Sex differences in vascular and endothelial responses to acute mental stress

Coronary microvascular function in male physicians with burnout and job stress: an observational study

BACKGROUND

As a professional group, physicians are at increased risk of burnout and job stress, both of which are associated with an increased risk of coronary heart disease that is at least as high as that of other professionals. This study aimed to examine the association of burnout and job stress with coronary microvascular function, a predictor of major adverse cardiovascular events.

METHODS

Thirty male physicians with clinical burnout and 30 controls without burnout were included. Burnout was assessed with the Maslach Burnout Inventory and job stress with the effort-reward imbalance and overcommitment questionnaire. All participants underwent myocardial perfusion positron emission tomography to quantify endothelium-dependent (cold pressor test) and endothelium-independent (adenosine challenge) coronary microvascular function. Burnout and job stress were regressed on coronary flow reserve (primary outcome) and two additional measures of coronary microvascular function in the same model while adjusting for age and body mass index.

RESULTS

Burnout and job stress were significantly and independently associated with endothelium-dependent microvascular function. Burnout was positively associated with coronary flow reserve, myocardial blood flow response, and hyperemic myocardial blood flow (r partial = 0.28 to 0.35; p-value = 0.008 to 0.035). Effort-reward ratio (r partial =  - 0.32 to - 0.38; p-value = 0.004 to 0.015) and overcommitment (r partial =  - 0.30 to - 0.37; p-value = 0.005 to 0.022) showed inverse associations with these measures.

CONCLUSIONS

In male physicians, burnout and high job stress showed opposite associations with coronary microvascular endothelial function. Longitudinal studies are needed to show potential clinical implications and temporal relationships between work-related variables and coronary microvascular function. Future studies should include burnout and job stress for a more nuanced understanding of their potential role in cardiovascular health.

Gender medicine: effects of sex and gender on cardiovascular disease manifestation and outcomes

Despite a growing body of evidence, the distinct contributions of biological sex and the sociocultural dimension of gender to the manifestations and outcomes of ischaemic heart disease and heart failure remain unknown. The intertwining of sex-based differences in genetic and hormonal mechanisms with the complex dimension of gender and its different components and determinants that result in different disease phenotypes in women and men needs to be elucidated. The relative contribution of purely biological factors, such as genes and hormones, to cardiovascular phenotypes and outcomes is not yet fully understood. Increasing awareness of the effects of gender has led to efforts to measure gender in retrospective and prospective clinical studies and the development of gender scores. However, the synergistic or opposing effects of sex and gender on cardiovascular traits and on ischaemic heart disease and heart failure mechanisms have not yet been systematically described. Furthermore, specific considerations of sex-related and gender-related factors in gender dysphoria or in heart-brain interactions and their association with cardiovascular disease are still lacking. In this Review, we summarize contemporary evidence on the distinct effects of sex and gender as well as of their interactions on cardiovascular disease and how they favourably or unfavourably influence the pathogenesis, clinical manifestations and treatment responses in patients with ischaemic heart disease or heart failure.

The sex-dependent response to psychosocial stress and ischaemic heart disease

Stress is an important risk factor for modern chronic diseases, with distinct influences in males and females. The sex specificity of the mammalian stress response contributes to the sex-dependent development and impacts of coronary artery disease (CAD). Compared to men, women appear to have greater susceptibility to chronic forms of psychosocial stress, extending beyond an increased incidence of mood disorders to include a 2- to 4-fold higher risk of stress-dependent myocardial infarction in women, and up to 10-fold higher risk of Takotsubo syndrome-a stress-dependent coronary-myocardial disorder most prevalent in post-menopausal women. Sex differences arise at all levels of the stress response: from initial perception of stress to behavioural, cognitive, and affective responses and longer-term disease outcomes. These fundamental differences involve interactions between chromosomal and gonadal determinants, (mal)adaptive epigenetic modulation across the lifespan (particularly in early life), and the extrinsic influences of socio-cultural, economic, and environmental factors. Pre-clinical investigations of biological mechanisms support distinct early life programming and a heightened corticolimbic-noradrenaline-neuroinflammatory reactivity in females vs. males, among implicated determinants of the chronic stress response. Unravelling the intrinsic molecular, cellular and systems biological basis of these differences, and their interactions with external lifestyle/socio-cultural determinants, can guide preventative and therapeutic strategies to better target coronary heart disease in a tailored sex-specific manner.

The Impact of Mental Stress on Cardiovascular Health—Part II

Endothelial dysfunction is one of the earliest manifestations of atherosclerosis, contributing to its development and progression. Mental stress induces endothelial dysfunction through increased activity of the sympathetic nervous system, release of corticotropin-releasing hormone from the hypothalamus, inhibition of nitric oxide (NO) synthesis by cortisol, and increased levels of pro-inflammatory cytokines. Mental-stress-induced increased output of the sympathetic nervous system and concomitant withdrawal of the parasympathetic inflammatory reflex results in systemic inflammation and activation of a neural–hematopoietic–arterial axis. This includes the brainstem and subcortical regions network, bone marrow activation, release of leukocytes into the circulation and their migration to the arterial wall and atherosclerotic plaques. Low-grade, sterile inflammation is involved in all steps of atherogenesis, from coronary plaque formation to destabilisation and rupture. Increased sympathetic tone may cause arterial smooth-muscle-cell proliferation, resulting in vascular hypertrophy, thus contributing to the development of hypertension. Emotional events also cause instability of cardiac repolarisation due to brain lateralised imbalance of cardiac autonomic nervous stimulation, which may lead to asymmetric repolarisation and arrhythmia. Acute emotional stress can also provoke severe catecholamine release, leading to direct myocyte injury due to calcium overload, known as myocytolysis, coronary microvascular vasoconstriction, and an increase in left ventricular afterload. These changes can trigger a heart failure syndrome mimicking acute myocardial infarction, characterised by transient left ventricular dysfunction and apical ballooning, known as stress (Takotsubo) cardiomyopathy. Women are more prone than men to develop mental-stress-induced myocardial ischemia (MSIMI), probably reflecting gender differences in brain activation patterns during mental stress. Although guidelines on CV prevention recognise psychosocial factors as risk modifiers to improve risk prediction and decision making, the evidence that their assessment and treatment will prevent CAD needs further evaluation.

