Acute and chronic psychological stress in coronary disease

The Impact of War-Related Stress on Coronary Artery Disease Severity in War Survivors: A SYNTAX Study

Background: Due to the strong relationship between stress and heart disease, particularly acute myocardial infarction (MI), this study investigated the complexity of coronary artery disease (CAD) among Syrian refugee patients referred to Jordan University Hospital and its relation to war-related stressors. Methods: This is a retrospective study that utilized the SYNTAX I score in order to evaluate all Syrian refugees that underwent coronary artery catheterization at Jordan University Hospital during the period between May of 2014 and December of 2017. Results: There was a significant association between war-related stressors and high SYNTAX score (SX score), thus indicating a higher complexity of CAD in Syrian war survivors with higher stress scores. The strongest war-related correlation was observed with crossing green-lines, in which Syrian refugee patients who had crossed such lines had significantly higher SYNTAX scores. Regression analysis demonstrated that war stressors were positive predictors of increased SYNTAX scores even when adjusted for conventional CAD risk factors. Surprisingly, none of the CAD risk factors were significantly associated with SYNTAX score. Conclusion: Our findings suggest that exposure to multiple war-related stressors may increase the complexity and severity of CAD in Syrian war survivors. Thus, special attention, efforts, and resources should be allocated to screen for such vulnerable patients in order to provide them with the appropriate healthcare.

Association of napping with incident cardiovascular events in a prospective cohort study

Objective

There is controversy regarding the effect of napping on cardiovascular disease (CVD), with most studies failing to consider napping frequency. We aimed to assess the relationship of napping frequency and average nap duration with fatal and non-fatal CVD events.

Methods

3462 subjects of a Swiss population based cohort with no previous history of CVD reported their nap frequency and daily nap duration over a week, and were followed over 5.3 years. Fatal and non-fatal CVD events were adjudicated. Cox regressions were performed to obtain HRs adjusted for major cardiovascular risk factors and excessive daytime sleepiness or obstructive sleep apnoea.

Results

155 fatal and non-fatal events occurred. We observed a significantly lower risk for subjects napping 1–2 times weekly for developing a CVD event (HR 0.52, 95% CI 0.28 to 0.95) compared with non-napping subjects, in unadjusted as well as adjusted models. The increased HR (1.67, 95% CI 1.10 to 2.55) for subjects napping 6–7 times weekly disappeared in adjusted models (HR 0.89, 95% CI 0.58 to 1.38). Neither obstructive sleep apnoea nor excessive daytime sleepiness modified this lower risk. No association was found between nap duration and CVD events.

Conclusion

Subjects who nap once or twice per week have a lower risk of incident CVD events, while no association was found for more frequent napping or napping duration. Nap frequency may help explain the discrepant findings regarding the association between napping and CVD events.

Longer Sleep Duration and Midday Napping Are Associated with a Higher Risk of CHD Incidence in Middle-Aged and Older Chinese: the Dongfeng-Tongji Cohort Study

STUDY OBJECTIVES

To analyze the independent and combined relations of sleep duration and midday napping with coronary heart diseases (CHD) incidence along with the underlying changes of cardiovascular disease (CVD) risk factors among Chinese adults.

METHODS

We included 19,370 individuals aged 62.8 years at baseline from September 2008 to June 2010, and they were followed until October 2013. Cox proportional hazards models and general linear models were used for multivariate longitudinal analyses.

RESULTS

Compared with sleeping 7- < 8 h/night, the hazard ratio (HR) of CHD incidence was 1.33 (95% CI = 1.10 to 1.62) for sleeping ≥ 10 h/night. The association was particularly evident among individuals who were normal weight and without diabetes. Similarly, the HR of incident CHD was 1.25 (95% CI = 1.05 to 1.49) for midday napping > 90 min compared with 1-30 min. When sleep duration and midday napping were combined, individuals having sleep duration ≥ 10 h and midday napping > 90 min were at a greater risk of CHD than those with sleeping 7- < 8 h and napping 1-30 min: the HR was 1.67 (95% CI = 1.04 to 2.66; P for trend = 0.017). In addition, longer sleep duration ≥ 10 h was significantly associated with increases in triglycerides and waist circumference, and a reduction in HDL-cholesterol; while longer midday napping > 90 min was related to increased waist circumference.

