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

Research progress regarding the diagnosis and treatment of mental stress-induced myocardial ischemia

Myocardial ischemia resulting from psychological stress [mental stress-induced myocardial ischemia (MSIMI)] refers to the condition wherein psychosocial and psychological stimulations cause myocardial ischemia in patients with coronary heart disease, which is different from drug-induced myocardial ischemia. Therefore, this condition often escapes diagnosis, portends clinical risk, and affects the quality of life of MSIMI survivors. MSIMI is closely related to the poor prognosis of cardiovascular diseases, especially in young women, according to recent randomized, controlled trials (RCTs) on MSIMI. These RCTs involved different sample sizes, interventional measures, and detection techniques. Moreover, differences exist regarding the prevalence rate, distribution characteristics, possible pathogenesis, and clinical significance. Nevertheless, currently, the diagnostic criteria, pathogenesis, and treatment of MSIMI are still in the clinical exploration stage. Hence, considering recent RCTs, this paper summarizes the research status of MSIMI from the aspects of pathogenesis, diagnosis, and treatment strategies to provide a theoretical basis for the follow-up diagnostic methods and treatment guidelines for MSIMI.

What Do We Know About Young Adult Cardiac Patients' Experience? A Systematic Review

Background: Studies interested in patients coping with a cardiac illness usually focus on children, teenagers, and adults above the age of 55. Apart from the field of congenital heart diseases, there is a general lack of literature regarding young adult cardiac patients (18-55 years old) who seem to cope with psychosocial issues. Therefore, the objective of this paper was to gather all the research carried out concerning the psychological experiences of young adult cardiac patients. Methods and Results: A comprehensive, systematic review was conducted on quantitative, qualitative, and mixed-method studies in PsycINFO, PubMed, ScienceDirect, and Cochrane Library databases. Out of the 10,747 articles found, 32 were included. While we aimed to include many cardiac diseases, coronary patients dominated the data. Five main themes emerged: emotional states (depression, anxiety, emotional distress, and stress), quality of life (health-related quality of life, physical functioning, and sexuality), adjusting to the medical environment (coping with the disease, health behavior change, financial barriers, and interactions with medical professionals), social life (social support and work), and identity (parenthood, new challenges, and new meanings). The results highlighted that their levels of depression, anxiety, stress, and quality of life were sometimes worse than in the general population and than in older and younger patients coping with a cardiac illness. Social isolation, identity changes, work, and parenthood were the specific challenges that this population had to face. Furthermore, young adult cardiac patients showed worse health behavior profiles than the general population and felt that they lacked information from professionals, especially regarding sexuality. Compared to men, women had worse psychosocial outcomes, especially regarding depression, stress, emotional distress, and quality of life. Conclusions: Young adult cardiac patients are to be considered with their own identity and challenges. They may be in need of specific interventions, some dedicated to women, and better communication is necessary with their families and professional caregivers so as to improve the patient's mental health, quality of life, coping skills, and adherence.

Females have higher myocardial perfusion, blood volume and extracellular volume compared to males - an adenosine stress cardiovascular magnetic resonance study

Knowledge on sex differences in myocardial perfusion, blood volume (MBV), and extracellular volume (ECV) in healthy individuals is scarce and conflicting. Therefore, this was investigated quantitatively by cardiovascular magnetic resonance (CMR). Healthy volunteers (n = 41, 51% female) underwent CMR at 1.5 T. Quantitative MBV [%] and perfusion [ml/min/g] maps were acquired during adenosine stress and at rest following an intravenous contrast bolus (0.05 mmol/kg, gadobutrol). Native T1 maps were acquired before and during adenosine stress, and after contrast (0.2 mmol/kg) at rest and during adenosine stress, rendering rest and stress ECV maps. Compared to males, females had higher perfusion, ECV, and MBV at stress, and perfusion and ECV at rest (p < 0.01 for all). Multivariate linear regression revealed that sex and MBV were associated with perfusion (sex beta −0.31, p = 0.03; MBV beta −0.37, p = 0.01, model R² = 0.29, p < 0.01) while sex and hematocrit were associated with ECV (sex beta −0.33, p = 0.03; hematocrit beta −0.48, p < 0.01, model R² = 0.54, p < 0.001). Myocardial perfusion, MBV, and ECV are higher in female healthy volunteers compared to males. Sex is an independent contributor to perfusion and ECV, beyond other physiological factors that differ between the sexes. These findings provide mechanistic insight into sex differences in myocardial physiology.

Abnormal P-wave axis and myocardial ischemia development during mental stress

Exposure to psychological stress has been associated with the development of sustained arrhythmias. Acute changes in atrial electrophysiology may serve as intermediate phenotypes for stress-induced atrial arrhythmia such as atrial fibrillation. We examined if acute mental stress was associated with the development of abnormal P-wave axis (aPWA) and the role played by stress-induced myocardial ischemia. A total of 359 patients (mean age = 56 ± 9.9 years; 62% men; 43% white) with stable coronary heart disease and normal baseline P-wave axis (between 0° and 75°) were studied. All patients underwent mental stress testing (speech task). A total of 46 (13%) patients developed abnormal P-wave axis during either stress or recovery (stress: n = 43, 12%; recovery: n = 12, 3%). A rise in heart rate during mental stress was associated with an increased risk of an abnormal P-wave axis (per 5-unit increase: OR = 1.37, 95%CI = 1.03, 1.30). Myocardial ischemia induced by mental stress was associated with an increased risk of aPWA in women (OR = 5.2, 95%CI = 1.7, 15.6) and not in men (OR = 0.1, 95%CI = 0.01, 1.01), p-interaction = 0.004). In conclusion, in a sizable proportion of patients, acute mental stress results in the development of an abnormal P-wave axis, and this phenomenon is related to increases in heart rate and, among women, mental stress-induced ischemia. Our data suggest that acute psychological stress can promote adverse transient electrical changes in the atria that may predispose to AF.

Confederates in the Attic: Posttraumatic Stress Disorder, Cardiovascular Disease, and the Return of Soldier's Heart

Da Costa originally described Soldier's Heart in the 19th Century as a syndrome that occurred on the battlefield in soldiers of the American Civil War. Soldier's Heart involved symptoms similar to modern day posttraumatic stress disorder (PTSD) as well as exaggerated cardiovascular reactivity felt to be related to an abnormality of the heart. Interventions were appropriately focused on the cardiovascular system. With the advent of modern psychoanalysis, psychiatric symptoms became divorced from the body and were relegated to the unconscious. Later, the physiology of PTSD and other psychiatric disorders was conceived as solely residing in the brain. More recently, advances in psychosomatic medicine led to the recognition of mind-body relationships and the involvement of multiple physiological systems in the etiology of disorders, including stress, depression PTSD, and cardiovascular disease, has moved to the fore, and has renewed interest in the validity of the original model of the Soldier's Heart syndrome.

