Anxiety, Mental Stress, and Sudden Cardiac Arrest: Epidemiology, Possible Mechanisms and Future Research

Baseline and 10-year change in the number of ideal cardiovascular health metrics and sudden cardiac death in the community

AIMS

Adherence to an ideal cardiovascular health (CVH) might contribute to lower the burden of sudden cardiac death (SCD) in the community. We aimed to examine the association between the number of ideal CVH metrics at baseline and of its change over 10 years with the risk of SCD.

METHODS AND RESULTS

The Copenhagen City Heart Study is a community-based prospective cohort study. The number of ideal CVH metrics (range 0-6; non-smoking and ideal level of body mass index, physical activity, untreated glucose, untreated systolic blood pressure, and untreated total cholesterol levels) at baseline in 1991-94 and its 10-year change thereof between 1981-83 and 1991-94 were evaluated. Definite SCD was defined as a death occurring within 1 h (eye-witnessed case) or within 24 h (non-eye-witnessed) of symptoms onset, with the presence of confirmed ventricular tachycardia and the exclusion of non-cardiac cause at autopsy. Fine and Gray sub-distribution HRs (sHRs) were calculated to account for competing risk. The study population includes 8837 participants (57% women; mean age 57 years, ±15 years) in 1991-94. After a median follow-up of 22.6 years from 1 January 1993 up to 31 December 2016, 56 definite SCD occurred. The risk of definite SCD decreased gradually with the number of ideal metrics in 1991-94 [sHR = 0.58; 95% confidence interval (CI): 0.44-0.75 per additional ideal metric] and with the change (i.e. improvement) in the number of ideal metrics between 1981-83 and 1991-94 (sHR = 0.68; 0.50-0.93 per change in the number of ideal metrics). Effect size was lower for coronary death, all-cause mortality, and coronary heart disease events.

CONCLUSION

Adherence to a higher number of ideal cardiovascular health was related to a substantial lower risk of definite SCD.

The role of torso stiffness and prediction in the biomechanics of anxiety: a narrative review

Although anxiety is a common psychological condition, its symptoms are related to a cardiopulmonary strain which can cause palpitation, dyspnea, dizziness, and syncope. Severe anxiety can be disabling and lead to cardiac events such as those seen in Takotsubo cardiomyopathy. Since torso stiffness is a stress response to unpredictable situations or unexpected outcomes, studying the biomechanics behind it may provide a better understanding of the pathophysiology of anxiety on circulation, especially on venous impedance. Any degree of torso stiffness related to anxiety would limit venous return, which in turn drops cardiac output because the heart can pump only what it receives. Various methods and habits used to relieve stress seem to reduce torso stiffness. Humans are large obligatory bipedal upright primates and thus need to use the torso carefully for smooth upright activities with an accurate prediction. The upright nature of human activity itself seems to contribute to anxiety due to the needed torso stiffness using the very unstable spine. Proper planning of actions with an accurate prediction of outcomes of self and non-self would be critical to achieving motor control and ventilation in bipedal activities. Many conditions linked to prediction errors are likely to cause various degrees of torso stiffness due to incomplete learning and unsatisfactory execution of actions, which will ultimately contribute to anxiety. Modifying environmental factors to improve predictability seems to be an important step in treating anxiety. The benefit of playful aerobic activity and proper breathing on anxiety may be from the modulation of torso stiffness and enhancement of central circulation resulting in prevention of the negative effect on the cardiopulmonary system.

Association of Evening Shifts, Night Shifts, and Consistent Overtime Exceeding 10 Hours per Day with Sudden Cardiac Arrest: A Case-Control Study

Background: We investigated the relationship between employment status, work patterns, and sudden cardiac arrest (SCA). Methods: This was a case-control study from September 2017 through December 2022 involving 17 emergency departments and 9 public health centers. The cases included patients aged 20-79 years with SCA, excluding those with traumatic arrest, terminal illness, pregnancy, unreliable information, or a "Do Not Resuscitate" order. Controls were selected from various health screening centers in Korea. All participants completed structured questionnaires. Propensity score matching was used to ensure comparability by age, sex, and socioeconomic status. Results: Of the 1536 patients enrolled, 116 from the case group were excluded due to missing employment data, leaving 1420 cases and 2304 controls for analysis. Employment was reported by 47.5% of cases and 59.4% of controls. There was no significant difference in the proportion of sole proprietors (20.6% vs. 22.5%, p = 0.39). The case group had a higher proportion of employers (13.2% vs. 6.5%, p < 0.001) and fewer employees (63.3% vs. 69.1%, p = 0.02). Professional roles were more common among controls (23.6% vs. 31.6%, p < 0.001), while labor-intensive jobs were more frequent in cases (27.7% vs. 17.8%, p < 0.001). The case group had more evening and night shifts (odds ratio [OR]: 1.04, 95% confidence interval [CI]: 1.01-1.06; OR: 1.05, 95% CI: 1.01-1.09) and longer workdays (OR: 1.06, 95% CI: 1.03-1.08). Conclusions: SCA patients were more likely to work evening and night shifts and have longer workdays, often exceeding 10 h.

