Effect of Stress-Related Neural Pathways on the Cardiovascular Benefit of Physical Activity

Psychosocial stress and cardiovascular disease

Mahatma Gandhi once famously said: "poverty is the worst type of violence". He was referring to the state of political and social unrest that was pervading his nation, and the impact that humiliating defeat had on those who suffered in dire straits. Today, there is mounting evidence that social disparities cause intense psychosocial stress on those on whom they are imposed and can result in adverse cardiovascular outcomes. In modern society we still witness large disparities in living conditions between races, regions, continents and nations. Even in more privileged nations, we often witness the existence of "food and social deserts" in the middle of large urban centers. Sizable segments of the population are deprived of the comforts and privileges enjoyed by others; food quality and choices are limited, opportunities to exercise and play are scarce or unsafe, physical and verbal violence are prevalent, and racially driven conflicts are frequent. It has become apparent that these conditions predispose to the development of cardiovascular disease and affect its outcome negatively. Besides the increase in incidence of traditional risk factors, such as smoking, hypertension, insulin resistance and obesity, several other pathophysiological mechanisms involving the neuro-endocrine, inflammatory and immune pathways may be responsible for the noted negative outcomes. In this manuscript we review some of the evidence linking social distress with adverse cardiovascular outcomes and the potential subtending mechanisms and therapeutic interventions.

The relation between stress-related neural activity assessed by brain 18F-FDG-PET/CT and cardiovascular outcomes: a systematic review and meta-analysis

PURPOSE

Our study aims to investigate the associations between stress-related neural activity (SNA), a quantified imaging biomarker in processing stress responses assessed by 18F-FDG-PET/CT, and cardiovascular (CV) outcomes based on available evidence.

METHODS

We searched databases from inception to December 1, 2024. Studies assessing the associations between SNA, as quantified by measuring FDG uptake values in the amygdala using 18F-FDG-PET/CT, and CV outcomes were included. Risk of bias was evaluated using the Newcastle-Ottawa Scale. Random-effects model was implemented for pooled effect sizes (ESs) and heterogeneity evaluation.

RESULTS

Ten studies with 3523 patients with 18F-FDG-PET/CT were included in our analysis (mean age: 58.5 years; 48.9% female). The ESs included in the analysis comprised hazard ratios (HR) and standardized mean differences (SMD). Among the studies reporting HR, 192 (11.5%) patients experienced composite adverse CV events during a mean follow-up period of 3.8 years. SNA significantly correlated with an increased risk of composite adverse CV events (pooled adjusted HR: 1.61, 95% confidence interval [CI]: 1.12, 2.32). Among the studies reported SMD, individuals experienced composite adverse CV events had significantly higher SNA values than those who did not (Hedges's g = 0.55, 95% CI: 0.14, 0.96).

CONCLUSIONS

SNA, as a noninvasive quantified indicator of processing stress responses assessed by brain 18F-FDG-PET/CT, is associated with an increased risk of CV outcomes. Further research is warranted to validate these findings and to investigate the clinical utility of SNA across various demographic groups.

Cardiac-Focused Multi-Organ Chips: Advanced Disease Modeling, Drug Testing, and Inter-Organ Communication

Heart disease remains a leading cause of mortality worldwide, posing a significant challenge to global healthcare systems. Traditional animal models and cell culture techniques are instrumental in advancing the understanding of cardiac pathophysiology. However, these methods are limited in their ability to fully replicate the heart's intricate functions. This underscores the need for a deeper investigation into the fundamental mechanisms of heart disease. Notably, cardiac pathology is often influenced by systemic factors, with conditions in other organs contributing to disease onset and progression. Cardiac-focused multi-organ chip technology has emerged to better elucidate these complex inter-organ communications and address the limitations of current in vitro models. This technology offers a novel approach by recreating the cardiac microenvironment and integrating it with other organ systems, thereby enabling more precise disease modeling and drug toxicity assessment. This review provides a comprehensive overview of the heart's structure and function, explores the advancements in cardiac organ chip development, and highlights the applications of cardiac-focused multi-organ chips in medical research. Finally, the future potential of this technology in enhancing disease modeling and therapeutic evaluation is discussed.

