Acute psychological stress-induced progenitor cell mobilization and cardiovascular events

OBJECTIVE

Certain brain activation responses to psychological stress are associated with worse outcomes in CVD patients. We hypothesized that elevated acute psychological stress, manifesting as greater activity within neural centers for emotional regulation, mobilizes CPC from the bone marrow to the peripheral blood and predicts future cardiovascular events.

METHODS

In 427 patients with stable CAD undergoing a laboratory-based mental stress (MS) test, CPCs were enumerated using flow cytometry as CD34-expressing mononuclear cells (CD34+) before and 45 min after stress. Changes in brain regional blood flow with MS were measured using high resolution-positron emission tomography (HR-PET). Association between the change in CPC with MS and the risk of cardiovascular death or myocardial infarction (MI) during a 5-year follow-up period was analyzed.

RESULTS

MS increased CPC counts by a mean of 150 [630] cells/mL (15%), P < 0.001. Greater limbic lobe activity, indicative of activation of emotion-regulating centers, was associated with greater CPC mobilization (P < 0.005). Using Fine and Gray models after adjustment for demographioc, clinical risk factors and medications use, greater CPC mobilization was associated with a higher adjusted risk of adverse events; a rise of 1000 cells/mL was associated with a 50% higher risk of cardiovascular death/MI [hazards ratio, 1.5, 95% confidence interval, 1.1-2.2).

CONCLUSION

Greater limbic lobe activity, brain areas involved in emotional regulation, is associated with MS-induced CPC mobilization. This mobilization isindependently associated with cardiovascular events. These findings provide novel insights into mechanisms through which psychological stressors modulate cardiovascular risk.

Generative Artificial Intelligence for Chest Radiograph Interpretation in the Emergency Department

Importance

Multimodal generative artificial intelligence (AI) methodologies have the potential to optimize emergency department care by producing draft radiology reports from input images.

Objective

To evaluate the accuracy and quality of AI-generated chest radiograph interpretations in the emergency department setting.

Design, Setting, and Participants

This was a retrospective diagnostic study of 500 randomly sampled emergency department encounters at a tertiary care institution including chest radiographs interpreted by both a teleradiology service and on-site attending radiologist from January 2022 to January 2023. An AI interpretation was generated for each radiograph. The 3 radiograph interpretations were each rated in duplicate by 6 emergency department physicians using a 5-point Likert scale.

Main Outcomes and Measures

The primary outcome was any difference in Likert scores between radiologist, AI, and teleradiology reports, using a cumulative link mixed model. Secondary analyses compared the probability of each report type containing no clinically significant discrepancy with further stratification by finding presence, using a logistic mixed-effects model. Physician comments on discrepancies were recorded.

Results

A total of 500 ED studies were included from 500 unique patients with a mean (SD) age of 53.3 (21.6) years; 282 patients (56.4%) were female. There was a significant association of report type with ratings, with post hoc tests revealing significantly greater scores for AI (mean [SE] score, 3.22 [0.34]; P < .001) and radiologist (mean [SE] score, 3.34 [0.34]; P < .001) reports compared with teleradiology (mean [SE] score, 2.74 [0.34]) reports. AI and radiologist reports were not significantly different. On secondary analysis, there was no difference in the probability of no clinically significant discrepancy between the 3 report types. Further stratification of reports by presence of cardiomegaly, pulmonary edema, pleural effusion, infiltrate, pneumothorax, and support devices also yielded no difference in the probability of containing no clinically significant discrepancy between the report types.

Conclusions and Relevance

In a representative sample of emergency department chest radiographs, results suggest that the generative AI model produced reports of similar clinical accuracy and textual quality to radiologist reports while providing higher textual quality than teleradiologist reports. Implementation of the model in the clinical workflow could enable timely alerts to life-threatening pathology while aiding imaging interpretation and documentation.

Child Maltreatment and Inflammatory Response to Mental Stress Among Adults Who Have Survived a Myocardial Infarction

OBJECTIVE

Experiences of child maltreatment are associated with cardiovascular risk and disease in adulthood; however, the mechanisms underlying these associations are poorly understood.