Sex and age differences in the association of heart rate responses to adenosine and myocardial ischemia in patients undergoing myocardial perfusion imaging

BACKGROUND

In light of growing cardiovascular mortality rates observed in young women, sexual dimorphism in cardiac autonomic nervous control is gaining increasing attention. Heart rate responses to adenosine mirror autonomic activity and may carry important prognostic information.

METHODS AND RESULTS

Hemodynamic changes during adenosine stress were retrospectively analysed in a propensity-matched cohort of 1932 consecutive patients undergoing myocardial perfusion single-photon-emission computed tomography (MPI-SPECT). Heart rate (HR) and systolic blood pressure (SBP) increased during adenosine infusion (P < 0.001). The increase in SBP and HR (heart rate reserve, HRR), was significantly more pronounced in women compared with men (P < 0.05). Patients ≤ 55 years had a higher HRR compared with patients > 55 years (46.8% vs 37.5%, P = 0.015). Women ≤ 55 years with a reversible perfusion defect on MPI-SPECT exhibited the highest HRR (89.2%), while age-matched men showed a blunted HR response to adenosine (26.4%, P = 0.01). Accordingly, age and an interaction term of female sex and increased HRR were identified as significant predictors of myocardial ischemia in a multiple regression analysis (OR 1.4, 95% CI 1.02-1.9, P = 0.038).

CONCLUSION

HRR during adenosine infusion is influenced by age and sex. Our data suggest a stronger, sympathetic-driven, hemodynamic response to adenosine in younger women with myocardial ischemia.

Gender in cardiovascular medicine: chest pain and coronary artery disease

Ischaemic heart disease (IHD) remains the leading cause of morbidity and mortality among women and men yet women are more often underdiagnosed, have a delay in diagnosis, and/or receive suboptimal treatment. An implicit gender-bias with regard to lack of recognition of sex-related differences in presentation of IHD may, in part, explain these differences in women compared with men. Indeed, existing knowledge demonstrates that angina does not commonly relate to obstructive coronary artery disease (CAD). Emerging knowledge supports an inclusive approach to chest pain symptoms in women, as well as a more thoughtful consideration of percutaneous coronary intervention for angina in stable obstructive CAD, to avoid chasing our tails. Emerging knowledge regarding the cardiac autonomic nervous system and visceral pain pathways in patients with and without obstructive CAD offers explanatory mechanisms for angina. Interdisciplinary investigation approaches that involve cardiologists, biobehavioural specialists, and anaesthesia/pain specialists to improve angina treatment should be pursued.

Gender Differences in Patient-Reported Outcomes Among Adults With Atherosclerotic Cardiovascular Disease

Background

Atherosclerotic cardiovascular disease (ASCVD) accounts for approximately one third of deaths in women. Although there is an established relationship between positive patient experiences, health‐related quality of life, and improved health outcomes, little is known about gender differences in patient‐reported outcomes among ASCVD patients. We therefore compared gender differences in patient‐centered outcomes among individuals with ASCVD.

Methods and Results

Data from the 2006 to 2015 Medical Expenditure Panel Survey, a nationally representative US sample, were used for this study. Adults ≥18 years with a diagnosis of ASCVD, ascertained by International Classification of Diseases, Ninth Revision (ICD‐9) codes and/or self‐reported data, were included. Linear and logistic regression were used to compare self‐reported patient experience, perception of health, and health‐related quality of life by gender. Models adjusted for demographics, socioeconomic status, and comorbidities. There were 21 353 participants included, with >10 000 (47%‐weighted) of the participants being women, representing ≈11 million female adults with ASCVD nationwide. Compared with men, women with ASCVD were more likely to experience poor patient–provider communication (odds ratio 1.25 [95% confidence interval 1.11–1.41]), lower healthcare satisfaction (1.12 [1.02–1.24]), poor perception of health status (1.15 [1.04–1.28]), and lower health‐related quality of life scores. Women with ASCVD also had lower use of aspirin and statins, and greater odds of ≥2 Emergency Department visits/y.

Conclusions

Women with ASCVD were more likely to report poorer patient experience, lower health‐related quality of life, and poorer perception of their health when compared with men. These findings have important public health implications and require more research towards understanding the gender‐specific differences in healthcare quality, delivery, and ultimately health outcomes among individuals with ASCVD.

Young Women With Coronary Artery Disease Exhibit Higher Concentrations of Interleukin-6 at Baseline and in Response to Mental Stress

Background

Young women with coronary artery disease (CAD), a group with high psychosocial burden, were previously shown to have higher levels of interleukin‐6 (IL‐6) compared with men of similar age. We sought to examine IL‐6 response to acute stress in CAD patients across sex and age, and contrast results to healthy controls and other biomarkers known to increase with mental stress (monocyte chemoattractant protein‐1 and matrix metallopeptidase‐9) and known limited stress‐reactivity (high‐sensitivity C‐reactive protein).

Methods and Results

Inflammatory biomarkers were measured at rest and 90 minutes after mental stress (speech task) among 819 patients with CAD and 89 healthy controls. Repeated‐measures models were used to investigate age (continuous) and sex differences across time, before and after adjusting for demographics, CAD risk factors, depressive symptoms, medication use, and CAD severity. Among patients with CAD, the mean age was 60 years (range, 25–79) and 31% were women. Younger women with CAD had significantly higher concentrations of IL‐6 at rest, 90 minutes after mental stress, as well as a higher response to stress, compared with similarly aged men (P<0.05 for sex by age interactions). In contrast, IL‐6 increased with age, and there were no sex differences in IL‐6 levels or response to stress among controls. Inflammatory responses to stress for high‐sensitivity C‐reactive protein, monocyte chemoattractant protein‐1, and matrix metallopeptidase‐9 among CAD patients were similar in women and men.

Conclusions

IL‐6 response to mental stress are higher in young women with CAD than men of similar age.

Effects of a mental stress challenge on brain function in coronary artery disease patients with and without depression

OBJECTIVE

Coronary artery disease (CAD) patients with comorbid depression show an increase in mortality compared to cardiac patients without depression, but the mechanisms mediating this effect remain obscure. One possible explanation for this finding is that depressed patients with CAD exhibit an increased vulnerability to stress. The purpose of this study was to assess the effects of stress and depression on brain function and to explore its relationship with myocardial ischemia in CAD patients.

METHODS

Patients with CAD and depression (N = 13) and CAD without depression (N = 15) underwent imaging of the brain with positron emission tomography and [O-15] water and imaging of the heart with single photon emission computed tomography (SPECT) and [Tc-99m] sestamibi under mental stress task and control conditions.

