or obese with body mass index (BMI) ≥25 kg/m2 and ≥1.0 cardiovascular disease risk factors: low-density lipoprotein (LDL) beyond 115 mg dL^-1; triglyceride levels above 150 mg dL^-1; total cholesterol above 190 g/dL; and fasting blood glucose ranging from 110 to 125.0 mg dL^-1. The researchers excluded individuals with unstable medical conditions, medication prescriptions, expecting or breastfeeding women, and those who consumed poultry, fish, meat, or meat products or participated in weight loss programs in the previous six months.

The participants followed the MD (27 individuals) and VD (25 individuals) diets for three months. Both diets comprised 50% to 55% carbohydrates, 15% to 20% proteins, and 25% to 30% total fats (≤7.0% of saturated fat, less than 300 milligrams of cholesterol). The team provided the participants with one-week menu plans, different recipes, and precise data on foods to consume and avoid.

The primary outcomes were changes in body weight, fat mass, and BMI, and the secondary outcomes included changes in circulating CVD risk markers and apolipoprotein levels. The team obtained medical history, demographics, comorbidities, risk factors, lifestyle, and dietary data at study initiation. They collected blood samples with body composition and BMI data before and after the interventions.

The team used the Medi-Lite and National Health and Nutrition Examination Survey (NHANES) questionnaires to assess adherence to MD and VD diets, respectively. They conducted a primary analysis using general linear modeling, evaluating differences in apolipoprotein levels by sex, age, and CVD risk factors. They used linear regressions to examine the association between these changes and lipid profiles, inflammatory profiles, and dietary components.

Results

MD and VD improved lipid profiles and anthropometric variables, reducing total energy, fats, and cholesterol and increasing total carbohydrates. VD lowered protein and increased dietary fiber, while MD decreased body weight, fat mass, and BMI. VD also reduces fat-free body mass. VD reduced LDL by 5.0%, while MD reduced serum triglycerides by 9.0%. Both diets lowered inflammatory parameters, with MD significantly decreasing interleukin-10 by 37% and interleukin-17 by 49%.

Both diets reduced inflammatory parameters, with significantly higher (24%) ApoC-I levels after VD. Both diets increased ApoA-I (2.7% by VD and 6.1% by MD), ApoC-I (24% by VD and 11% by MD), and ApoD (6.5% by VD and 6.2% by MD) levels. However, ApoB/ApoA-I ratios reduced by 1.9% and 7.4% after VD and MD, respectively. Conversely, the team observed opposite trends for ApoB (+0.7% by VD and −1.6% by MD), ApoC-III (−5.6% by VD and +1.8% by MD), and ApoE (+14% by VD and −1.6% by MD).

The team found negative correlations between apolipoprotein C-III and carbohydrates after MD and between ApoD levels and saturated fats after VD. In contrast, they found positive correlations between HDL and ApoD after VD and between serum triglycerides, ApoCI, and ApoD after MD. IL-17 positively correlated with ApoB and ApoC-III after VD. However, they found significant negative correlations between ApoC-III and carbohydrate percentage after MD and between ApoD and saturated fat percentage after VD. Serum triglycerides showed positive correlations with ApoC-I and ApoD levels after MD.

HDL changes positively correlated with ApoD levels after VD. Linear regressions confirmed the results, adjusted for potential confounders such as weight change and the treatment order. The subgroup analyses showed that both diets positively influenced circulating apolipoproteins, especially in women aged ≥50 years with less than three cardiovascular disease risk factors.

The study findings showed that VD and MD improve cardiovascular disease risk in low-moderate CVD-risk individuals by regulating lipid and inflammatory profiles. MD more positively affects apolipoprotein levels, especially in women, individuals aged >50 years, and those with one or two CVD risk factors. The study also found differences in associations between apolipoprotein levels and specific nutrients, with an unexpected inverse association between carbohydrate intake and ApoC-III after MD.