Mental Stress and Its Effects on Vascular Health

Coronary artery disease continues to be a major cause of morbidity and mortality despite significant advances in risk stratification and management. This has prompted the search for alternative nonconventional risk factors that may provide novel therapeutic targets. Psychosocial stress, or mental stress, has emerged as an important risk factor implicated in a higher incidence of cardiovascular events, and although our understanding of this far ranging and interesting phenomenon has developed greatly over recent times, there is still much to be learned regarding how to measure mental stress and how it may impact physical health. With the current coronavirus disease 2019 global pandemic and its incumbent lockdowns and social distancing, understanding the potentially harmful biological effects of stress related to life-changing events and social isolation has become even more important. In the current review our multidisciplinary team discusses stress from a psychosocial perspective and aims to define psychological stress as rigorously as possible; discuss the pathophysiologic mechanisms by which stress may mediate cardiovascular disease, with a particular focus to its effects on vascular health; outline existing methods and approaches to quantify stress by means of a vascular biomarker; outline the mechanisms whereby psychosocial stressors may have their pathologic effects ultimately transduced to the vasculature through the neuroendocrine immunologic axis; highlight areas for improvement to refine existing approaches in clinical research when studying the consequences of psychological stress on cardiovascular health; and discuss evidence-based therapies directed at reducing the deleterious effects of mental stress including those that target endothelial dysfunction. To this end we searched PubMed and Google Scholar to identify studies evaluating the relationship between mental or psychosocial stress and cardiovascular disease with a particular focus on vascular health. Search terms included "myocardial ischemia," "coronary artery disease," "mental stress," "psychological stress," "mental∗ stress∗," "psychologic∗ stress∗," and "cardiovascular disease∗." The search was limited to studies published in English in peer-reviewed journals between 1990 and the present day. To identify potential studies not captured by our database search strategy, we also searched studies listed in the bibliography of relevant publications and reviews.

Heart-brain interactions in cardiac and brain diseases: why sex matters

Cardiovascular disease and brain disorders, such as depression and cognitive dysfunction, are highly prevalent conditions and are among the leading causes limiting patient's quality of life. A growing body of evidence has shown an intimate crosstalk between the heart and the brain, resulting from a complex network of several physiological and neurohumoral circuits. From a pathophysiological perspective, both organs share common risk factors, such as hypertension, diabetes, smoking or dyslipidaemia, and are similarly affected by systemic inflammation, atherosclerosis, and dysfunction of the neuroendocrine system. In addition, there is an increasing awareness that physiological interactions between the two organs play important roles in potentiating disease and that sex- and gender-related differences modify those interactions between the heart and the brain over the entire lifespan. The present review summarizes contemporary evidence of the effect of sex on heart-brain interactions and how these influence pathogenesis, clinical manifestation, and treatment responses of specific heart and brain diseases.

Mental Stress-Induced Myocardial Ischemia

PURPOSE OF REVIEW

To summarize recent evidence on mental stress-induced myocardial ischemia (MSIMI), its mechanisms, and clinical significance.

RECENT FINDINGS

MSIMI can occur in patients with normal cardiac stress testing, is only weakly related to severity of coronary artery disease (CAD), and it is often silent. Among patients with CAD, MSIMI is associated with a twofold increased risk of major adverse cardiovascular events compared to those who do not have MSIMI. Certain groups such as young women with myocardial infarction and those with psychological comorbidities are more susceptible to MSIMI. Abnormal microvascular vasoreactivity and inflammation are implicated mechanisms in MSIMI. Increased brain activity in regions that modulate autonomic reactivity to emotional stress and fear is associated with MSIMI. MSIMI has important prognostic implications in patients with CAD. Stress can no longer be ignored as a risk factor in cardiology care. Clinical trials testing effective strategies to target MSIMI are needed.

The Role of Mental Stress in Ischaemia with No Obstructive Coronary Artery Disease and Coronary Vasomotor Disorders

Ischaemic heart disease has been estimated to affect 126.5 million people globally. Approximately 70% of patients with angina and suspected myocardial ischaemia show no signs of obstructed coronary arteries after coronary angiography, but may still demonstrate ischaemia. Ischaemia with no obstructive coronary artery disease (INOCA) is increasingly acknowledged as a serious condition because of its association with poor quality of life and elevated risk for cardiovascular events. The negative effects of psychological stress on INOCA are gaining more attention. Psychological stress is associated with adverse cardiovascular outcomes such as mental stress-induced myocardial ischaemia. Psychological stress includes anxiety, depression, anger and personality disturbances. Coronary microvascular dysfunction and coronary arterial spasm are phenotypes of coronary vasomotor disorders that are triggered by psychological distress and depression, thereby increasing cardiovascular disease risk. Coronary vasomotor disorders are often co-existent in INOCA patients and might be considered as a contributing factor to mental stress-associated adverse cardiovascular outcomes. Additionally, psychological stress induces endothelial dysfunction more often in (young) women with INOCA than in men. Overall, many studies demonstrate an association between mental stress, coronary microvascular dysfunction and coronary vasospasm in patients with INOCA - especially women. Future research on stress-reducing therapies that target coronary vasomotor disorders in patients with INOCA is needed. This is particularly the case in young adolescents, in whom this type of ischaemic heart disease is increasing.