CONCLUSIONS

Both longer sleep duration and midday napping were independently and jointly associated with a higher risk of CHD incidence, and altered lipid profile and waist circumference may partially explain the relationships.

Correlation between LIFG and autonomic activation during stressful tasks: a functional near-infrared spectroscopy (fNIRS) study

It remains unclear whether language tasks in one's first (L1) or second (L2) language can cause stress responses and whether frontal, autonomic and behavioral responses to stressful tasks are correlated. In this study, we studied 22 Chinese subjects whose L2 was English and measured the cerebral blood oxygenation in their frontal lobe by using functional near-infrared spectroscopy (fNIRS) as participants engaged in a mental arithmetic task (MAT) and verbal fluency tasks (VFTs) in L1 (Chinese) and L2 (English). To examine the activated cortical areas, we estimated the channel location based on Montreal Neurological Institute (MNI) standard brain space by using a probabilistic estimation method. We evaluated heart rate (HR) changes to analyze autonomic nervous system (ANS) functioning. We found that the MAT and VFTs induced greater increases in HR than did the control (Ctrl) task. Furthermore, subjects developed greater increases in HR in the MAT and VFTL2 than they did in the VFTL1. Compared with the Ctrl task, the MAT and both VFTL1 and VFTL2 produced robust and widespread bilateral activation of the frontal cortex. Interestingly, partial correlation analysis indicated that the activity in the left inferior frontal gyrus (LIFG) [Brodmann's area (BA) 47] was consistently correlated with the increases in HR across the three tasks (MAT, VFTL2, and VFTL1), after controlling for the performance data. The present results suggested that a VFT in L2 may be more stressful than in L1. The LIFG may affect the activation of the sympathetic system induced by stressful tasks, including MATs and VFTs.

Role of central oxytocin in stress-induced cardioprotection in ischemic-reperfused heart model

BACKGROUND AND PURPOSE

There is growing evidence that stress contributes to cardiovascular disease and triggers the release of oxytocin. Moreover previous studies confirmed oxytocin mimics the protection associated with ischemic preconditioning. The present study was aimed to assess the possible cardioprotective effects of the centrally released oxytocin in response to stress and intracerebroventricular (i.c.v.) administration of exogenous oxytocin in ischemic-reperfused isolated rat heart.

METHODS AND SUBJECTS

Rats were divided in two main groups and all of them were subjected to i.c.v. infusion of vehicle or drugs: unstressed rats [control: vehicle, oxytocin (OT; 100 ng/5 μl), atosiban (ATO; 4.3 μg/5 μl) as oxytocin antagonist, ATO+OT] and stressed rats [St: stress, OT+St, ATO+St]. After anesthesia, hearts were isolated and subjected to 30 min regional ischemia and 60 min reperfusion (IR). Acute stress protocol included swimming for 10 min before anesthesia. Myocardial function, infarct size, coronary flow, ventricular arrhythmia, and biochemical parameters such as creatine kinase and lactate dehydrogenase were measured. Ischemia-induced ventricular arrhythmias were counted during the occlusion period.

RESULTS

The plasma levels of oxytocin and corticosterone were significantly elevated by stress. Unexpectedly hearts of stressed rats showed a marked depression of IR injury compared to control group. I.c.v. infusion of oxytocin mimicked the cardioprotective effects of stress, yet did not elevate plasma oxytocin level. The protective effects of both stress and i.c.v. oxytocin were blocked by i.c.v. oxytocin antagonist.