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February 14, 2024
Bariatric surgery more effective in controlling hypertension rates in obese patients

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Bariatric surgery is more effective in controlling hypertension rates, or high blood pressure, in people with obesity and uncontrolled high blood pressure compared to blood pressure medication alone, according to a study published today in the Journal of the American College of Cardiology. People who underwent bariatric surgery had lower BMI and were on fewer medications after five years while maintaining normal blood pressure levels than those who only used antihypertensive medications.

According to the CDC, the U.S. obesity and hypertension rates in adults are 41.9% and 45.4%, respectively. Obesity is a known risk factor for cardiovascular disease and a major contributor to high blood pressure, which can make a person more susceptible to heart attack, stroke and heart failure, among other risks.

In clinical practice, obesity is an overlooked condition. As a consequence, there is a frequent failure in approaching obesity as a crucial step for mitigating the risk of important cardiovascular risk factors including hypertension.”

Carlos Aurelio Schiavon, MD, FACS, lead author of the study and a surgeon specializing in bariatric surgery at Heart Hospital (hcor) and BP Hospital in Sao Paulo

Researchers in this study looked at the impact of treating obesity to lower high blood pressure. While there are new medications to treat obesity, long-term adherence to medication can be challenging. This study looks at bariatric surgery as a better long-term solution to control obesity and, as a result, high blood pressure.

The GATEWAY trial included 100 people (76% of which were female) who had a body mass index (BMI) of around 36.9Kg/m². All participants had hypertension and were using at least two medications. People with previous cardiovascular events and poorly controlled Type 2 diabetes were excluded. Subjects were assigned to either Roux-en-Y gastric bypass with medical therapy or medial therapy alone and the primary outcome was reduction of at least 30% antihypertensive medications while maintaining blood pressure levels less than 140/90 mmHg at five years.

At five years, BMI was 28.01 Kg/m²for those who received bariatric surgery and 36.40 Kg/m²for those on medical therapy alone. People who had bariatric surgery had an 80.7% reduction in the number of medications they were taking compared to a 13.7% reduction in those only using medical therapy. Hypertension remission, defined as controlled blood pressure without medications, was 46.9% in those who underwent bariatric surgery compared to 2.4% in those on medical therapy alone.

“Our results underscore the importance of approaching obesity in reducing hypertension rates,” Schiavon said.

Limitations of the study include that it was a single-center, open-label study with a small sample size and there was loss of follow up in some patients.

In an accompanying editorial comment, Michael Hall, MD, MSc, professor and chair of the Department of Medicine at the University of Mississippi Medical Center, said the study provides important long-term data on the benefits of gastric bypass on weight loss and blood pressure control, but questions remain.

“Further studies assessing the threshold for bariatric surgery in people with obesity, optimal timing of bariatric surgery in obese people with cardiometabolic diseases, type of bariatric surgery and comparative studies of obesity pharmacotherapies and bariatric surgery are needed to clarify the optimal treatment pathways for this common and growing disease,” he said.

Source:

American College of Cardiology

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February 6, 2024
CT scans may be better first step for evaluating chest pain

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Previous studies have found less than 40% of patients with stable chest pain undergoing invasive coronary angiography are found to have obstructive coronary artery disease. Recent randomized clinical trials have demonstrated a benefit to using computed tomography angiography (CTA) first in evaluation of these patients, and a new study being presented at the American College of Cardiology Cardiovascular Summit lends credence to this strategy, finding that CT was associated with a higher likelihood of revascularization compared to other imaging modalities or no testing.

Stable angina is a type of chest discomfort that occurs when the heart muscle needs more oxygen than usual-;such as during stress, exercise or cold weather-;but it’s not getting it, often due to blocked coronary arteries. Patients with stable angina are often treated with guideline-directed medical therapy and lifestyle changes but may also need a coronary revascularization procedure to restore adequate blood flow to resolve their symptoms.

Right now, when a patient presents to their primary care physician or cardiologist with symptoms suspicious for angina, they are commonly referred for additional testing.”