Multitargeting in cardioprotection: An example of biaromatic compounds

A multitarget drug design approach is actively developing in modern medicinal chemistry and pharmacology, especially with regard to multifactorial diseases such as cardiovascular diseases, cancer, and neurodegenerative diseases. A detailed study of many well-known drugs developed within the single-target approach also often reveals additional mechanisms of their real pharmacological action. One of the multitarget drug design approaches can be the identification of the basic pharmacophore models corresponding to a wide range of the required target ligands. Among such models in the group of cardioprotectors is the linked biaromatic system. This review develops the concept of a "basic pharmacophore" using the biaromatic pharmacophore of cardioprotectors as an example. It presents an analysis of possible biological targets for compounds corresponding to the biaromatic pharmacophore and an analysis of the spectrum of biological targets for the five most known and most studied cardioprotective drugs corresponding to this model, and their involvement in the biological effects of these drugs.

Neuropsychological outcome after cardiac arrest: results from a sub-study of the targeted hypothermia versus targeted normothermia after out-of-hospital cardiac arrest (TTM2) trial

BACKGROUND

Cognitive impairment is common following out-of-hospital cardiac arrest (OHCA), but the nature of the impairment is poorly understood. Our objective was to describe cognitive impairment in OHCA survivors, with the hypothesis that OHCA survivors would perform significantly worse on neuropsychological tests of cognition than controls with acute myocardial infarction (MI). Another aim was to investigate the relationship between cognitive performance and the associated factors of emotional problems, fatigue, insomnia, and cardiovascular risk factors following OHCA.

METHODS

This was a prospective case-control sub-study of The Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial. Eight of 61 TTM2-sites in Sweden, Denmark, and the United Kingdom included adults with OHCA of presumed cardiac or unknown cause. A matched non-arrest control group with acute MI was recruited. At approximately 7 months post-event, we administered an extensive neuropsychological test battery and questionnaires on anxiety, depression, fatigue, and insomnia, and collected information on the cardiovascular risk factors hypertension and diabetes.

RESULTS

Of 184 eligible OHCA survivors, 108 were included, with 92 MI controls enrolled. Amongst OHCA survivors, 29% performed z-score ≤ - 1 (at least borderline-mild impairment) in ≥ 2 cognitive domains, 14% performed z-score ≤ - 2 (major impairment) in ≥ 1 cognitive domain while 54% performed without impairment in any domain. Impairment was most pronounced in episodic memory, executive functions, and processing speed. OHCA survivors performed significantly worse than MI controls in episodic memory (mean difference, MD = - 0.37, 95% confidence intervals [- 0.61, - 0.12]), verbal (MD = - 0.34 [- 0.62, - 0.07]), and visual/constructive functions (MD = - 0.26 [- 0.47, - 0.04]) on linear regressions adjusted for educational attainment and sex. When additionally adjusting for anxiety, depression, fatigue, insomnia, hypertension, and diabetes, executive functions (MD = - 0.44 [- 0.82, - 0.06]) were also worse following OHCA. Diabetes, symptoms of anxiety, depression, and fatigue were significantly associated with worse cognitive performance.

CONCLUSIONS

In our study population, cognitive impairment was generally mild following OHCA. OHCA survivors performed worse than MI controls in 3 of 6 domains. These results support current guidelines that a post-OHCA follow-up service should screen for cognitive impairment, emotional problems, and fatigue.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03543371. Registered 1 June 2018.

Minor perturbations of thyroid homeostasis and major cardiovascular endpoints—Physiological mechanisms and clinical evidence

It is well established that thyroid dysfunction is linked to an increased risk of cardiovascular morbidity and mortality. The pleiotropic action of thyroid hormones strongly impacts the cardiovascular system and affects both the generation of the normal heart rhythm and arrhythmia. A meta-analysis of published evidence suggests a positive association of FT4 concentration with major adverse cardiovascular end points (MACE), but this association only partially extends to TSH. The risk for cardiovascular death is increased in both subclinical hypothyroidism and subclinical thyrotoxicosis. Several published studies found associations of TSH and FT4 concentrations, respectively, with major cardiovascular endpoints. Both reduced and elevated TSH concentrations predict the cardiovascular risk, and this association extends to TSH gradients within the reference range. Likewise, increased FT4 concentrations, but high-normal FT4 within its reference range as well, herald a poor outcome. These observations translate to a monotonic and sensitive effect of FT4 and a U-shaped relationship between TSH and cardiovascular risk. Up to now, the pathophysiological mechanism of this complex pattern of association is poorly understood. Integrating the available evidence suggests a dual etiology of elevated FT4 concentration, comprising both ensuing primary hypothyroidism and a raised set point of thyroid function, e. g. in the context of psychiatric disease, chronic stress and type 2 allostatic load. Addressing the association between thyroid homeostasis and cardiovascular diseases from a systems perspective could pave the way to new directions of research and a more personalized approach to the treatment of patients with cardiovascular risk.

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.

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.