CONCLUSIONS

These findings suggest that i.c.v. infusion of exogenous oxytocin and centrally released endogenous oxytocin in response to stress could play a role in induction of a preconditioning effect in ischemic-reperfused rat heart via brain receptors.

The association between stress and physical health in parents caring for children with intellectual disabilities is moderated by children’s challenging behaviours

The present study examined the moderating role of social support and challenging behaviour on the stress–physical health relationship in parents caring for children with intellectual disabilities. Parents of children with intellectual disabilities ( n = 70) reported more physical health problems compared to control parents ( n = 45) and were more likely to visit their general practitioner. Furthermore, challenging behaviours, but not social support, moderated this association: parents of children with intellectual disabilities reported poorer physical health when both challenging behaviours and stress were perceived to be high. These findings suggest that interventions need to be directed towards ameliorating the impact of challenging behaviours.

Taking the Perspective that a Depressive State Reflects Inflammation: Implications for the Use of Antidepressants

This paper reviews both the evidence that supports the characterization of depression as an inflammatory disorder and the different biochemical mechanisms that have been postulated for the connection between inflammation and depression. This association offers credible explanation for the short term efficacy of antidepressants, which have short term anti-inflammatory effects. Evidence for those anti-inflammatory effects is discussed. Evidence of the contrary long-term effects of antidepressants, which increase rather than decrease inflammation, is also reviewed. It is argued that this increase in inflammation would predict an increase in chronicity among depressed patients that have been treated with antidepressants drugs, which has been noted in the literature. A brief discussion of alternatives for decreasing inflammation, some of which have demonstrated efficacy in ameliorating depression, is presented.

Stress-induced susceptibility to sudden cardiac death in mice with altered serotonin homeostasis

In humans, chronic stressors have long been linked to cardiac morbidity. Altered serotonergic neurotransmission may represent a crucial pathophysiological mechanism mediating stress-induced cardiac disturbances. Here, we evaluated the physiological role of serotonin (5-HT) 1A receptors in the autonomic regulation of cardiac function under acute and chronic stress conditions, using 5-HT_1A receptor knockout mice (KOs). When exposed to acute stressors, KO mice displayed a higher tachycardic stress response and a larger reduction of vagal modulation of heart rate than wild type counterparts (WTs). During a protocol of chronic psychosocial stress, 6 out of 22 (27%) KOs died from cardiac arrest. Close to death, they displayed a severe bradycardia, a lengthening of cardiac interval (P wave, PQ and QRS) duration, a notched QRS complex and a profound hypothermia. In the same period, the remaining knockouts exhibited higher values of heart rate than WTs during both light and dark phases of the diurnal rhythm. At sacrifice, KO mice showed a larger expression of cardiac muscarinic receptors (M2), whereas they did not differ for gross cardiac anatomy and the amount of myocardial fibrosis compared to WTs. This study demonstrates that chronic genetic loss of 5-HT_1A receptors is detrimental for cardiovascular health, by intensifying acute, stress-induced heart rate rises and increasing the susceptibility to sudden cardiac death in mice undergoing chronic stress.

The effect of acute stress exposure on ischemia and reperfusion injury in rat heart: role of oxytocin