Markus Scherer, MD, Director of Cardiac CT and Structural Heart Imaging at Atrium Health-Sanger Heart & Vascular Institute and study’s senior author

Between October 2022 and June 2023, researchers at Atrium Health-Sanger Heart & Vascular Institute in Charlotte, North Carolina, assessed 786 patients who had no prior diagnosis of coronary artery disease and underwent elective invasive coronary angiography (ICA) for the evaluation of suspected angina. The pre-ICA testing strategies were: no noninvasive testing with direct referral to ICA (44%), stress echocardiogram (3%), stress myocardial perfusion imaging (15%), stress MRI (2%) and coronary CTA (36%). The study cohort had a mean age of 66 years, was 63% male, 37% female, 81% White, 13% Black, 1% Asian, 1% Hispanic and 1% other.

The researchers compared rates of subsequent revascularization between patients whose initial evaluation was coronary CTA versus stress testing or clinical judgement (no testing). The “CT first” strategy was associated with subsequent revascularization in 62% of patients compared to 34% for the combination of other modalities or direct ICA referral.

The 2021 AHA/ACC Guideline for the Evaluation and Diagnosis of Chest Pain suggests either non-invasive functional imaging or coronary CTA as the initial test without specifying a preference for one or the other.

According to the researchers, there are a multitude of reasons health systems don’t currently use a CT first approach, including the availability of high-quality CT scanners; availability of qualified cardiac CT interpreting physicians; and challenges in transitioning to a newer approach after decades of pre-established patterns (i.e. stress testing). Furthermore, a CT first approach is predominately advocated for patients with unestablished coronary artery disease and does not apply to all, as some patient factors may reduce the accuracy and utility of coronary CTA.

“While care must be individualized, for patients with unknown or unestablished coronary artery disease, the transition to a ‘CT first’ strategy should be a high priority for cardiovascular care providers,” Scherer said. “The non-invasive approach has a lower risk and cost than a diagnostic heart catheterization and, for the CT approach-;but not stress testing-;provides information on the absence, presence and extent of coronary atherosclerosis and whether or not there are high risk plaques as well as vessel blockages, which helps streamline patient management and risk reduction.”

Since coronary CTA is less expensive than both nuclear myocardial perfusion imaging and ICA, there is a direct cost saving to patients and third-party payers with the CT first approach, according to Scherer. From the perspective of a health system, the most financially efficient evaluation approach becomes more important during the transition to a value-oriented health care system.

According to the authors, the study demonstrates “real world” credence to the randomized trials showing similar benefits to a “CT first” strategy and should promote increased adoption of this strategy for the evaluation of patients with chest pain and an unestablished history of coronary artery disease.

“Cardiac catheterization labs are a capital and human resource intensive care environment. Using them for their maximum potential of treating disease, rather than diagnosing it, bring the highest yield for these resources to the health care system,” Scherer said.

The full results of the study and other studies will be presented at the ACC Cardiovascular Summit 2024 in Washington, on February 1-3, 2024. The ACC Cardiovascular Summit 2024 will examine innovative strategies and emerging trends in CV care, assess operational efficiencies to enhance the effectiveness of the CV service line, and adopt customizable approaches that support economic sustainability.

Source:

American College of Cardiology

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February 1, 2024
Machine learning could personalize diuretic treatment for patients with acute decompensated heart failure

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A recent study co-authored by Dr. Matthew Segar, a third-year cardiovascular disease fellow at The Texas Heart Institute and led by his research and residency mentor, University of Texas Southwestern Medical Center’s Dr. Ambarish Pandey, utilized a machine learning-based approach to identify, understand, and predict diuretic responsiveness in patients with acute decompensated heart failure (ADHF).

The study “A Phenomapping Tool and Clinical Score to Identify Low Diuretic Efficiency in Acute Decompensated Heart Failure,” published in the prestigious Journal of American College Cardiology Heart Failure (JACC Heart Failure), leverages decades of clinical and registry datasets funded by the National Institutes of Health and American Heart Association.

The researchers leveraged machine-learning-based approaches to develop a prediction tool called the BAN-ADHF score, which showed promising results in accurately predicting diuretic response. After validation in other clinical populations, implementing this tool could potentially lead to personalized strategies for effectively managing the congestion of patients hospitalized with ADHF.