RESULTS

CAD patients with depression compared to nondepressed showed decreased function with mental stress in the rostral anterior cingulate, the hippocampus, parts of the dorsolateral temporal and parietal cortex, the cerebellum, and the uncus, with increased blood flow in the parahippocampus, visual association cortex, and posterior cingulate. Depressed CAD patients who became ischemic during a mental stress task had relative decreases in the caudal and posterior cingulate, orbitofrontal cortex, and cerebellum, and increased activation in the parietal cortex and precuneus/visual association cortex compared to nonischemic depressed CAD patients.

CONCLUSIONS

These findings are consistent with dysfunction in a network of brain regions involved in the stress response in patients with comorbid CAD and depression that has direct and indirect links to the heart, suggesting a pathway by which stress and depression could lead to increased risk of heart disease related morbidity and mortality. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Longitudinal associations between self-reported experiences of discrimination and depressive symptoms in young women and men post- myocardial infarction

Objectives

Research suggests that following a myocardial infarction (MI), women under the age of 60 have more elevated depressive symptoms and adverse outcomes than similarly aged men. Identifying risk factors that contribute to gender differences in depressive symptoms among this group may be critical to the development of psychosocial interventions. Experiences of discrimination may be an important correlate of depressive symptoms in this group; however, studies of this relationship have largely been cross-sectional and focused on healthy populations. This study examines longitudinal associations among gender, discrimination, and depressive symptoms in a young post-MI cohort.

Methods

Participants were 313 adults from the Myocardial Infarction and Mental Stress Ischemia Study 2 of young (≤60 yrs) post-MI patients. At baseline and 6 month follow-up, depressive symptoms were measured with the Beck Depression Inventory-II and discrimination was assessed with the 10-item version Everyday Discrimination scale. Linear regression models were used to assess the longitudinal association between reports of discrimination and depressive symptoms adjusted for sociodemographic characteristics, psychosocial factors and health status indicators and tested for gender differences.

Results

The mean age was 51.2, 49.6% were women, and 69.5% were African-American. Although the discrimination-by-gender interaction was marginally significant (p=.09) in the fully adjusted model, findings suggest that the association between changes in reports of discrimination and depressive symptoms over time may be more pronounced for women (β=.61, standard error=.15, p<.001) than men (β=.27, standard error=.13, p=.033).

Conclusion

Our findings suggest that discrimination is a risk factor for depressive symptoms in young post-MI populations over time.

Sex differences in brain activation patterns with mental stress in patients with coronary artery disease

Background

Stress is an important contributor to myocardial ischemia and the progression of coronary artery disease (CAD), and women are more susceptible than men to these effects. Little is known, however, about the neural basis of these sex differences.

Methods

We investigated sex differences in neural correlates of mental stress in a sample of 53 female and 112 male participants (N = 165) with CAD, with and without mental stress-induced myocardial ischemia (MSI), during exposure to mental arithmetic tasks and public speaking stress tasks using high-resolution positron emission tomography (HR-PET) and radiolabeled water imaging of the brain.

Results

Women compared to men had significantly greater activation with stress in the right frontal (BA 9, 44), right parietal lobe (Area 3, 6, 40), right posterior cingulate gyrus (BA 31), bilateral cerebellum, and left temporal/fusiform gyrus (BA 37) and greater deactivation in bilateral anterior cingulate gyrus (BA 24, 32), bilateral medial frontal gyrus (BA 6, 8, 9, 10), right parahippocampal gyrus, and right middle temporal gyrus (BA 21). Women with MSI (but not those without MSI) showed significantly greater activation than men in the right posterior cingulate gyrus (BA 31) and greater deactivation in several frontal and temporal lobe areas.

Conclusion

Men and women with CAD show differences in responses to stress in brain limbic areas that regulate emotion, and these functional responses differ by MSI status. Our results suggest that the cingulate gyrus may be involved in sex differences in MSI.

Electronic supplementary material

The online version of this article (10.1186/s13293-019-0248-4) contains supplementary material, which is available to authorized users.

Early childhood trauma alters neurological responses to mental stress in patients with coronary artery disease

BACKGROUND

Early childhood trauma is known to independently increase adverse outcome risk in coronary artery disease (CAD) patients, although the neurological correlates are not well understood. The purpose of this study was to examine whether early childhood trauma alters neural responses to acute mental stress in CAD patients.

METHODS

Participants (n = 152) with CAD underwent brain imaging with High Resolution Positron Emission Tomography and radiolabeled water during control (verbal counting, neutral speaking) and mental stress (mental arithmetic, public speaking). Traumatic events in childhood were assessed with the Early Trauma Inventory (ETI-SR-SF) and participants were separated by presence (ETI+) or absence (ETI-) of early childhood trauma. Brain activity during mental stress was compared between ETI+ and ETI-.

RESULTS

Compared to ETI-, ETI+ experienced greater (p < 0.005) activations during mental stress within the left anterior cingulate, bilateral frontal lobe and deactivations (p < 0.005) within the left insula, left parahippocampal gyrus, right dorsal anterior cingulate, bilateral cerebellum, bilateral fusiform gyrus, left inferior temporal gyrus, and right parietal lobe. Significant (p < 0.005) positive correlations between brain activation and ETI-SR-SF scores were observed within the left hippocampus, bilateral frontal lobe, left occipital cuneus, and bilateral temporal lobe.

LIMITATIONS

Results in non-CAD samples may differ and ETI may be subject to recall bias.

CONCLUSION

Early childhood trauma exacerbated activations in stress-responsive limbic and cognitive brain areas with direct and indirect connections to the heart, potentially contributing to adverse outcomes in CAD patients.

Brain Correlates of Mental Stress-Induced Myocardial Ischemia

OBJECTIVE

Coronary artery disease (CAD) is a major cause of morbidity and mortality, and despite important advances in our understanding of this disorder, the underlying mechanisms remain under investigation. Recently, increased attention has been placed on the role of behavioral factors such as emotional stress on CAD risk. Brain areas involved in memory and the stress response, including medial prefrontal cortex, insula, and parietal cortex, also have outputs to the peripheral cardiovascular system. The purpose of this study was to assess the effects of mental stress on brain and cardiac function in patients with CAD.

METHODS

CAD patients (N = 170) underwent cardiac imaging with [Tc-99m] sestamibi single-photon emission tomography at rest and during a public speaking mental stress task. On another day, they underwent imaging of the brain with [O-15] water positron emission tomography (PET) during mental stress (arithmetic and public speaking) and control conditions.