Cocoa Flavanols Improve Vascular Responses to Acute Mental Stress in Young Healthy Adults

Mental stress has been shown to induce cardiovascular events, likely due to its negative impact on vascular function. Flavanols, plant-derived polyphenolic compounds, improve endothelial function and blood pressure (BP) in humans, however their effects during stress are not known. This study examined the effects of acute intake of cocoa flavanols on stress-induced changes on vascular function. In a randomised, controlled, double-blind, cross-over intervention study, 30 healthy men ingested a cocoa flavanol beverage (high-flavanol: 150 mg vs. low-flavanol < 4 mg (-)-epicatechin) 1.5 h before an 8-min mental stress task). Forearm blood flow (FBF), BP, and cardiovascular activity were assessed pre- and post-intervention, both at rest and during stress. Endothelial function (brachial flow-mediated dilatation, FMD) and brachial BP were measured before the intervention and 30 and 90 min post-stress. FMD was impaired 30 min post-stress, yet high-flavanol cocoa attenuated this decline and remained significantly higher compared to low-flavanol cocoa at 90 min post-stress. High-flavanol cocoa increased FBF at rest and during stress. Stress-induced cardiovascular and BP responses were similar in both conditions. Flavanols are effective at counteracting mental stress-induced endothelial dysfunction and improving peripheral blood flow during stress. These findings suggest the use of flavanol-rich dietary strategies to protect vascular health during stress.

Predictive value of vascular response to cuff inflation-induced pain in the control arm for adverse cardiovascular events

Background

The high incidence rate of cardiovascular (CV) events had led to a comprehensive appraisal for identifying patients who are at risk for CV disease. However, CV traditional risk factors, such as Framingham risk score (FRS), failed exhaustively to predict CV events.

Methods

402 participants (mean age, 58 [12] years; 45% male) using fingertip peripheral artery tonometry at Mayo Clinic in Rochester, Minnesota, were recruited in the present study. Measurements included reactive hyperemia index (RHI) and pain-induced peripheral artery tonometry (PIPAT).

Results

After a median follow-up of 3.8 (2.7–7.7) years, 95 CV events occurred. Both first minute PIPAT and RHI were independently associated with events (hazard ratio [HR], 0.77 [95% CI, 0.61–0.98]; P = 0.038 and HR, 0.75 [95% CI, 0.59–0.96]; P = 0.019, respectively). The C statistic values of FRS, FRS + first minute PIPAT, FRS + RHI, and FRS + RHI + first minute PIPAT were 0.704, 0.722, 0.694, and 0.726, respectively. Furthermore, the addition of first minute PIPAT, RHI, and first minute PIPAT + RHI to FRS results in net reclassification improvement (NRI) in the intermediate-risk group (18.1%, P = 0.031; 18.1%, P = 0.035; 21%, P = 0.013).

Conclusion

First minute PIPAT is a risk marker for adverse CV. Addition of first minute PIPAT to FRS increased the discrimination in the receiver operating characteristic analysis. It also increased NRI compared with FRS alone.

Sex differences in the association between PTSD symptoms with cardiac autonomic function and subclinical atherosclerotic risk

BACKGROUND

Post-traumatic stress disorder (PTSD) is a public health concern that may elevate the risk for cardiovascular disease (CVD). There are established sex differences in both PTSD risk and CVD risk.

PURPOSE

To examine sex-specific associations between subclinical PTSD symptom severity and subclinical CVD risk in young men and women.

METHODS

A total of 61 young adults (women: n = 29, mean age: 26 ± 7 years) completed the post-traumatic stress disorder civilian checklist (PCL) and the Center for Epidemiologic Studies Depression Scale (CES-D). Aortic stiffness was measured as carotid-femoral pulse wave velocity (cfPWV). Peripheral vasomotor function was measured as flow-mediated slowing (FMS) of carotid-radial PWV following 5-min forearm occlusion. Heart rate variability was used to assess sympathovagal balance as LF/HF ratio.

RESULTS

PCL score was positively correlated with CES-D score (r = 0.79, p < .001), cfPWV (r = 0.33, p = .03) and LF/HF ratio (r = 0.42, p = .009) in men. PCL score was positively correlated to CES-D score (r = 0.80, p < .001) in women, but was inversely correlated to cfPWV (r = -0.38, p = .02) and LF/HF ratio (r = -0.34, p = .04). PCL score was also inversely associated with FMS in women (r = -0.49, p = .01).

CONCLUSION

There are sex differences in the association of PTSD symptoms and subclinical atherosclerosis. In men, increased PTSD symptoms may increase CVD risk by increasing sympathovagal balance and aortic stiffness. In women, increased PTSD symptoms may increase CVD risk via reducing vasomotor function.

Peripheral endothelial dysfunction is a novel risk factor for systolic dysfunction and heart failure progression

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Peripheral endothelial dysfunction (PED) predicts adverse outcomes in patients with stage B HF.

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PED was independently associated with stage B HF, even after adjusting for co-variables.

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PED was strongly associated with progression from stage B to overt stage C HF.

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Detecting PED may stratify the risk of HF progression.

Background

ACC/AHA guidelines recognize the progressive nature of heart failure (HF). Patients with risk factors (Stage A) are at risk for developing asymptomatic cardiac dysfunction (Stage B), which may then lead to symptomatic HF (Stage C). As such, therapies targeting abnormalities in stages A and B may protect against development of symptomatic HF. peripheral endothelial dysfunction (PED) is an independent predictor of adverse outcomes in patients with stage C HF. The aim of the current study was to evaluate whether PED might be associated with Stage B HF, where therapeutic interventions to prevent progression might be more efficacious.

Methods

We performed a retrospective cross-sectional analysis of patients who were referred for routine cardiovascular evaluation that included an assessment of peripheral endothelial function with reactive hyperemia-peripheral arterial tonometry. Individuals in this study underwent routine clinically indicated echocardiography within 2 months of testing for PED. Patients with clinical HF were excluded.