There remains a lack of agreement among experts regarding the most effective approach to address diuretic resistance in patients with heart failure who are stable hemodynamically and have an excess volume of fluid. It is generally recommended to optimize the dosage of loop diuretics before considering combination therapy; however, there is no consensus on how much the dosage should be increased before introducing another diuretic.

“Inefficient diuretic response in hospitalized patients can hinder treatment progress and increase the risk of post-discharge rehospitalization and mortality. It’s crucial to identify individuals with low diuretic efficiency early on to tailor decongestion strategies and improve clinical outcomes,” according to Dr. Segar.

ADHF is a public health issue that is becoming increasingly concerning. The disease results in emergency room visits, hospital admissions, and associated high healthcare costs. ADHF is characterized by the body having too much fluid, which often requires hospitalization or changing a patient’s current treatment plan.

Today, a primary goal of treating ADHF is to relieve congestion using loop diuretic drugs. However, there is still uncertainty about the best dose of these agents to administer. Additionally, because of the heterogeneity of ADHF patients, a more personalized approach to predicting optimal dosing strategies is needed.”

Dr. Joseph G. Rogers, President and CEO of The Texas Heart Institute

In the study, researchers from institutions across the United States utilized machine learning (ML) algorithms to identify subgroups of patients with acute heart failure based on their responsiveness to diuretic therapy. Specifically, the researchers developed a diuretic efficiency phenomapping approach for patients with ADHF by using publicly available and deidentified data from several clinical trials and registries, including DOSE, ROSE-AHF, CARRESS-HF, ATHENA-HF, ESCAPE, and the American Heart Association Precision Medicine Platform Get with the Guidelines-HF (GWTG-HF) registry. This participant-level pooled data enabled the investigators to develop a phenomapping approach and diuretic efficiency score. The patients within each subgroup shared similar characteristics but were clinically distinct from other subgroups, particularly in their response to diuretic therapy. In addition to differences in their diuretic response, the patient subgroups also had meaningfully different clinical outcomes, highlighting the prognostic utility of the phenogrouping approach. The investigators subsequently developed and validated the BAN-ADHF score to predict the probability of being in the phenogroup with the least diuretic response.

“We know the BAN-ADHF score can accurately identify, characterize, and predict diuretic resistance among individuals with ADHF mathematically. Now we must take this medical knowledge and conduct a clinical study to evaluate whether implementing the BAN-ADHF score in our care protocols improves outcomes for patients hospitalized with acute decompensated heart failure,” shared Dr. Segar.

Notably, the work described in this study received recognition from the National Institutes of Health’s National Heart, Lung, and Blood Institute (NHLBI) as a winning solution to the NHLBI Big Data Analysis Challenge: Creating New Paradigms for Heart Failure Research. The challenge encouraged the development of novel, open-source disease models to define subgroups of heart failure and support further advancements in managing the disease. Additionally, Dr. Segar received the American Heart Association’s Samuel A. Levine Early Career Clinical Investigator Award for his role in developing the phenomapping tool and the diuretic resistance clinical risk score. As part of the honor, he presented his research on “Development and Validation of a Phenomapping Tool To Identify Patients With Diuretic Resistance in Acute Decompensated Heart Failure: A Multi-Cohort Analysis” at the American Heart Association’s 2022 Scientific Sessions.

Study collaborators included investigators from The Texas Heart Institute, Duke University School of Medicine, Cleveland Clinic, Houston Methodist DeBakey Heart and Vascular Center, University of Mississippi Medical Center, Baylor Scott and White Research Institute, St. Vincent Heart Center, The University of Texas Southwestern Medical Center, Ronald Reagan UCLA Medical Center, Institute for Precision Cardiovascular Medicine at the American Heart Association, Stony Brook University School of Medicine, Northwestern University School of Medicine, and University of Colorado.

Source:

Journal reference:

Segar, M. W., et al. (2023). A Phenomapping Tool and Clinical Score to Identify Low Diuretic Efficiency in Acute Decompensated Heart Failure. JACC: Heart Failure. doi.org/10.1016/j.jchf.2023.09.029.

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January 31, 2024