METHODS

We examined associations between retrospectively self-reported exposure to child maltreatment (Early Trauma Inventory Self-Report Short Form) and inflammatory responses to mental stress among adults (mean age = 50 years) who recently had a myocardial infarction ( n = 227). Inflammation was assessed as blood interleukin-6 (IL-6), matrix metalloproteinase-9 (MMP-9), and monocyte chemoattractant protein-1 concentrations, measured before and after a standardized public speaking stress task. We used mixed linear regression models adjusting for cardiovascular disease severity, medication usage, and psychosocial, demographic, and life-style factors.

RESULTS

In women, increases in IL-6 levels and MMP-9 levels with stress were smaller in those exposed to sexual abuse, relative to those unexposed (IL-6 geometric mean increases = 1.6 [95% confidence interval {CI} = 1.4-1.9] pg/ml versus 2.1 [95% CI = 1.8-2.4] pg/ml; MMP-9 geometric mean increases = 1.0 [95% CI = 0.9-1.2] ng/ml versus 1.2 [95% CI = 1.1-1.4] ng/ml). No differences were noted for emotional or physical abuse. By contrast in men, individuals exposed to sexual abuse had larger IL-6 responses than those not exposed to abuse.

CONCLUSIONS

These findings suggest sex differences in stress response among survivors of a myocardial infarction exposed to abuse early in life. They also underscore the importance of examining sex as an effect modifier of relationships between exposure to early life adversity and inflammatory responses to mental stressors in midlife.

Early Life Trauma Is Associated With Increased Microvolt T-Wave Alternans During Mental Stress Challenge: A Substudy of Mental Stress Ischemia: Prognosis and Genetic Influences

Background

Early life trauma has been associated with increased cardiovascular risk, but the arrhythmic implications are unclear. We hypothesized that in patients with coronary artery disease, early life trauma predicts increased arrhythmic risk during mental stress, measured by elevated microvolt T‐wave alternans (TWA), a measure of repolarization heterogeneity and sudden cardiac death risk.

Methods and Results

In a cohort with stable coronary artery disease (NCT04123197), we examined early life trauma with the Early Trauma Inventory Self Report‐Short Form. Participants underwent a laboratory‐based mental stress speech task with Holter monitoring, as well as a structured psychiatric interview. We measured TWA during rest, mental stress, and recovery with ambulatory electrocardiographic monitoring. We adjusted for sociodemographic factors, cardiac history, psychiatric comorbidity, and hemodynamic stress reactivity with multivariable linear regression models. We examined 320 participants with noise‐ and arrhythmia‐free ECGs. The mean (SD) age was 63.8 (8.7) years, 27% were women, and 27% reported significant childhood trauma (Early Trauma Inventory Self Report‐Short Form ≥10). High childhood trauma was associated with a multivariable‐adjusted 17% increase in TWA (P=0.04) during stress, and each unit increase in the Early Trauma Inventory Self Report‐Short Form total score was associated with a 1.7% higher stress TWA (P=0.02). The largest effect sizes were found with the emotional trauma subtype.

Conclusions

In a cohort with stable coronary artery disease, early life trauma, and in particular emotional trauma, is associated with increased TWA, a marker of increased arrhythmic risk, during mental stress. This association suggests that early trauma exposures may affect long‐term sudden cardiac death risk during emotional triggers, although more studies are warranted.

Association of Early-Life Trauma and Risk of Adverse Cardiovascular Outcomes in Young and Middle-aged Individuals With a History of Myocardial Infarction

IMPORTANCE

Compared with older patients, young adults with a history of myocardial infarction (MI) tend to have a higher burden of psychosocial adversity. Exposure to early-life stressors may contribute to the risk of adverse outcomes in this patient population, potentially through inflammatory pathways.