Results

The study included 355 patients (mean age 51.5 ± 14.6 years, 231 (65.1%) female). There was a significant association between PED and Stage B HF (Odds Ratio (OR) 6.38; P < 0.0001) that persisted after stratifying by sex. In multivariate analyses PED was significantly associated with Stage B HF (OR 5.33; P = 0.0038), and was also associated with progression to overt stage C HF (OR 4.63; P = 0.033).

Conclusion

Peripheral endothelial dysfunction is risk factor for Stage B HF, even in low risk individuals. Further study is warranted to better understand the mechanistic basis of PED in HF to reduce the risk of symptomatic progression.

How Does Mental Health Impact Women's Heart Health?

From adolescence until old age, women are more vulnerable to common mental disorders (CMDs; depression and anxiety) than men at all stages of the life course. By middle age, women who have clinical depression are at twice the risk of having an incident cardiovascular disease (CVD) than those without. This has important implications for the way we prevent, identify and treat both CMDs and coronary heart disease in women. In this paper, we discuss the various genetic, biological, ethnic/racial, and psychological pathways by which women's vulnerability to CMDs elevate their CVD risk and recovery from a cardiac event. We review the evidence from trials that have, to date, failed to show that treating depression can reduce or delay the onset or recurrence of CVD events, especially for female patients. We discuss the value of lifestyle-based therapies for treating depression, to which women may be more responsive, and finish by discussing how population-based approaches including risk factor assessment could be tailored to consider these factors.

Vascular reactivity to mental stress is associated with poor cardiovascular disease outcomes in females following acute coronary syndrome

BACKGROUND

We aimed to test the hypothesis that peripheral endothelial dysfunction induced by mental stress may predict cardiovascular events after acute coronary syndrome beyond traditional cardiovascular disease risk factors.

METHODS

This was a prospective study in which 417 patients who had acute coronary syndrome were enrolled in two sites at the US and Qatar. Cardiovascular disease risk factors such as past medical history, blood pressure, heart rate, peripheral endothelial dysfunction, and response to three different mental stress examinations (Stroop Color Word, Arithmetic, and Spiral Omnibus) as assessed by ratio of reactive hyperemia tonometry (EndoPAT) with stress over EndoPAT at rest were obtained at baseline. Major adverse cardiac events were then recorded at 1 year after the index event.

RESULTS

There were no differences in baseline peripheral endothelial dysfunction or vascular response to mental stress between the US vs. Qatar patients. Women were more likely to experience major adverse cardiac events in the year following acute coronary syndrome (relative risk 2.42, 95% confidence interval 1.53-3.84, P = 0.044), and had a significantly lower mental stress ratio compared to women who did not (1.0 ± 0.17 vs. 1.20 ± 0.17, P = 0.04). In multivariate analyses stratified by sex, baseline peripheral endothelial dysfunction (EndoPAT < 1.7) (χ = 8.0, P = 0.005) and mental stress ratio (χ = 7.7, P = 0.006), were independently predictive of major adverse cardiac events in women, but not men.

CONCLUSION

The current study demonstrates that in women both baseline endothelial function and vascular function in response to mental stress ratio are predictive of worse cardiovascular disease outcomes 1 year after acute coronary syndrome. The study may suggest an important mechanism for adverse clinical outcomes in women following acute coronary syndrome.

Elevated serum uric acid is associated with peripheral endothelial dysfunction in women

BACKGROUND AND AIMS

Both elevated serum uric acid (SUA) and peripheral endothelial dysfunction (PED) are associated independently with cardiovascular disease (CVD). However, the association between SUA and PED is yet to be established. We hypothesized that high normal range of SUA is associated with PED.

METHODS

We performed a retrospective cross-sectional analysis of patients who were referred to Mayo Clinic between 2006 and 2014 for routine cardiovascular evaluation and who underwent evaluation of Reactive Hyperemia Peripheral Arterial Tonometry (index <2 consistent with PED). A high UA was defined as ≥5 mg/dL, in keeping with previous studies evaluating the link between SUA and CVD outcomes.

RESULTS

One hundred forty patients were included (mean age 50.7 ± 12.9 years, 86 (61.4%) female). Twenty four patients (17.1%) had pre-existing CVD (8 (9.3%) in females). Thirty patients (21.6%) had a Framingham score > 10% (8 (9.4%) in females). Fifty eight (41.4%) had PED and 77 (55.0%) had an elevated SUA. SUA levels were higher in patients with PED compared to those without (5.5 ± 1.4 vs 4.8 ± 1.2 mg/dL; p = 0.004). In an univariate analysis, elevated SUA levels were associated with PED (Odds Ratio (OR): 2.7; 95% confidence interval [CI] 1.33-5.48; p = 0.005). In a multivariate analysis adjusting for age, sex, presence of obstructive CVD and Framingham score>10, elevated SUA levels were associated with PED (OR 2.45; 95% CI 1.08-5.52; p = 0.031). After stratifying by sex, this association persisted in females only.

CONCLUSIONS

High normal SUA levels are associated with PED in women who are otherwise at low risk for CVD. Thus, SUA is a promising circulating biomarker that could be used to assist in risk stratification in female patients with chest pain and/or those undergoing evaluation of CVD risk.