RESULTS

Patients with mental stress-induced myocardial ischemia showed increased activation with stress in anterior cingulate, inferior frontal gyrus, and parietal cortex (p < .005). This was seen with both arithmetic stress and public speaking stress. Arithmetic stress was additionally associated with left insula activation, and public speaking with right pre/postcentral gyrus and middle temporal gyrus activation (p < .005).

CONCLUSIONS

These findings suggest that mental stress-induced myocardial ischemia is associated with activation in brain areas involved in the stress response and autonomic regulation of the cardiovascular system. Altered brain reactivity to stress could possibly represent a mechanism through which stress leads to increased risk of CAD-related morbidity and mortality.

The Relation of Psychosocial Distress With Myocardial Perfusion and Stress-Induced Myocardial Ischemia

OBJECTIVE

Mental stress-induced myocardial ischemia is a frequent phenomenon in patients with coronary artery disease (CAD). The link between an integrated measure of chronic psychosocial distress and mental stress-induced myocardial ischemia, and whether it differs by sex, has not been examined before.

METHODS

We used latent class analysis to derive a composite measure of psychosocial distress integrating scales of depression, posttraumatic stress, anxiety, anger, hostility, and perceived stress in 665 individuals with stable CAD. Participants underwent myocardial perfusion imaging with mental stress and perfusion defects were quantified at rest (summed rest score), with mental stress (summed stress score), and their difference (summed difference score), the latter being an index of inducible ischemia.

RESULTS

The M (SD) age was 63 (9) years, and 185 (28%) were women. Latent class analysis characterized the study sample into four distinct classes of incremental psychosocial distress. In women, class 4 (highest distress) had an adjusted 4.0-point higher summed rest score (95% confidence interval = 0.2-7.7) as compared with class 1 (lowest distress), whereas no difference was observed in men (-0.87 points, 95% confidence interval = -3.74 to 1.99, p = .04 for interaction). There was no association between the psychosocial distress latent variable and summed difference score in either women or men.

CONCLUSIONS

Among patients with CAD, a higher level of psychosocial distress is not associated with mental stress ischemia, but it is associated with more resting (fixed) perfusion abnormalities in women only, as well as with blunted hemodynamic response to mental stress in both men and women.

Emerging misunderstood presentations of cardiovascular disease in young women

BACKGROUND

Cardiovascular disease (CVD) remains the leading cause of death for females in the United States accounting for over 412 000 female deaths in 2016. CVD mortality in young women <55 years old remains significantly high and greater than that in men.

HYPOTHESIS

There is a void with regards to awareness of CVD in women. Many traditional CVD risk estimate tools fail to identify the "at risk" female and is true for the young female patient. There needs to be a shift in focus from looking for the vulnerable plaque to looking for the "at risk" patient.

METHODS

This review outlines the emerging misunderstood presentations of CVD in young women which include certain categories of myocardial infarction (MI) with non-obstructive coronary arteries (MINOCA), such as spontaneous coronary artery dissection (SCAD), as well as the more stable myocardial ischemia with non-obstructive coronary arteries (INOCA) category focusing on mental stress-induced myocardial ischemia (MSIMI).

RESULTS

The prevalence of MINOCA in patients presenting with MI is greater in women. In younger women with CVD, SCAD is an emerging misunderstood presentation in this group of patients with type 2 SCAD being the most common form. MSIMI, a form of INOCA, is more common in women with CVD.

CONCLUSIONS

There are emerging misunderstood factors that are prevalent in young women, such as SCAD and MSIMI. It is important to recognize their presentations in young women to prevent misdiagnosis, missed diagnosis as well as mismanagement of these patients to improve their clinical outcomes.

Clarifying the Concept of Depression in Women With Coronary Heart Disease

The concept of depression in women with coronary heart disease has been poorly defined for several reasons: numerous widely variable instruments that operationalize the concept, divergent proposed instrument cutoff scores, and continued lack of female participants and data analysis by gender in coronary heart disease research. In the forty articles from 1990 to 2018 evaluating depression in women with coronary heart disease, the concept is defined by specific somatic and cognitive symptoms, preceded by particular physiological and psychosocial vulnerabilities, and leads to poorer outcomes. Concept clarification is necessary for accurate diagnosis of depression, leading to more timely and appropriate interventions for women.

Neighborhood Environment and DNA Methylation: Implications for Cardiovascular Disease Risk

Exposure to chronic stress such as living in disadvantaged neighborhoods has been related to cardiovascular disease (CVD). Chronic stress may increase the risk for CVD by increasing levels of systemic inflammation (e.g., higher levels of pro-inflammatory cytokines). Differential DNA methylation of inflammation-related candidate genes is also related to higher risk for CVD. Thus, the purpose of this review was to examine the association of neighborhood disadvantage with DNA methylation. A search of literature was conducted using Scopus, CINAHL, PubMed, Medline, and Embase databases. The keywords neighborhood, neighborhood disorder, neighborhood crime, neighborhood violence, neighborhood safety, built environment, and housing vacancy were combined with the keywords DNA methylation and epigenetics. Five studies were included in this review (n = 3 adult blood samples and n = 2 fetal blood samples). Four of the five studies reported an association of neighborhood socioeconomic status, social environment, and crime with either global or gene-specific DNA methylation. Only two studies examined the association of neighborhood disadvantage with inflammation-related candidate genes. One of these studies found a significant association of neighborhood socioeconomic disadvantage and social environment with DNA methylation in inflammation-related candidate genes. Thus, data are limited on the association between neighborhood disadvantage and DNA methylation of inflammation-related candidate genes, as well as genes in other potential mechanistic pathways including psychosocial stress, toxin response, and adiposity. Future studies should examine these associations and the potential epigenetic mechanisms by which neighborhood disadvantage increases the risk for CVD.

Neighborhood poverty and hemodynamic, neuroendocrine, and immune response to acute stress among patients with coronary artery disease

Living in neighborhoods characterized by poverty may act as a chronic stressor that results in physiological dysregulation of the sympathetic nervous system. No previous study has assessed neighborhood poverty with hemodynamic, neuroendocrine, and immune reactivity to stress. We used data from 632 patients with coronary artery disease. Patients' residential addresses were geocoded and merged with poverty data from the 2010 American Community Survey at the census-tract level. A z-transformation was calculated to classify census tracts (neighborhoods) as either having 'high' or 'low' poverty. Systolic blood pressure, diastolic blood pressure, heart rate, rate-pressure product, epinephrine, interleukin-6, and high-sensitivity C-reactive protein were measured before and after a public speaking stress task. Multilevel models were used for repeated measures and accounting for individuals nested within census tracts. Adjusted models included demographics, lifestyle and medical risk factors, and medication use. Another set of models included propensity scores weighted by the inverse probability of neighborhood status for sex, age, race, and individual-level income. The mean age was 63 years and 173 were women. After adjusting for potential confounders, participants living in high (vs. low) poverty neighborhoods had similar hemodynamic values at rest and lower values during mental stress for systolic blood pressure (157 mmHg vs. 161 mmHg; p = 0.07), heart rate (75 beats/min vs. 78 beats/min; p = 0.02) and rate-pressure product (11839 mmHg x beat/min vs 12579 mmHg x beat/min; p = 0.01). P-values for neighborhood poverty-by-time interactions were <0.05. Results were similar in the propensity weighted models. There were no significant differences in inflammatory and epinephrine responses to mental stress based on neighborhood poverty status. A blunted hemodynamic response to mental stress was observed among participants living in high poverty neighborhoods. Future studies should explore whether neighborhood poverty and blunted hemodynamic response to stress translate into differences in long-term cardiovascular outcomes.