Previous studies showed the protective effects of oxytocin (OT) on myocardial injury in ischemic and reperfused rat heart. Moreover, exposure to various stressors not only evokes sudden cardiovascular effects but also triggers the release of OT in the rat. The present study was aimed to evaluate the possible cardioprotective effects of endogenous OT released in response to stress (St), and effects of administration of exogenous OT on the ischemic-reperfused isolated heart of rats previously exposed to St. Wistar rats were divided into six groups: ischemia/reperfusion (IR); St: rats exposed to swim St for 10 min before anesthesia; St+atosiban (ATO): an OT receptor antagonist, was administered (1.5 mg/kg i.p.) prior to St; St+OT: OT was administered (0.03 mg/kg i.p.) prior to St; OT: OT was administrated prior to anesthesia; ATO was given prior to anesthesia. Isolated hearts were perfused with Krebs buffer solution by the Langendorff method and subjected to 30 min of regional ischemia followed by 60 min of reperfusion. The infarct size (IS) and creatine kinase MB isoenzyme (CK-MB) and lactate dehydrogenase (LDH) in coronary effluent were measured. Hemodynamic parameters were recorded throughout the experiment. The plasma concentrations of OT and corticosterone were significantly increased by St. Unexpectedly St decreased IR injury compared with the IR alone group. OT administration significantly inhibited myocardial injury, and administration of ATO with St abolished recovery of the rate pressure product, and increased IS and levels of CK-MB and LDH. These findings indicate that activation of cardiac OT receptors by OT released in response to St may participate in cardioprotection and inhibition of myocardial IR injury.

Do Stress Trajectories Predict Mortality in Older Men? Longitudinal Findings from the VA Normative Aging Study

We examined long-term patterns of stressful life events (SLE) and their impact on mortality contrasting two theoretical models: allostatic load (linear relationship) and hormesis (inverted U relationship) in 1443 NAS men (aged 41-87 in 1985; M = 60.30, SD = 7.3) with at least two reports of SLEs over 18 years (total observations = 7,634). Using a zero-inflated Poisson growth mixture model, we identified four patterns of SLE trajectories, three showing linear decreases over time with low, medium, and high intercepts, respectively, and one an inverted U, peaking at age 70. Repeating the analysis omitting two health-related SLEs yielded only the first three linear patterns. Compared to the low-stress group, both the moderate and the high-stress groups showed excess mortality, controlling for demographics and health behavior habits, HRs = 1.42 and 1.37, ps <.01 and <.05. The relationship between stress trajectories and mortality was complex and not easily explained by either theoretical model.

The association between chronic stress type and C-reactive protein in the multi-ethnic study of atherosclerosis: does gender make a difference?

The objective of this study is to examine how chronic stress in major life domains [relationship, work, sympathetic-caregiving, financial] relates to CVD risk, operationalized using the inflammatory marker C-Reactive Protein (CRP), and whether gender differences exist. Participants were 6,583 individuals aged 45-84 years, recruited as part of the Multi-Ethnic Study of Atherosclerosis. Demographic and behavioral factors, health history, and chronic stress were self-reported. CRP was obtained through venous blood draw. In aggregate, gender by chronic stress interaction effects accounted for a significant, albeit small, amount of variance in CRP (P < .01). The sympathetic-caregiving stress by gender interaction was significant (P < .01); the work stress by gender effect approached significance (P = .05). Women with sympathetic-caregiving stress had higher CRP than those without, whereas no difference in CRP by stress group was observed for men. Findings underscore the importance of considering gender as an effect modifier in analyses of stress-CVD risk relationships.

Stock volatility as a risk factor for coronary heart disease death

AIMS

The volatility of financial markets may cause substantial emotional and physical stress among investors. We hypothesize that this may have adverse effects on cardiovascular health. The Chinese stock markets were extremely volatile between 2006 and 2008. We, therefore, examined the relationship between daily change of the Shanghai Stock Exchange (SSE) Composite Index (referred as the Index) and coronary heart disease (CHD) deaths from 1 January 2006 to 31 December 2008 in Shanghai, the financial capital of China.

METHODS AND RESULTS

Daily death and stock performance data were collected from the Shanghai Center for Disease Control and Prevention and SSE, respectively. Data were analysed with over-dispersed generalized linear Poisson models, controlling for long-term and seasonal trends of CHD mortality, day of the week, Index closing value, weather conditions, and air pollution levels. We observed a U-shaped relationship between the Index change and CHD deaths: both rising and falling of the Index were associated with more deaths and the fewest deaths coincided with little or no change of the index. We also examined the absolute daily change of the Index in relation to CHD deaths: in a 1-day lag model, each 100-point change of the Index corresponded to 5.17% (95% confidence interval: 1.71, 8.63%) increase in CHD deaths. Further analysis showed that the association was stronger for out-of-hospital CHD death than for in-hospital death.