Accelerated development of cardiovascular risk factors mediates risk for major adverse cardiovascular events in posttraumatic stress disorder

BACKGROUND

Individuals with posttraumatic stress disorder (PTSD) have high rates of cardiovascular disease (CVD) and increased cardiometabolic CVD risk factors (CVDRFs, e.g., hypertension, hyperlipidemia, or diabetes mellitus). Nevertheless, it remains unknown whether PTSD accelerates CVDRF development and how that impacts the development of major adverse cardiovascular events (MACE) in a broad population. Furthermore, the underlying mechanisms remain incompletely characterized.

OBJECTIVE

We hypothesized that 1) PTSD accelerates CVDRF development, 2) accelerated CVDRF development mediates the PTSD-MACE relationship, and 3) accelerated CVDRF development is partially explained by alterations in neural, autonomic, and inflammatory intermediaries (e.g., stress-associated neural activity [SNA], ventromedial prefrontal cortex [vmPFC] activity, heart rate variability [HRV], and C-reactive protein [CRP]).

METHODS

Subjects (N = 84,343) in the Mass General Brigham Biobank were studied over 10 years. PTSD, CVDRFs, and MACE were identified by diagnostic codes. From participants with available clinical data, neural, autonomic, and inflammatory mediators (e.g., SNA, vmPFC, HRV, and CRP) were assessed.

RESULTS

PTSD independently predicted incident CVDRFs (hazard ratio [95 % confidence interval] = (1.432 [1.287, 1.592], p < 0.001) and associated with the accelerated development of a new CVDRF by ∼ 4 months versus those without PTSD. The development of new CVDRFs predicted incident MACE (1.736 [1.652, 1.823, p < 0.001) and mediated the link between PTSD and MACE (p < 0.05) by up to 36.4 %. Additionally, lower vmPFC activity, lower HRV, and higher CRP were associated with the development of CVDRFs. HRV and CRP significantly mediated the PTSD-CVDRF link.

CONCLUSIONS

The PTSD-MACE link was partially explained by the accelerated development of CVDRFs. Alterations in neural, autonomic, and inflammatory intermediaries contributed to this association. These findings suggest that greater clinical attention to CVDRFs in individuals with PTSD may attenuate MACE risk.

Exercise Training in Heart Failure: Current Evidence and Future Directions

Heart Failure (HF) is a prevalent condition which places a substantial burden on healthcare systems worldwide. Medical management implemented with exercise training (ET) plays a role in prognostic and functional capacity improvement. The aim of this review is to determine the effect of exercise training (ET) on HFpEF and HFrEF patients as well as exercise modality recommendations in frail and sarcopenic subpopulations. Pharmacological therapy structures the cornerstone of management in HF reduced ejection fraction (HFrEF) and aids improved survival rates. Mortality reduction with pharmacological treatments in HF preserved ejection fraction (HFpEF) are yet to be established. Cardiac rehabilitation (CR) and ET can play an important role in both HFrEF and HFpEF. Preliminary findings suggest that CR significantly improves functional capacity, exercise duration, and quality of life. ET has shown beneficial effects on peak oxygen consumption (pVO2) and 6 min walk test distance in HFrEF and HFpEF patients, as well as a reduction in hospitalisation and mortality rates; however, the limited scope of larger trials reporting on this underscores the need for further research. ET also has been shown to have beneficial effects on depression and anxiety levels. High-intensity training (HIT) and moderate continuous training (MCT) have both shown benefits, while resistance exercise training and ventilatory assistance may also be beneficial. ET adherence rates are higher when enrolled to a supervised programme, but prescription rates remain low worldwide. Larger robust trials are required to determine ET's effects on HF, as well as the most efficacious and personalised exercise prescriptions in HF subtypes.