Neuroinflammation caused by mental stress: the effect of chronic restraint stress and acute repeated social defeat stress in mice

Objectives: Cerebrovascular disease (CVD) is the leading cause of permanent disability worldwide. Inflammation has been reported to play an important role in the progression of CVD. Neuropsychiatric disorders such as depression are associated with increased incidence of CVD epidemiologically, although the mechanisms underlying this association are not clear. In this study, we assessed the effect of the acute repeated social defeat stress (RSDS) and chronic restraint stress (CRS) on neuroinflammation in mice. Methods: A total of 40 6-week-old male C57BL/6J mice were divided into RSDS, CRS, and corresponding control groups. In the RSDS group, male C57BL/6J mice were repeatedly subjected to bouts of social defeat by a larger CD-1 mouse for 10 min daily for 10 consecutive days. In the CRS group, the mice were exposed to restraint stress for 6 h per day for 28 consecutive days. Depressive behavior was evaluated by conducting sucrose preference test over 24 h. Peripheral blood serum and brain tissues were collected for measurement of corticosterone (CORT), epinephrine (EPI), and inflammatory factors (TNF-α and IL-6) using ELISA or real-time PCR 24 h after the sucrose preference test. Results: Both RSDS and CRS decreased the sucrose preference ratio. The acute stress increased serum CORT and EPI, while the chronic stress did not significantly influence them. Both stress models induced an inflammatory response in peripheral serum and the brain. Conclusions: RSDS and CRS are two effective models of depressive behavior, and both models cause neuroinflammation, which may be responsible for the increased risk of CVD seen in patients with depression.

Pain-induced peripheral artery tonometry scores in the control arm are impaired in patients with apical ballooning syndrome

Mental and physical stress is thought to play an important causative factor in apical ballooning syndrome (ABS) likely secondary to the vasomotor dysfunction. However, there are currently few data related to the impact of physical stress in this unique cardiomyopathy.A total 18 patients, including 8 females with history of ABS and 10 post-menopausal controls, underwent physical and mental tests. Assessments included the pain-induced peripheral artery tonometry scores (PIPATs) and mental stress peripheral artery tonometry scores (PATs).Compared with control group, PIPATs were significantly attenuated in patients with ABS in both baseline and post-mental stress (0.94 ± 0.08 vs1.30 ± 0.54, P <.05 and 0.87 ± 0.19 vs1.24 ± 0.21 P = .01, respectively); mental stress PATs were significantly lower in patients with ABS, both in Stroop test (0.79 ± 0.30 vs 1.24 ± 0.43, P = .01) and arithmetic test (0.91 ± 0.27 vs 1.36 ± 0.57, P = .01). PIPATs correlated significantly with mental stress PATs, both in arithmetic and Stroop test (P <.05).The PIPATs were attenuated in female with history of ABS and the vascular response to pain may provide a different pathogenesis mechanism on detecting patients with ABS.

Non-ST elevation acute coronary syndrome in women and the elderly: recent updates and stones still left unturned

Despite the growing awareness of adverse events with acute coronary syndrome and vigilance to refine pharmacological and interventional therapies, the understanding of how these events present in and affect women and the elderly remains limited. Pathophysiological differences in these subgroups and under-representation in large trials create a medical gap in sex- and age-related outcomes and in our knowledge of how best to detect, diagnose, and treat acute coronary syndrome. This review provides a general overview of recent advances in non-ST elevation myocardial infarction management in women and the elderly and elucidates areas where further exploration is needed.

Role of Stress and Psychosocial Determinants on Women's Cardiovascular Risk and Disease Development

The notion that cardiovascular disease (CVD) primarily occurs in men is slowly disappearing. More women than men die of CVD every year, and when women survive, the burden and consequences are worse than in men. Markers of stress and other psychosocial factors have been associated with poor outcomes. Multiple studies have demonstrated sex-based differences in the vascular and endothelial responses to mental stress. Psychosocial stressors were also found to be independent risk factors for the development and progression of CVD. This review arises from accumulating evidence suggesting that psychological well-being may improve cardiac-related outcomes, independent of cardiac risk factors. Despite the fact that positive physician-patient engagement is likely to play a critical role in promoting positive psychological traits and healthy behaviors, current physician awareness and advocacy are rather suboptimal, despite active awareness campaigns such as the American Heart Association's Go Red for Women^®. There is a need to further study the role and management of stress as a CVD risk factor, especially in women, who are disproportionately affected.

Mental stress peripheral vascular reactivity is elevated in women with coronary vascular dysfunction: Results from the NHLBI-sponsored Cardiac Autonomic Nervous System (CANS) study

BACKGROUND

Women with chest pain, ischemia, and no obstructive coronary artery disease often have coronary vascular dysfunction (CVaD). Peripheral vascular reactivity to mental stress may contribute mechanistic understanding of stress-induced ischemia in women with CVaD.

METHODS

62 women (41 CVaD and 21 controls) underwent mental stress testing (MST) with anger recall, mental arithmetic, and forehead cold pressor (COP) challenge. Emotional arousal was measured (Likert scale). Reactive hyperemia index (RHI) was calculated before and after MST by peripheral arterial tonometry (PAT). Stress PAT ratio (SPR) of pulse amplitude during stress to rest was obtained to measure vasoconstriction. Wilcoxson rank sum test was used for analysis.

RESULTS

Mean age of CVaD and control groups was 58±9 and 55±10years (p=0.73). Baseline RHI correlated with coronary endothelial function (r=0.36, p=0.03) and inversely with RHI change post-MST (r=-0.51, p<0.001). During MST, 10% of controls reported chest pain vs. 41% of CVaD subjects (p=0.01). RHI did not change significantly after MST in either group. CVaD subjects had lower SPR vs. controls during mental arithmetic (0.54 [0.15, 1.46] vs. 0.67 [0.36, 1.8], p=0.039), not evident in the other tasks. Vasoconstriction inversely correlated with anxiety (r=-3.4, p=0.03), frustration (r=-0.37, p=0.02), and feeling challenged (r=-0.37, p=0.02) in CVaD but not controls.

CONCLUSIONS

Mental stress peripheral vascular reactivity is elevated in women with CVaD compared to controls. Elevated vascular reactivity may be one contributor to stress-induced chest pain in CVaD. Interventions that modulate vasoconstrictive responses may be of benefit and should be tested in clinical trials in women with CVaD.