CONCLUSION

We found that CHD deaths fluctuated with daily stock changes in Shanghai, suggesting that stock volatility may adversely affect cardiovascular health.

Connecting chronic and recurrent stress to vascular dysfunction: no relaxed role for the renin-angiotensin system

The renin-angiotensin system (RAS) is classically considered to be a protective system for volume balance and is activated during states of volume depletion. Interestingly, one of the major pathways activating the system is the sympathetic nervous system, also the primary mediator of the acute stress response. When one further examines the cells mediating the immune site of the response, which is primarily an inflammatory response leading to defense at a locally injured area, these cells all express the ANG II type 1 receptor (AGTR1). Scattered throughout the literature are reports indicating that acute and chronic stress can activate renin and increase plasma levels of components of the RAS. Moreover, there are reports describing that ANG II can modulate the distribution and function of immune cells. Since the inflammatory response is also implicated to be central in the initiation and progression of vascular damage, we propose in this review that recurrent acute stress and chronic stress can induce a state with inflammation, due to ANG II-mediated activation of inflammatory cells, specifically monocytes and lymphocytes. Such a proposal would explain a lot of the observations regarding RAS components in inflammatory cells. Despite its attractiveness, substantial research in this area would be required to substantiate this hypothesis.

Effect of Hurricane Katrina on the incidence of acute coronary syndrome at a primary angioplasty center in New Orleans

BACKGROUND

In August 2005, New Orleans was hit by Hurricane Katrina, the costliest natural disaster in US history. Previous studies have shown an increase in acute myocardial infarction (AMI) in the immediate hours to weeks after natural disasters. The goals of our study were to detect any long-term increase in the incidence of AMI after Katrina and to investigate any pertinent contributing factors.

METHODS

This was a single-center retrospective cohort observational study. Patients admitted with AMI to Tulane Health Sciences Center hospital in the 2 years before Katrina and in the 2 years after the hospital reopened (5 months after Katrina) were identified from hospital records. The 2 groups (pre- and post-Katrina) were compared for prespecified demographic and clinical data.

RESULTS

In the post-Katrina group, there were 246 admissions for AMI, out of a total census of 11,282 patients (2.18%), as compared with 150 AMI admissions out of a total of 21,229 patients (0.71%) in the pre-Katrina group (P < 0.0001). The post-Katrina group had a significantly higher prevalence of unemployment (P = 0.0003), lack of medical insurance (P < 0.0001), medication noncompliance (P = 0.0001), smoking (P = 0.001), substance abuse (P = 0.03), first-time hospitalization (P < 0.001), local residents rather than visitors affected (P < 0.0001), and people living in temporary housing (P = 0.003).

DISCUSSION

The role of chronic stress in the pathogenesis of AMI is poorly understood, especially in the aftermath of natural disasters. Our data suggest that Katrina was associated with prolonged loss of employment and insurance, decreased access to preventive health services, and an increased incidence of AMI. In addition, it appears that chronic stress after a natural disaster can be associated with tobacco abuse and medication and therapeutic noncompliance.

CONCLUSIONS

We found a 3-fold increased incidence of AMI more than 2 years after Hurricane Katrina. Even allowing for the loss of some local hospitals after the disaster, this represents a significant change in overall health of the study population and supports the need for further study into the health effects of chronic stress.