Sex-Specific Association Between Coronary Artery Disease Severity and Myocardial Ischemia Induced by Mental Stress

OBJECTIVE

It is unclear whether mental stress-induced myocardial ischemia (MSIMI) is related to obstructive coronary artery disease (CAD). We examined this question and contrasted results with ischemia induced by conventional stress testing (CSIMI). Because women are more susceptible to ischemia without coronary obstruction than men, we examined sex differences.

METHODS

We studied 276 patients 61 years and younger with recent myocardial infarction. CAD severity was quantified using the log-transformed Gensini Score (lnGS) and the Sullivan Stenosis Score. Patients underwent myocardial perfusion imaging with mental stress (public speaking) and conventional (exercise or pharmacological) stress testing. MSIMI and CSIMI were defined as a new or worsening perfusion defect.

RESULTS

The prevalence of MSIMI was 15% in men and 20% in women. The median GS for patients with MSIMI was 65.0 in men and 28.5 in women. In logistic regression models adjusted for demographic and cardiovascular risk factors, CAD severity was associated with CSIMI in the full sample (odds ratio [OR] = 1.49, 95% [CI], 1.14-1.95, per 1-unit increase in lnGS), with no significant difference by sex. Although CAD severity was not associated with MSIMI in the entire sample, results differed by sex. CAD severity was associated with MSIMI among men (OR = 1.95, 95% CI, 1.13-3.36, per 1-unit increase in lnGS), but not among women (OR = 1.02, 95% CI, 0.74-1.42, p = .042 for interaction). Analysis using Sullivan Stenosis Score yielded similar results.

CONCLUSIONS

Findings suggest that CAD severity is related to MSIMI in men but not women. MSIMI in women may therefore be driven by alternative mechanisms such as coronary microvascular disease.

Use of High-Sensitivity Cardiac Troponin for the Exclusion of Inducible Myocardial Ischemia: A Cohort Study

BACKGROUND

Many patients with coronary artery disease (CAD) are routinely referred for surveillance stress testing despite recommendations against it.

OBJECTIVE

To determine whether low levels of resting high-sensitivity cardiac troponin I (hs-cTnI) can identify persons without inducible myocardial ischemia.

DESIGN

Observational study.

SETTING

A university-affiliated hospital network.

PATIENTS

Persons with stable CAD: 589 in the derivation group and 118 in the validation cohort.

MEASUREMENTS

Presence of inducible myocardial ischemia was determined by myocardial perfusion imaging with technetium-99m single-photon emission computed tomography during either treadmill or pharmacologic stress testing. Resting plasma hs-cTnI was measured within 1 week of the stress test, and the negative predictive value (NPV) for inducible ischemia was calculated. The derivation cohort was followed for 3 years for incident cardiovascular death and myocardial infarction.

RESULTS

In the derivation cohort, 10 of 101 patients with an hs-cTnI level below 2.5 pg/mL had inducible myocardial ischemia (NPV, 90% [95% CI, 83% to 95%]) and 3 of 101 had inducible ischemia involving at least 10% of the myocardium (NPV, 97% [CI, 92% to 99%]). In the validation cohort, 4 of 32 patients with an hs-cTnI level below 2.5 pg/mL had inducible ischemia (NPV, 88% [CI, 71% to 96%]) and 2 of 32 had ischemia of 10% or greater (NPV, 94% [CI, 79% to 99%]). After a median follow-up of 3 years in the derivation cohort, no adverse events occurred in patients with an hs-cTnI level below 2.5 pg/mL, compared with 33 (7%) cardiovascular deaths or incident myocardial infarctions among those with an hs-cTnI level of 2.5 pg/mL or greater.

LIMITATION

The data may not be applicable to a population without known CAD or to persons with unstable angina, and the modest sample sizes warrant further validation in a larger cohort.

CONCLUSION

Very low hs-cTnI levels may be useful in excluding inducible myocardial ischemia in patients with stable CAD.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Gender Differences in Associations Between Stress and Cardiovascular Risk Factors and Outcomes

Psychological stress, a subjective perception of an adverse environmental change, is a hallmark of modern society. Although psychological stress has previously been established as a risk factor for cardiovascular disease (CVD), it is unclear whether stress influences cardiovascular risk differently in men versus women. Gender disparities exist in the prevalence of stress as well as in the prevalence and prognosis of CVD; therefore, associations between stress and CVD risk and mortality may vary by sex. The purpose of this review was to summarize the evidence from recent and landmark studies on gender differences in the associations of stress with CVD risk factors and end points and to highlight clinical and public health implications as well as future research directions in this field. Taken together, research to date indicates that while stress is associated with poorer cardiovascular health metrics in both men and women, the influence of stress on measures of glucose regulation and dyslipidemia and on overall CVD risk may be stronger among women. However, men may be more susceptible to the influence of stress on body adiposity, blood pressure, and CVD mortality. In terms of behavioral risk factors for CVD, associations between stress and diet quantity and quality appear to be stronger among women, but the influence of stress on sedentary behaviors and sleep may be stronger among men. Given that gender disparities exist in the prevalence of overall and different types of stress (eg, financial stress, caregiving stress, and occupational stress), future studies should decipher the potential differential associations between types of stress and cardiovascular risk among men and women to identify vulnerable populations and develop targeted interventions.

Age- and sex-dependent changes in sympathetic activity of the left ventricular apex assessed by 18F-DOPA PET imaging

BACKGROUND

Sexual dimorphism in cardiac sympathetic outflow has recently gained attention in the context of Takotsubo cardiomyopathy. Previous studies suggest that there are sex- and age-dependent differences in peripheral autonomic control, however, data on cardiac-specific sympathetic activation in aged women and men are lacking.