Sex Differences in Hemodynamic and Microvascular Mechanisms of Myocardial Ischemia Induced by Mental Stress

OBJECTIVE

To investigate sex-specific vascular mechanisms for mental stress-induced myocardial ischemia (MSIMI).

APPROACH AND RESULTS

Baseline data from a prospective cohort study of 678 patients with coronary artery disease underwent myocardial perfusion imaging before and during a public speaking stressor. The rate-pressure product response was calculated as the difference between the maximum value during the speech minus the minimum value during rest. Peripheral vasoconstriction by peripheral arterial tonometry was calculated as the ratio of pulse wave amplitude during the speech over the resting baseline; ratios <1 indicate a vasoconstrictive response. MSIMI was defined as percent of left ventricle that was ischemic and as a dichotomous variable. Men (but not women) with MSIMI had a higher rate-pressure product response than those without MSIMI (6500 versus 4800 mm Hg bpm), whereas women (but not men) with MSIMI had a significantly lower peripheral arterial tonometry ratio than those without MSIMI (0.5 versus 0.8). In adjusted linear regression, each 1000-U increase in rate-pressure product response was associated with 0.32% (95% confidence interval, 0.22-0.42) increase in inducible ischemia among men, whereas each 0.10-U decrease in peripheral arterial tonometry ratio was associated with 0.23% (95% confidence interval, 0.11-0.35) increase in inducible myocardial ischemia among women. Results were independent of conventional stress-induced myocardial ischemia.

CONCLUSIONS

Women and men have distinct cardiovascular reactivity mechanisms for MSIMI. For women, stress-induced peripheral vasoconstriction with mental stress, and not increased hemodynamic workload, is associated with MSIMI, whereas for men, it is the opposite. Future studies should examine these pathways on long-term outcomes.

The impact of repetitive long-duration water immersion on vascular function

While physiological responses to water immersion (WI) are well-studied, the vascular responses after WI are less understood. Fifteen male subjects performed six-hour resting thermoneutral water immersions (WI) at 1.35 atmospheres absolute for four consecutive days, with follow-up on the fifth day. Measurements included peripheral endothelial function and augmentation index (PAT, peripheral arterial tonometry), beat-to-beat blood pressure (BP, photoplethysmography), heart rate (HR), and plasma volume (PV) calculated from changes in hemoglobin and hematocrit. The reactive hyperemia index (RHI), a marker of peripheral endothelial function, increased with repeated immersions (p = 0.008). By WI2 and WI3, RHI increased 12% and 16%, respectively, compared to WI1 values, but no significant differences were detected between WI4 and WI1 for either measure. Absolute augmentation index (AI) increased by an average of 33% (p<0.001) and AI normalized for HR (AI@75) by 11% (p = 0.12) following each WI. PV decreased significantly by 13.2% following WI and remained 6.8% lower at follow-up compared to pre-WI. Systolic blood pressure significantly decreased by an average of 2.5% following each WI (p = 0.012). Compared to pre-WI HR, average post-WI HR decreased 4.3% lower (p<0.001), but increased overall by 8.2% over the course of repeated WI (p<0.001). Total peripheral resistance increased by an average of 13.1% following WI (p = 0.003). Thus, peripheral endothelial function increases after two days of WI, and PAT-derived measures of arterial stiffness increase transiently post-WI. Additionally, BP and PAT-derived endothelial function diverge from their usual associations with arterial stiffness (i.e. augmentation index) in the context of WI.

The Impact of Multipollutant Clusters on the Association Between Fine Particulate Air Pollution and Microvascular Function

BACKGROUND

Prior studies including the Framingham Heart Study have suggested associations between single components of air pollution and vascular function; however, underlying mixtures of air pollution may have distinct associations with vascular function.

METHODS

We used a k-means approach to construct five distinct pollution mixtures from elemental analyses of particle filters, air pollution monitoring data, and meteorology. Exposure was modeled as an interaction between fine particle mass (PM2.5), and concurrent pollution cluster. Outcome variables were two measures of microvascular function in the fingertip in the Framingham Offspring and Third Generation cohorts from 2003 to 2008.

RESULTS

In 1,720 participants, associations between PM2.5 and baseline pulse amplitude tonometry differed by air pollution cluster (interaction P value 0.009). Higher PM2.5 on days with low mass concentrations but high proportion of ultrafine particles from traffic was associated with 18% (95% confidence interval: 4.6%, 33%) higher baseline pulse amplitude per 5 μg/m and days with high contributions of oil and wood combustion with 16% (95% confidence interval: 0.2%, 34%) higher baseline pulse amplitude. We observed no variation in associations of PM2.5 with hyperemic response to ischemia observed across air pollution clusters.

CONCLUSIONS

PM2.5 exposure from air pollution mixtures with large contributions of local ultrafine particles from traffic, heating oil, and wood combustion was associated with higher baseline pulse amplitude but not hyperemic response. Our findings suggest little association between acute exposure to air pollution clusters reflective of select sources and hyperemic response to ischemia, but possible associations with excessive small artery pulsatility with potentially deleterious microvascular consequences.

Sex Differences in Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Heart Disease

BACKGROUND

Emerging data suggest that young women with coronary heart disease (CHD) are disproportionally vulnerable to the adverse cardiovascular effects of psychological stress. We hypothesized that younger, but not older, women with stable CHD are more likely than their male peers to develop mental stress-induced myocardial ischemia (MSIMI).