OBJECTIVE

To investigate the association of early-life trauma with adverse events and examine whether inflammation plays a role.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients aged 18 to 60 years with a verified history of MI in the past 8 months from a university-affiliated hospital network. Baseline data were collected from June 2011 to March 2016, and follow-up data were obtained through July 2019. Analysis began September 2019.

EXPOSURES

Early-life trauma was assessed using the Early Trauma Inventory-Self Report short form (ETI-SR-SF), both as a continuous and as a binary variable at the threshold of a score of 7 or higher. Inflammatory biomarkers, interleukin 6, and C-reactive protein were obtained at baseline.

MAIN OUTCOMES AND MEASURES

A composite end point of recurrent MI, stroke, heart failure hospitalization, and cardiovascular death over a median 3-year follow-up.

RESULTS

Of 300 patients, the mean (SD) age was 51 (7) years, 198 (66%) were African American, and 150 (50%) were women. Compared with participants with MI with an ETI-SR-SF score less than 7, those with a score of 7 or higher had higher levels of interleukin 6 and C-reactive protein at baseline. Compared with participants with an ETI-SR-SF score less than 7, those with a score of 7 or higher were at a greater risk for adverse outcomes, with a hazards ratio of 2.3 (95% CI, 1.3-3.9). Results remained consistent in multivariable analysis. Further adjustment for C-reactive protein rendered the results no longer statistically significant. Early-life trauma displayed a dose-dependent response when analyzed as a continuous variable and by quartiles.

CONCLUSIONS AND RELEVANCE

Early-life trauma is an independent risk factor for adverse outcomes in young and middle-aged individuals with a history of MI. Neurobiological mechanisms leading to lifetime activation of systemic inflammatory cascades may be implicated.

Brain correlates of stress-induced peripheral vasoconstriction in patients with cardiovascular disease

The influence of acute psychological stress on cardiovascular disease is an emerging public health concern. Identification of brain mechanisms underlying this may aid in the discovery of possible treatments. Acute psychological stress may induce arteriolar vasoconstriction and reduce blood flow to vital organs. We hypothesized that functional changes in brain regions involved with memory and autonomic/emotional regulation are implicated in the vasoconstrictive stress response, including the medial prefrontal cortex (anterior cingulate), insula, and dorsolateral prefrontal cortex. Subjects with a history of coronary artery disease (N = 59) underwent measurement of microvascular vasomotor tone with the EndoPAT device and O-15 positron emission tomography (PET) imaging of the brain during exposure to mental stress and control conditions. The peripheral arterial tonometry (PAT) ratio was calculated as the mean peripheral vasomotor tone during stress divided by the mean tone during rest. Whole brain contrasts were performed between groups above and below the median PAT ratio, and significant contrasts were defined with cutoff p < 0.005. Stress-induced peripheral vasoconstriction (below median PAT ratio) was associated with increased stress activation in insula and parietal cortex, and decreased activation in the medial prefrontal cortex with stress tasks compared to control tasks. These findings demonstrate that stress-induced vasoreactivity is associated with changes in brain responses to stress in areas involved in emotion and autonomic regulation. These findings have important implications on possible treatments for mental stress-induced vascular toxicity.

The effects of a moisture-wicking fabric shirt on the physiological and perceptual responses during acute exercise in the heat

This study investigated the effects that a form fitted, moisture-wicking fabric shirt, promoted to have improved evaporative and ventilation properties, has on the physiological and perceptual responses during exercise in the heat. Ten healthy male participants completed two heat stress tests consisting of 45 min of exercise (50% VO2peak) in a hot environment (33 °C, 60% RH). One heat stress test was conducted with the participant wearing a 100% cotton short sleeved t-shirt and the other heat stress test was conducted with the participant wearing a short sleeved synthetic shirt (81% polyester and 19% elastane). Rectal temperature was significantly lower (P < 0.05) in the synthetic condition during the last 15 min of exercise. Furthermore, the synthetic polyester shirt retained less sweat (P < 0.05). As exercise duration increases, the ventilation and evaporation properties of the synthetic garment may prove beneficial in the preservation of body temperature during exercise in the heat.