METHODS AND RESULTS

Regional quantitative analysis of cardiac fluorine-18 (18F)- Dihydroxyphenylalanine (DOPA) uptake was retrospectively performed in 133 patients (69 females, mean age 52.4±17.7 years) referred for assessment of neuroendocrine tumours (NET) by Positron-Emission-Tomography. Cardiac 18F-DOPA uptake was significantly higher in women as compared to men (1.33±0.21 vs. 1.18±0.24, p<0.001). This sex-difference was most pronounced in the apical region of the left ventricle (LV, 1.30±0.24 in women vs. 1.13±0.25 in men, p<0.001) and in individuals >55 years of age (1.39±0.25 in women vs. 1.09±0.24 in men, p<0.001). Women showed a prominent increase in myocardial 18F-DOPA uptake with age with the strongest increase seen in the LV apical region (r = 0.34, p = 0.004). Accordingly, sex and age were selected as significant predictors of LV apical 18F-DOPA uptake in a stepwise linear regression model. No age-dependent changes of cardiac 18F-DOPA uptake were observed in men or in the right ventricular region.

CONCLUSION

Our study suggests that aging is related to sex-specific changes in regional cardiac sympathetic activity. Future studies will have to assess whether the increase in LV apical 18F-DOPA uptake with age in women is of pathogenic relevance for the higher susceptibility of postmenopausal women to conditions associated with increased sympathetic activity.

Sex differences in the long-term prognostic value of 13N-ammonia myocardial perfusion positron emission tomography

PURPOSE

Evidence to date on the unique female determinants of cardiovascular risk is inadequate. Positron Emission Tomography (PET) is considered to have the highest accuracy for the assessment of myocardial perfusion in patients with suspected coronary artery disease (CAD), but its long-term prognostic accuracy in women has not been established.

METHODS

A total of 619 consecutive patients (138 women, mean age 60.0 ± 11.8 years) underwent clinically indicated ¹³N-ammonia PET at our institution and were followed up (median 5.7 years) for major adverse cardiovascular events (MACE) including cardiac death, nonfatal myocardial infarction, hospitalization for any cardiac reason and late revascularization.

RESULTS

During follow-up, 271 patients had at least one cardiac event, including 64 cardiac deaths and 33 nonfatal myocardial infarctions. In both women and men, abnormal myocardial perfusion was associated with reduced event-free survival (log rank p < 0.001). In women, abnormal myocardial perfusion was associated with a higher risk of a worse outcome than in men (adjusted HR 4.1, 95% CI 1.8-9.0 in women; HR 2.4, 95% CI 1.5-3.8 in men; p_interaction < 0.001). In contrast, abnormal coronary flow reserve (CFR) was a significant predictor of 10-year MACE in men (p = 0.006) but not in women (p = NS). Accordingly, an interaction term of sex and abnormal myocardial perfusion or CFR was significant (p < 0.001).

CONCLUSION

While perfusion findings in ¹³N-ammonia PET provide effective risk stratification in women and men, CFR adds incremental prognostic value for long-term cardiac outcomes only in men. Refined strategies in noninvasive imaging are needed in women to improve CAD risk prediction.

Coronary and Peripheral Vasomotor Responses to Mental Stress

Background

Coronary microvascular dysfunction may contribute to myocardial ischemia during mental stress (MS). However, the role of coronary epicardial and microvascular function in regulating coronary blood flow (CBF) responses during MS remains understudied. We hypothesized that coronary vasomotion during MS is dependent on the coronary microvascular endothelial function and will be reflected in the peripheral microvascular circulation.

Methods and Results

In 38 patients aged 59±8 years undergoing coronary angiography, endothelium‐dependent and endothelium‐independent coronary epicardial and microvascular responses were measured using intracoronary acetylcholine and nitroprusside, respectively, and after MS induced by mental arithmetic testing. Peripheral microvascular tone during MS was measured using peripheral arterial tonometry (Itamar Inc, Caesarea, Israel) as the ratio of digital pulse wave amplitude compared to rest (peripheral arterial tonometry ratio). MS increased the rate‐pressure product by 22% (±23%) and constricted epicardial coronary arteries by −5.9% (−10.5%, −2.6%) (median [interquartile range]), P=0.001, without changing CBF. Acetylcholine increased CBF by 38.5% (8.1%, 91.3%), P=0.001, without epicardial coronary diameter change (0.1% [−10.9%, 8.2%], P=not significant). The MS‐induced CBF response correlated with endothelium‐dependent CBF changes with acetylcholine (r=0.38, P=0.03) but not with the response to nitroprusside. The peripheral arterial tonometry ratio also correlated with the demand‐adjusted change in CBF during MS (r=−0.60, P=0.004), indicating similarity between the microcirculatory responses to MS in the coronary and peripheral microcirculation.

Conclusions

The coronary microvascular response to MS is determined by endothelium‐dependent, but not endothelium‐independent, coronary microvascular function. Moreover, the coronary microvascular responses to MS are reflected in the peripheral microvascular circulation.

Chest Pain and Mental Stress-Induced Myocardial Ischemia: Sex Differences

BACKGROUND

Mental stress-induced myocardial ischemia is a frequent phenomenon in patients with coronary artery disease. Women with coronary artery disease tend to have more mental stress-induced myocardial ischemia and more chest pain/anginal symptoms than men, but whether the association between mental stress-induced myocardial ischemia and angina burden differs in women and men is unknown.

METHODS

This was a cross-sectional study with experimental manipulation of 950 individuals with stable coronary artery disease. Chest pain/angina frequency in the previous 4 weeks was assessed with the Seattle Angina Questionnaire's angina-frequency subscale. Mental stress-induced myocardial ischemia was assessed with myocardial perfusion imaging during mental stress (standardized public speaking task). Presence of mental stress-induced myocardial ischemia was based on expert readers and established criteria. A conventional (exercise or pharmacologic) stress test was used as a control condition.

RESULTS

Overall, 338 individuals (37%) reported angina; 112 (12%) developed mental stress-induced myocardial ischemia, and 256 (29%) developed conventional stress ischemia. Women who reported angina had almost double the probability to develop mental stress-induced myocardial ischemia (19% vs 10%, adjusted prevalence rate ratio, 1.90; 95% confidence interval, 1.04-3.46), whereas there was no such difference in men (11% vs 11%, adjusted prevalence rate ratio, 1.09; 95% confidence interval, 0.66-1.82). No association was found between angina symptoms and conventional stress ischemia for women or men. Results for ischemia as a continuous variable were similar.

CONCLUSIONS

In women, but not in men, anginal symptoms may be a marker of vulnerability toward ischemia induced by psychologic stress. These results highlight the psychosocial origins of angina in women and may have important implications for the management and prognosis of women with angina.

Weather and risk of ST-elevation myocardial infarction revisited: Impact on young women

Background

During the last decade, the incidence and mortality rates of ST-elevation myocardial infarction (STEMI) has been steadily increasing in young women but not in men. Environmental variables that contribute to cardiovascular events in women remain ill-defined.