METHODS AND RESULTS

We studied 686 patients (191 women) with stable coronary heart disease (CHD). Patients underwent (99m)Tc-sestamibi myocardial perfusion imaging at rest and with both mental (speech task) and conventional (exercise/pharmacological) stress testing. We compared quantitative (by automated software) and visual parameters of inducible ischemia between women and men and assessed age as an effect modifier. Women had a more-adverse psychosocial profile than men whereas there were few differences in medical history and CHD risk factors. Both quantitative and visual indicators of ischemia with mental stress were disproportionally larger in younger women. For each 10 years of decreasing age, the total reversibility severity score with mental stress was 9.6 incremental points higher (interaction, P<0.001) and the incidence of MSIMI was 82.6% higher (interaction, P=0.004) in women than in men. Incidence of MSIMI in women ≤50 years was almost 4-fold higher than in men of similar age and older patients. These results persisted when adjusting for sociodemographic and medical risk factors, psychosocial factors, and medications. There were no significant sex differences in inducible ischemia with conventional stress.

CONCLUSIONS

Young women with stable CHD are susceptible to MSIMI, which could play a role in the prognosis of this group.

Behavioral, emotional and neurobiological determinants of coronary heart disease risk in women

Women have more of the stress-related behavioral profile that has been linked to cardiovascular disease than men. For example, women double the rates of stress-related mental disorders such as depression and posttraumatic stress disorder (PTSD) than men, and have higher rates of exposure to adversity early in life. This profile may increase women's long-term risk of cardiometabolic conditions linked to stress, especially coronary heart disease (CHD). In addition to having a higher prevalence of psychosocial stressors, women may be more vulnerable to the adverse effects of these stressors on CHD, perhaps through altered neurobiological physiology. Emerging data suggest that young women are disproportionally susceptible to the adverse effects of stress on the risk of cardiovascular disease, both in terms of initiating the disease as well as worsening the prognosis in women who have already exhibited symptoms of the disease. Women's potential vulnerability to psychosocial stress could also help explain their higher propensity toward abnormal coronary vasomotion and microvascular disease compared with men.

The impact of sex and gender on adaptation to space: executive summary

This review article is a compendium of six individual manuscripts, a Commentary, and an Executive Summary. This body of work is entitled "The Impact of Sex and Gender on Adaptation to Space" and was developed in response to a recommendation from the 2011 National Academy of Sciences Decadal Survey, "Recapturing a Future for Space Exploration: Life and Physical Sciences for a New Era," which emphasized the need to fully understand sex and gender differences in space. To ensure the health and safety of male and female astronauts during long-duration space missions, it is imperative to examine and understand the influences that sex and gender have on physiological and psychological changes that occur during spaceflight. In this collection of manuscripts, six workgroups investigated and summarized the current body of published and unpublished human and animal research performed to date related to sex- and gender-based differences in the areas of cardiovascular, immunological, sensorimotor, musculoskeletal, reproductive, and behavioral adaptations to human spaceflight. Each workgroup consisted of scientists and clinicians from academia, the National Aeronautics and Space Administration (NASA), and other federal agencies and was co-chaired by one representative from NASA and one from the external scientific community. The workgroups met via telephone and e-mail over 6 months to review literature and data from space- and ground-based studies to identify sex and gender factors affecting crew health. In particular, the Life Sciences Data Archive and the Lifetime Surveillance of Astronaut Health were extensively mined. The groups identified certain sex-related differences that impact the risks and the optimal medical care required by space-faring women and men. It represents innovative research in sex and gender-based biology that impacts those individuals that are at the forefront of space exploration.

Sex differences in platelet reactivity and cardiovascular and psychological response to mental stress in patients with stable ischemic heart disease: insights from the REMIT study

BACKGROUND

Although emotional stress is associated with ischemic heart disease (IHD) and related clinical events, sex-specific differences in the psychobiological response to mental stress have not been clearly identified.

OBJECTIVES

We aimed to study the differential psychological and cardiovascular responses to mental stress between male and female patients with stable IHD.

METHODS

Patients with stable IHD enrolled in the REMIT (Responses of Mental Stress-Induced Myocardial Ischemia to Escitalopram) study underwent psychometric assessments, transthoracic echocardiography, and platelet aggregation studies at baseline and after 3 mental stress tasks. Mental stress-induced myocardial ischemia (MSIMI) was defined as the development or worsening of regional wall motion abnormality, reduction of left ventricular ejection fraction (LVEF) ≥8% by transthoracic echocardiography, and/or ischemic ST-segment change on electrocardiogram during 1 or more of the 3 mental stress tasks.

RESULTS

In the 310 participants with known IHD (18% women, 82% men), most baseline characteristics were similar between women and men (including heart rate, blood pressure, and LVEF), although women were more likely to be nonwhite, living alone (p < 0.001), and unmarried (p < 0.001); they also had higher baseline depression and anxiety (p < 0.05). At rest, women had heightened platelet aggregation responses to serotonin (p = 0.007) and epinephrine (p = 0.004) compared with men. Following mental stress, women had more MSIMI (57% vs. 41%; p < 0.04), expressed more negative (p = 0.02) and less positive emotion (p < 0.001), and demonstrated higher collagen-stimulated platelet aggregation responses (p = 0.04) than men. Men were more likely than women to show changes in traditional physiological measures, such as blood pressure (p < 0.05) and double product.

CONCLUSIONS

In this exploratory analysis, we identified clear, measurable, and differential responses to mental stress in women and men. Further studies should test the association of sex differences in cardiovascular and platelet reactivity in response to mental stress and long-term outcomes. (Responses of Myocardial Ischemia to Escitalopram Treatment [REMIT]; NCT00574847).

The importance of functional tests in personalized medicine

Cardiovascular disease is the most prevalent disease mainly in the Western society and becoming the leading cause of death worldwide. Standard methods by which healthcare providers screen for cardiovascular disease have only minimally reduced the burden of disease while exponentially increasing costs. As such, more specific and individualized methods for functionally assessing cardiovascular threats are needed to identify properly those at greatest risk, and appropriately treat these patients so as to avoid a fate such as heart attack, stroke, or death. Currently, endothelial function testing-in both the coronary and peripheral circulation-is well established as being associated with the disease process and future cardiovascular events. Improving such testing can lead to a reduction in the risk of future events. Combining this functional assessment of vascular fitness with other, more personalized, testing methods should serve to identify those at the greatest risk of cardiovascular disease earlier and subsequently reduce the affliction of such diseases worldwide.