Additive effect of high transportation noise exposure and socioeconomic deprivation on stress-associated neural activity, atherosclerotic inflammation, and cardiovascular disease events

BACKGROUND

Noise exposure and lower socioeconomic status (SES) are both independently linked to increased cardiovascular disease (CVD) risk. Although these factors frequently coexist, their combined impact and the underlying pathophysiological mechanisms remain poorly understood.

OBJECTIVES

This study aimed to evaluate the joint effects of high transportation noise exposure and lower SES on major adverse cardiovascular events (MACE) and the role of the neural-arterial axis in mediating this relationship.

METHODS

We retrospectively analyzed data from 507 individuals who underwent clinical 18F-FDG-PET/CT imaging at a single center. SES was evaluated using local median income (as a primary measure) and area deprivation index (ADI, as a secondary measure). Participants were classified into three groups based on transportation noise exposure and income/ADI: low noise/higher SES, high noise or lower SES, and high noise/lower SES. Cox models assessed MACE risks. Linear regression models evaluated associations with stress-related neural activity (SNA) and arterial inflammation (ArtI).

RESULTS

The combination of high noise exposure and low income (vs. neither exposure) associated with increased MACE risk (HR [95% CI]: 5.597 [2.201-14.233], p < 0.001). SNA (standardized β [95% CI]: 0.389 [0.192-0.586], p < 0.001) and ArtI (0.151 [0.005-0.298], p = 0.043) were greater in this group. Mediation analysis showed that the neural-arterial axis contributes to increased exposure-related MACE risk and accounts for 8% of the overall effect. Similar results were found with ADI.

IMPACT STATEMENT

Our study uniquely demonstrates how combined high transportation noise and lower socioeconomic status additively increases cardiovascular disease risk through specific biological pathways, particularly via effects on stress-associated neural activity and arterial inflammation. As such, the research offers novel insights into the interplay between environmental and socioeconomic factors in cardiovascular health. This underscores an urgent need for integrated public health strategies that address both noise pollution and socioeconomic disparities and provides a foundation for targeted interventions aimed at reducing the burden of cardiovascular disease in vulnerable populations. Central illustration of hypothesized mechanistic pathways linking transportation noise/SES exposure groups and MACE. SNA stress related neural activity (as AmygAc-ratio of amygdala to background cortical activity), MACE major adverse cardiovascular events, ArtI arterial inflammation, ADI Area Deprivation Index, SES socioeconomic status.

Posttraumatic stress disorder increases thrombosis risk: Evidence from a biobank data set

Depression and anxiety are linked to deep venous thrombosis (DVT) and posttraumatic disorder (PTSD) increases risk of venous thromboembolism in women. However, the mechanisms underlying this relationship remain unknown. We hypothesized that PTSD would associate with increased DVT risk, that neuroimmune mechanisms would mediate the PTSD-DVT link, and that these associations would be stronger in women. This cohort study included N = 106 427 participants from a large biobank. PTSD and DVT were defined using ICD-10 codes. A subset (N = 1520) underwent imaging, from which we assessed stress-associated neural activity (SNA). High-sensitivity C-reactive protein (hs-CRP) levels and heart rate variability (HRV) were used as indicators of systemic inflammation and autonomic activity, respectively. Linear, logistic, and Cox regressions and mediation analyses were used to test our hypotheses. Of 106 427 participants, 4192 (3.9%) developed DVT. PTSD associated with increased DVT risk (HR [95% CI]: 1.66 [1.34, 2.07], p < .001), and this finding remained significant after adjustment for age, sex, and traditional DVT risk factors. When analyzed separately by sex, PTSD was significantly associated with DVT risk in women but not men. Further, heightened SNA and lower HRV mediated the effect of PTSD on DVT risk. Results suggest that individuals with PTSD are at increased risk for DVT, and that risk is higher in women. This relationship was partially driven by alterations in stress-associated neural activity and autonomic function, suggesting potential targets for preventive therapies. Future studies are needed to investigate whether intervening on PTSD-DVT mechanisms has downstream beneficial effects on DVT, especially among women.