Methods and results

A total of 2199 consecutive patients presenting with acute ST-elevation myocardial infarction (STEMI, 25.8% women, mean age 62.6±12.4 years) were admitted at the Montreal Heart Institute between June 2010 and December 2014. Snow fall exceeding 2cm/day was identified as a positive predictor for STEMI admission rates in the overall population (RR 1.28, 95% CI 1.07–1.48, p = 0.005), with a significant effect being seen in men (RR 1.30, 95% CI 1.06–1.53, p = 0.01) but not in women (p = NS). An age-specific analysis revealed a significant increase in hospital admission rates for STEMI in younger women ≤55 years, (n = 104) during days with higher outside temperature (p = 0.004 vs men ≤55 years) and longer daylight hours (p = 0.0009 vs men ≤55 years). Accordingly, summer season, increased outside temperature and sunshine hours were identified as strong positive predictors for STEMI occurrence in women ≤55 years (RR 1.66, 95% CI 1.1–2.5, p = 0.012, RR 1.70, 95% CI 1.2–2.5, p = 0.007, and RR 1.67, 95% CI 1.2–2.5, p = 0.011, respectively), while an opposite trend was observed in men ≤55 years (RR for outside temperature 0.8, 95% CI 0.73–0.95, p = 0.01).

Conclusion

The impact of environmental variables on STEMI is age- and sex-dependent. Higher temperature may play an important role in triggering such acute events in young women.

Mental Stress-Induced-Myocardial Ischemia in Young Patients With Recent Myocardial Infarction: Sex Differences and Mechanisms

BACKGROUND

Mental stress-induced myocardial ischemia (MSIMI) is frequent in patients with coronary artery disease and is associated with worse prognosis. Young women with a previous myocardial infarction (MI), a group with unexplained higher mortality than men of comparable age, have shown elevated rates of MSIMI, but the mechanisms are unknown.

METHODS

We studied 306 patients (150 women and 156 men) ≤61 years of age who were hospitalized for MI in the previous 8 months and 112 community controls (58 women and 54 men) frequency matched for sex and age to the patients with MI. Endothelium-dependent flow-mediated dilation and microvascular reactivity (reactive hyperemia index) were measured at rest and 30 minutes after mental stress. The digital vasomotor response to mental stress was assessed using peripheral arterial tonometry. Patients received 99mTc-sestamibi myocardial perfusion imaging at rest, with mental (speech task) and conventional (exercise/pharmacological) stress.

RESULTS

The mean age of the sample was 50 years (range, 22-61). In the MI group but not among controls, women had a more adverse socioeconomic and psychosocial profile than men. There were no sex differences in cardiovascular risk factors, and among patients with MI, clinical severity tended to be lower in women. Women in both groups showed a higher peripheral arterial tonometry ratio during mental stress but a lower reactive hyperemia index after mental stress, indicating enhanced microvascular dysfunction after stress. There were no sex differences in flow-mediated dilation changes with mental stress. The rate of MSIMI was twice as high in women as in men (22% versus 11%, P=0.009), and ischemia with conventional stress was similarly elevated (31% versus 16%, P=0.002). Psychosocial and clinical risk factors did not explain sex differences in inducible ischemia. Although vascular responses to mental stress (peripheral arterial tonometry ratio and reactive hyperemia index) also did not explain sex differences in MSIMI, they were predictive of MSIMI in women only.

CONCLUSIONS

Young women after MI have a 2-fold likelihood of developing MSIMI compared with men and a similar increase in conventional stress ischemia. Microvascular dysfunction and peripheral vasoconstriction with mental stress are implicated in MSIMI among women but not among men, perhaps reflecting women's proclivity toward ischemia because of microcirculatory abnormalities.

Myocardial Ischemia and Mobilization of Circulating Progenitor Cells

Background

The response of progenitor cells (PCs) to transient myocardial ischemia in patients with coronary artery disease remains unknown. We aimed to investigate the PC response to exercise‐induced myocardial ischemia (ExMI) and compare it to flow mismatch during pharmacological stress testing.

Methods and Results

A total of 356 patients with stable coronary artery disease underwent 99mTc‐sestamibi myocardial perfusion imaging during exercise (69%) or pharmacological stress (31%). CD34⁺ and CD34⁺/chemokine (C‐X‐C motif) receptor 4 PCs were enumerated by flow cytometry. Change in PC count was compared between patients with and without myocardial ischemia using linear regression models. Vascular endothelial growth factor and stromal‐derived factor‐1α were quantified. Mean age was 63±9 years; 76% were men. The incidence of ExMI was 31% and 41% during exercise and pharmacological stress testing, respectively. Patients with ExMI had a significant decrease in CD34⁺/chemokine (C‐X‐C motif) receptor 4 (−18%, P=0.01) after stress that was inversely correlated with the magnitude of ischemia (r=−0.19, P=0.003). In contrast, patients without ExMI had an increase in CD34⁺/chemokine (C‐X‐C motif) receptor 4 (14.7%, P=0.02), and those undergoing pharmacological stress had no change. Plasma vascular endothelial growth factor levels increased (15%, P<0.001) in all patients undergoing exercise stress testing regardless of ischemia. However, the change in stromal‐derived factor‐1α level correlated inversely with the change in PC counts in those with ExMI (P=0.03), suggesting a greater decrease in PCs in those with a greater change in stromal‐derived factor‐1α level with exercise.

Conclusions

ExMI is associated with a significant decrease in circulating levels of CD34⁺/chemokine (C‐X‐C motif) receptor 4 PCs, likely attributable, at least in part, to stromal‐derived factor‐1α–mediated homing of PCs to the ischemic myocardium. The physiologic consequences of this uptake of PCs and their therapeutic implications need further investigation.

Taking cardiology clinical trials to the next level: A call to action

Physicians previously perceived heart disease to be a man's disease; yet, since 1984, more women have died of ischemic heart disease. Because women who develop obstructive coronary heart disease and heart failure tend to do so 10 years later than men, cardiology clinical trials that use arbitrary age cutoffs or exclusion criteria based on comorbidities and polypharmacy often limit the pool of potential participants to a greater extent for women. Issues related to trial design and insufficient accounting for female-predominant disease patterns have contributed to low rates of enrollment of women in certain domains of cardiology research. Accordingly, women do not benefit from as rich an evidence base for cardiology as men. Here, we review major sex differences in heart disease and discuss areas of cardiology research in which women have been underrepresented. Considering the widespread sex differences in cardiovascular structure and function, it is important to include balanced numbers of women and men in cardiovascular clinical trials. Beyond inclusion, sex-specific reporting is also essential. Moreover, with ongoing developments of clinical-trial methodology, it is imperative to seek innovative ways to learn as much as possible about how interventions behave in women and men. Adaptive trials are specifically identified as promising opportunities to consider sex-based analyses at interim stages, allowing sex-specific flexibility as these trials unfold. Finally, we emphasize the importance of factoring sex as a biological variable into the design, analysis, and reporting of preclinical research, because this research critically informs the design and execution of clinical trials.