Strategies and methods to study sex differences in cardiovascular structure and function: a guide for basic scientists

Background

Cardiovascular disease remains the primary cause of death worldwide. In the US, deaths due to cardiovascular disease for women exceed those of men. While cultural and psychosocial factors such as education, economic status, marital status and access to healthcare contribute to sex differences in adverse outcomes, physiological and molecular bases of differences between women and men that contribute to development of cardiovascular disease and response to therapy remain underexplored.

Methods

This article describes concepts, methods and procedures to assist in the design of animal and tissue/cell based studies of sex differences in cardiovascular structure, function and models of disease.

Results

To address knowledge gaps, study designs must incorporate appropriate experimental material including species/strain characteristics, sex and hormonal status. Determining whether a sex difference exists in a trait must take into account the reproductive status and history of the animal including those used for tissue (cell) harvest, such as the presence of gonadal steroids at the time of testing, during development or number of pregnancies. When selecting the type of experimental animal, additional consideration should be given to diet requirements (soy or plant based influencing consumption of phytoestrogen), lifespan, frequency of estrous cycle in females, and ability to investigate developmental or environmental components of disease modulation. Stress imposed by disruption of sleep/wake cycles, patterns of social interaction (or degree of social isolation), or handling may influence adrenal hormones that interact with pathways activated by the sex steroid hormones. Care must be given to selection of hormonal treatment and route of administration.

Conclusions

Accounting for sex in the design and interpretation of studies including pharmacological effects of drugs is essential to increase the foundation of basic knowledge upon which to build translational approaches to prevent, diagnose and treat cardiovascular diseases in humans.

Assessment of coronary endothelial function using PET

Endothelial dysfunction is the earliest abnormality in the development of coronary atherosclerosis. Several coronary risk factors adversely affect endothelial function. Therefore, a finding of endothelial dysfunction may guide interventions for preventing the development of future cardiovascular events. The non-invasive aspects and coronary specificity of measurements of myocardial blood flow (MBF) using positron emission tomography (PET) with sympathetic stress make it widely applicable for the evaluation of endothelial function. PET MBF measurements with sympathetic stress have been applied to a variety of subjects with coronary risk factors and have been shown to have value for risk assessment in these subjects. Endothelial measurement using PET remains an ideal research tool for the study of the pathophysiology of several cardiac diseases. PET is also well suited for the acute and longitudinal evaluation of treatment. Thus, the continued development of this approach for the evaluation of new treatment effects should be expected.

Comparing EndoPAT and BIOPAC measurement of vascular responses to mental stress

There are currently no comparison measurements of stress-induced changes in vascular function during acute mental stress tests to measurements made by BIOPAC MP150 systems technology, a standard polygraph device used to detect deception during polygraph examinations in military or law enforcement applications. Vascular responses to reactive hyperaemia and acute mental stress in 25 healthy subjects were measured by both peripheral arterial tonometry (EndoPAT) and a blood pressure cuff attached to a pressure transducer (BIOPAC) and compared. Reactive hyperaemia was performed at baseline and following three acute mental stress tests. There was no difference in vascular reactivity at baseline and following acute mental stress, as measured by EndoPAT or BIOPAC systems (p > 0·05). Mental stress ratios measured by EndoPAT were significantly different than those measured by BIOPAC (p < 0·01). These data suggest that EndoPAT measurements of vascular responses to acute mental stress may be more specific and sensitive than measurements using the BIOPAC system.

Endothelial function and vascular response to mental stress are impaired in patients with apical ballooning syndrome

OBJECTIVES

The aim of the current study was to test the hypothesis that vascular and endothelial functional responses to acute mental stress are abnormal in patients with apical ballooning syndrome (ABS).

BACKGROUND

Apical ballooning syndrome is a transient cardiomyopathy that occurs predominantly in post-menopausal women and may be triggered by acute mental stress. The mechanism for ABS is unknown.

METHODS

Reactive hyperemia as a parameter of endothelial function and vascular responses to acute mental stress were measured using peripheral arterial tonometry (PAT) at baseline and following 3 acute mental stress tests in female patients with ABS (n = 12, at least 6 months after being hospitalized or diagnosed with ABS), post-menopausal female controls (n = 12), and female patients with myocardial infarction (MI) (n = 4). Plasma catecholamine levels were measured at baseline and following the 3 mental stress tests.

RESULTS

Reactive hyperemia PAT scores following mental stress were significantly lower in patients with ABS compared with post-menopausal controls (p < 0.05). The PAT scores during mental stress were significantly lower in patients with ABS compared with patients with MI and post-menopausal controls (p < 0.05). There were no differences in PAT scores during acute mental stress in patients with MI versus post-menopausal controls. Furthermore, catecholamine levels were significantly increased in patients with ABS, compared with post-menopausal controls, following acute mental stress testing (p < 0.05).

CONCLUSIONS

There is increased vascular reactivity and decreased endothelial function in response to acute mental stress in patients with a prior episode of ABS. The findings implicate vasomotor dysfunction as a potential mechanism involved in the pathogenesis of this unique cardiomyopathy.

Assessment of endothelial function using digital pulse amplitude tonometry

The importance of endothelial dysfunction in the development and clinical expression of cardiovascular disease is well recognized. Impaired endothelial function has been associated with an increased risk of cardiovascular events. Endothelial function may be evaluated in humans by assessing vasodilation in response to stimuli known to induce the release of nitric oxide. A novel pulse amplitude tonometry device noninvasively measures vasodilator function in the microcirculation of the finger. This article reviews the recent studies that support the utility of digital pulse amplitude tonometry as a relevant test of peripheral endothelial function.