Variables influencing heart rate

In both physiologic and pathological conditions, instantaneous heart rate value is the result of a rather complex interplay. It constantly varies under the influence of a number of factors: nonmodifiable and modifiable ones. Pharmacologic blockade with beta-adrenergic antagonists and/or with parasympathetic antagonists such as atropine have permitted the identification of the mechanisms of autonomic nervous regulation of heart rate in a variety of physiologic and pathological conditions. The analysis of heart rate and blood pressure variability has yielded additional information on the autonomic control of the circulation, which has proven to have diagnostic and prognostic implications in a number of clinically relevant conditions such as hypertension, acute myocardial infarction, heart failure, and predisposition to sudden cardiac death. This article will summarize, based on available epidemiologic and clinical studies, the key variables influencing heart rate and heart rate variability in view of the known association between heart rate and cardiovascular disease.

The effect of a six-week program of yoga and meditation on brachial artery reactivity: do psychosocial interventions affect vascular tone?

BACKGROUND

Chronic stress is estimated to increase the risk of cardiovascular (CV) events two-fold. Although stress reduction has been linked to a reduction in CV events, little is known regarding its exact mechanism of benefit.

HYPOTHESIS

Yoga and meditation will improve parameters of endothelial function.

METHODS

We examined the effects of yoga and meditation on hemodynamic and laboratory parameters as well as on endothelial function in a 6-week pilot study. Systolic and diastolic blood pressures, heart rate, body mass index (BMI), fasting glucose, lipids, hs C-reactive protein (CRP), and endothelial function (as assessed by brachial artery reactivity) were all studied at baseline and after 6 weeks of yoga practice.

RESULTS

A course in yoga and meditation was given to the subjects for 1.5 h three times weekly for 6 weeks and subjects were instructed to continue their efforts at home. This prospective cohort study included 33 subjects (mean age 55 +/- 11 years) both with (30%) and without (70%) established coronary artery disease (CAD). There were significant reductions in blood pressure, heart rate, and BMI in the total cohort with yoga. None of the laboratory parameters changed significantly with yoga. For the total cohort there was no significant improvement in endothelial-dependent vasodilatation with yoga training and meditation compared with baseline (16.7% relative improvement from 7.2-8.4%; p = 0.3). In the group with CAD, endothelial-dependent vasodilatation improved 69% with yoga training (6.38-10.78%; p = 0.09).

CONCLUSION

Yoga and meditation appear to improve endothelial function in subjects with CAD.

Associations of plasma 8-isoprostane levels with the presence and extent of coronary stenosis in patients with coronary artery disease

Oxidative stress may play a role in the development of atherosclerosis. The purpose of the present study was to explore the relationship between 8-isoprostaglandin F(2alpha) (8-iso-PGF(2alpha)) levels and the presence of coronary artery disease (CAD) and to also clarify whether 8-iso-PGF(2alpha) might add independently to measures of CAD extent. The study group consisted of 241 consecutive patients who were undergoing coronary angiography for suspected CAD. 8-iso-PGF(2alpha) levels were recorded for all participants. The analysis revealed a significant difference in 8-iso-PGF(2alpha) levels in patients with and without hypertension (P<0.001), in patients with diabetes relative to nondiabetic patients (P<0.05), and in males respect to females (P<0.001). A significant positive correlation was found between age and 8-iso-PGF(2alpha) levels (P<0.001). 8-iso-PGF(2alpha) levels correlated with the number of cardiovascular risk factors (P<0.001). 8-iso-PGF(2alpha) levels were higher in the CAD(+) respect to the CAD(-) groups (337.7+/-80.2 and 263.8+/-74.2 pg/ml and P<0.001). A stepwise elevation in the 8-iso-PGF(2alpha) levels was found depending on the number of affected vessels (P<0.001). The 8-iso-PGF(2alpha) levels showed a significant positive correlation with the numbers of >50 and >25% stenotic segments (P<0.001) and the extent score of coronary stenosis (P<0.001). The multivariate logistic regression analysis indicated 8-iso-PGF(2alpha) as an independent factor associated with CAD (odds ratio, 2.47 and P=0.001). The results suggested that 8-iso-PGF(2alpha) is associated with the presence of CAD in patients undergoing coronary angiography and is also related to the extent of coronary stenosis in Chinese population.