Psychological Factors and Their Association with Ideal Cardiovascular Health Among Women and Men

BACKGROUND

The cardiovascular effects of stress and other psychological factors may be different between women and men. We assessed whether self-perceived adverse psychological factors were associated with achievement of ideal cardiovascular health (CVH) as measured by the American Heart Association's Life's Simple Seven (LS7) and whether this differed by sex.

METHODS

This was a cross-sectional study of employees from a large healthcare organization. The LS7 metrics (smoking, physical activity, diet, body mass index, blood pressure, cholesterol, and glucose) were each scored as ideal (2), intermediate (1), or poor (0). Total scores were categorized as optimal (11-14), average (9-10), and inadequate (0-8). Using logistic regression, we tested whether psychological factors obtained by questionnaire (self-perceived stress, low life satisfaction, hopelessness, sadness, depression, and anxiety) were associated with CVH, after adjustment for age, ethnicity, and education.

RESULTS

Among 9,056 participants, the mean (SD) age was 43 (12) years, 74% were women, 57% Hispanic/Latino, 17% white, and 16% black. Stress was associated with reduced odds of having optimal/average CVH [OR 0.58 (95% CI 0.50-0.66) and 0.63 (0.50-0.81), for women and men, respectively]. Similarly, depression was associated with reduced odds of optimal/average CVH [0.58 (0.43-0.78) and 0.44 (0.26-0.76), for women and men, respectively]. Low life satisfaction, hopelessness, sadness, and anxiety were also associated with statistically significantly lower odds of optimal/average CVH in women, but not in men; however, there were no interactions by sex.

CONCLUSIONS

In an ethnically diverse population, both women and men with several adverse self-perceived psychological factors were less likely to have optimal or adequate CVH. Future studies are needed to determine whether addressing psychological stressors can improve CVH.

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.

Hemodynamic, catecholamine, vasomotor and vascular responses: Determinants of myocardial ischemia during mental stress

AIMS

Mental stress-induced myocardial ischemia (MSIMI) in patients with coronary artery disease (CAD) is associated with adverse cardiovascular outcomes. We aim to assess hemodynamic, neuro-hormonal, endothelial, vasomotor and vascular predictors of MSIMI.

METHODS AND RESULTS

We subjected 660 patients with stable CAD to 99mTc sestamibi myocardial perfusion imaging at rest, with mental (speech task) and with conventional (exercise/pharmacological) stress. Endothelium-dependent flow-mediated dilation (FMD), microvascular reactivity [reactive hyperemia index (RHI)] and arterial stiffness [pulse wave velocity (PWV)] were measured at rest and 30-min after mental stress. The digital microvascular vasomotor response during mental stress was assessed using peripheral arterial tonometry (PAT). A total of 106(16.1%) patients had MSIMI. Mental stress was accompanied by significant increases in rate-pressure-product (heart rate x systolic blood pressure; RPP), epinephrine levels and PWV, and significant decreases in FMD and PAT ratio denoting microvascular constriction. In comparison to those with no MSIMI, patients with MSIMI had higher hemodynamic and digital vasoconstrictive responses (p<0.05 for both), but did not differ in epinephrine, endothelial or macrovascular responses. Only presence of ischemia during conventional stress (OR of 7.1, 95%CI of 4.2, 11.9), high hemodynamic response (OR for RPP response≥vs<ROC cutoff of 1.8, 95%CI of 1.1, 2.8), and high digital vasoconstriction (OR for PAT ratio<vs≥ROC cutoff of 2.1, 95%CI of 1.3, 3.3) were independent predictors of MSIMI.

CONCLUSION

Ischemia during conventional stress testing and hemodynamic and vasoconstrictive responses to mental stress can help predict subjects with CAD at greater risk of developing MSIMI.

Association Between High-Sensitivity Cardiac Troponin Levels and Myocardial Ischemia During Mental Stress and Conventional Stress

OBJECTIVES

This study sought to investigate whether patients with mental stress-induced myocardial ischemia will have high resting and post-mental stress high-sensitivity cardiac troponin I (hs-cTnI).

BACKGROUND

Hs-cTnI is a marker of myocardial necrosis, and its elevated levels are associated with adverse outcomes. Hs-cTnI levels may increase with exercise in patients with coronary artery disease. Mental stress-induced myocardial ischemia is also linked to adverse outcomes.

METHODS

In this study, 587 patients with stable coronary artery disease underwent technetium Tc 99m sestamibi-single-photon emission tomography myocardial perfusion imaging during mental stress testing using a public speaking task and during conventional (pharmacological/exercise) stress testing as a control condition. Ischemia was defined as new/worsening impairment in myocardial perfusion using a 17-segment model.

RESULTS

The median hs-cTnI resting level was 4.3 (interquartile range [IQR]: 2.9 to 7.3) pg/ml. Overall, 16% and 34.8% of patients developed myocardial ischemia during mental and conventional stress, respectively. Compared with those without ischemia, median resting hs-cTnI levels were higher in patients who developed ischemia either during mental stress (5.9 [IQR: 3.9 to 8.3] pg/ml vs. 4.1 [IQR: 2.7 to 7.0] pg/ml; p < 0.001) or during conventional stress (5.4 [IQR: 3.9 to 9.3] pg/ml vs. 3.9 [IQR: 2.5 to 6.5] pg/ml; p < 0.001). Patients with high hs-cTnI (cutoff of 4.6 pg/ml for men and 3.9 pg/ml for women) had greater odds of developing mental (odds ratio [OR]: 2.4; 95% confidence interval [CI]: 1.5 to 3.9; p < 0.001) and conventional (OR: 2.4; 95% CI: 1.7 to 3.4; p < 0.001) stress-induced ischemia. Although there was a significant increase in 45-min post-treadmill exercise hs-cTnI levels in those who developed ischemia, there was no significant increase after mental or pharmacological stress test.

CONCLUSIONS

In patients with coronary artery disease, myocardial ischemia during either mental stress or conventional stress is associated with higher resting levels of hs-cTnI. This suggests that hs-cTnI elevation is an indicator of chronic ischemic burden experienced during everyday life. Whether elevated hs-cTnI levels are an indicator of adverse prognosis beyond inducible ischemia or whether it is amenable to intervention requires further investigation.