Neurocardiac Axis Physiology and Clinical Applications

The neurocardiac axis constitutes the neuronal circuits between the arteries, heart, brain, and immune organs (including thymus, spleen, lymph nodes, and mucosal associated lymphoid tissue) that together form the cardiovascular brain circuit. This network allows the individual to maintain homeostasis in a variety of environmental situations. However, in dysfunctional states, such as exposure to environments with chronic stressors and sympathetic activation, this axis can also contribute to the development of atherosclerotic vascular disease as well as other cardiovascular pathologies and it is increasingly being recognized as an integral part of the pathogenesis of cardiovascular disease. This review article focuses on 1) the normal functioning of the neurocardiac axis; 2) pathophysiology of the neurocardiac axis; 3) clinical implications of this axis in hypertension, atherosclerotic disease, and heart failure with an update on treatments under investigation; and 4) quantification methods in research and clinical practice to measure components of the axis and future research areas.

Anxiety and Depression Associated With Increased Cardiovascular Disease Risk Through Accelerated Development of Risk Factors

Background

Prior studies have incompletely assessed whether the development of cardiometabolic risk factors (CVDRF) (hypertension, hyperlipidemia, and diabetes mellitus) mediates the association between anxiety and depression (anxiety/depression) and cardiovascular disease (CVD).

Objectives

The authors aimed to evaluate the following: 1) the association between anxiety/depression and incident CVDRFs and whether this association mediates the increased CVD risk; and 2) whether neuro-immune mechanisms and age and sex effects may be involved.

Methods

Using a retrospective cohort design, Mass General Brigham Biobank subjects were followed for 10 years. Presence and timing of anxiety/depression, CVDRFs, and CVD were determined using ICD codes. Stress-related neural activity, chronic inflammation, and autonomic function were measured by the assessment of amygdalar-to-cortical activity ratio, high-sensitivity CRP, and heart rate variability. Multivariable regression and mediation analyses were employed.

Results

Among 71,214 subjects (median age 49.6 years; 55.3% female), 27,048 (38.0%) developed CVDRFs during follow-up. Pre-existing anxiety/depression associated with increased risk of incident CVDRF (OR: 1.71 [95% CI: 1.59-1.83], P < 0.001) and with a shorter time to their development (β = -0.486 [95% CI: -0.62 to -0.35], P < 0.001). The development of CVDRFs mediated the association between anxiety/depression and CVD events (log-odds: 0.044 [95% CI: 0.034-0.055], P < 0.05). Neuro-immune pathways contributed to the development of CVDRFs (P < 0.05 each) and significant age and sex effects were noted: younger women experienced the greatest acceleration in the development of CVDRFs after anxiety/depression.

Conclusions

Anxiety/depression accelerate the development of CVDRFs. This association appears to be most notable among younger women and may be mediated by stress-related neuro-immune pathways. Evaluations of tailored preventive measures for individuals with anxiety/depression are needed to reduce CVD risk.

Heart-brain axis: Pushing the boundaries of cardiovascular molecular imaging

Despite decades of research, the heart-brain axis continues to challenge investigators seeking to unravel its complex pathobiology. Strong epidemiologic evidence supports a link by which insult or injury to one of the organs increases the risk of pathology in the other. The putative pathways have important differences between sexes and include alterations in autonomic function, metabolism, inflammation, and neurohormonal mechanisms that participate in crosstalk between the heart and brain and contribute to vascular changes, the development of shared risk factors, and oxidative stress. Recently, given its unique ability to characterize biological processes in multiple tissues simultaneously, molecular imaging has yielded important insights into the interplay of these organ systems under conditions of stress and disease. Yet, additional research is needed to probe further into the mechanisms underlying the heart-brain axis and to evaluate the impact of targeted interventions.