Is there a high-risk subtype of depression in patients with coronary heart disease?

Depressive Symptom Subgroups and Their Association with Prevalent and Incident Cardiovascular Risk Factors in the Coronary Artery Risk Development in Young Adults (CARDIA) Study

BACKGROUND

We sought to identify depressive symptom subgroups in a community sample of young adults, investigate their stability over time, and determine their association with prevalent and incident cardiovascular disease (CVD) risk factors.

METHOD

Participants were 3377 adults from the Coronary Artery Risk Development in Young Adults study. Using latent class and latent transition analysis, we derived subgroups based on items of the 20-item version of the Center for Epidemiologic Studies Depression Scale in 1990, and examined patterns of change over a 10-year period (1990-2000). Cox regression models were used to examine associations between subgroup membership and prevalent (2000) and incident (2000 to 2016) obesity, hypertension, and diabetes.

RESULTS

Three baseline subgroups were identified and labeled: "No Symptoms" (63.5%), "Lack of Positive Affect" (PA, 25.6%), and "Depressed Mood" (10.9%). At 10-year follow-up, individuals in "No Symptoms" subgroup had the highest probability (0.84) of being classified within the same subgroup. Participants classified as "Lack of PA" were likely (0.46) to remain in the same subgroup or be classified as "No Symptoms." Participants in the "Depressed Mood" were most likely to transition to the "Lack of PA" subgroup (0.38). Overall, 30.5% of participants transitioned between subgroups, with 11.4% classified as "Worsening" and 19.1% as "Improving." Relative to the "No Symptoms Stable," other subgroups ("Depressed Stable," "Worsening," and "Improving") were associated with prevalent obesity and hypertension.

CONCLUSION

We identified distinct depressive symptom subgroups that are variably stable over time, and their change patterns were differentially associated with CVD risk factor prevalence.

Serum Metabolomic Analysis of Coronary Heart Disease Patients with Stable Angina Pectoris Subtyped by Traditional Chinese Medicine Diagnostics Reveals Biomarkers Relevant to Personalized Treatments

To improve the treatment of patients with coronary heart disease (CHD), personalized treatments based on potential biomarkers could make a difference. To investigate if such potential biomarkers could be found for CHD inhomogeneous, we combined traditional Chinese medicine based diagnosis with untargeted and targeted metabolomics analyses. Shi and Xu patient subtype groups of CHD with angina pectoris were identified. Different metabolites including lipids, fatty acids and amino acids were further analyzed with targeted metabolomics and mapped to disease-related pathways. The long-chain unsaturated lipids ceramides metabolism, bile acid metabolism were differentially affected in the Xu subtype groups. While, Shi-subtype patients seemed to show inflammation, anomalous levels of bioactive phospholipids and antioxidant molecules. Furthermore, variations in the endothelial damage response and energy metabolism found based on ELISA analysis are the key divergence points between different CHD subtypes. The results showed Xu subtype patients might benefit from long-chain unsaturated lipids ceramides as therapeutic targets. Shi subtype patients might benefit more from levels of polyunsaturated fatty acid consumption and treatments that help in restoring energy balance. Metabolic differences can be essential for treatment protocols. Thus, patient group specific differences can serve as important information to refine current treatment approaches in a personalized manner.

Time-dependent cognitive and somatic symptoms of depression as predictors of new cardiac-related events in at-risk patients: the UPBEAT-UK cohort

BACKGROUND

Evidence suggests that somatic rather than cognitive depressive symptoms are risk factors for recurrent cardiac events in at-risk patients. However, this has never been explored using a time-dependent approach in a narrow time-frame, allowing a cardiac event-free time-window.

METHODS

The analysis was performed on 595 participants [70.6% male, median age 72 (27-98)] drawn from the UPBEAT-UK heart disease patient cohort with 6-monthly follow-ups over 3 years. Depressive symptomatology was measured using the Patient Health Questionnaire-9 (PHQ-9) (four somatic, five cognitive items). New cardiac events (NCEs) including cardiac-related mortality were identified by expert examination of patient records. Analyses were performed using Cox proportional hazard models with delayed entry, with time-dependent depressive dimensions and covariates measured 12-18 months (median: 14.1, IQR: 3.5) prior to the event, with a 12-month cardiac event-free gap.

RESULTS

There were 95 NCEs during the follow-up [median time-to-event from baseline: 22.3 months (IQR: 13.4)]. Both the somatic (HR 1.12, 95% CI 1.05-1.20, p = 0.001) and cognitive dimensions (HR 1.11, 95% CI 1.03-1.18, p = 0.004) were time-dependent risk factors for an NCE in the multi-adjusted models. Specific symptoms (poor appetite/overeating for the somatic dimension, hopelessness and feeling like a failure for the cognitive dimension) were also significantly associated.

CONCLUSION

This is the first study of the association between depressive symptom dimensions and NCEs in at-risk patients using a time-to-event standardised approach. Both dimensions considered apart were independent predictors of an NCE, along with specific items, suggesting regular assessments and tailored interventions targeting specific depressive symptoms may help to prevent NCEs in at-risk populations.

Depressive symptoms, its sub-factors, and augmentation index: the modifying effects according to inflammatory markers

Background This study aimed to investigate the association between depression and the augmentation index (AIx), and to further investigate whether there is a difference in this association according to the patients' inflammatory status. Methods This study included 458 men and 815 women (mean age: 49.35 years), a community-dwelling and middle-aged Korean population. The Korean version of the Beck Depression Inventory-II (BDI-II) was used to assess depressive symptoms. Arterial stiffness was evaluated via an AIx normalized to 75 beats/min. We confirmed two factors from BDI-II after conducting a factor analysis. Multiple regression models were used after adjusting for socio-demographic factors, lifestyle factors, systolic blood pressure, diabetes history, and body mass index. We further stratified the data according to inflammatory biomarkers with cutoffs of the 75^th percentile. Results There was a significant positive association between the BDI-II score and arterial stiffness (ß= 0.09, p-value=0.037). In women, the somatic-affective factor showed a stronger positive association (ß= 0.20, p-value=0.018) with arterial stiffness than the cognitive factor (ß= 0.12, p-value=0.148). There was no significant association in men (ß= -0.01, p-value=0.943). In subgroup analyses, women showed significant positive associations between the somatic affective factor of depressive symptoms on and arterial stiffness according to both inflammatory markers (IL-6: ß= 0.17, p-value=0.039; hs-CRP: ß= 0.17, p-value=0.094) Limitations The design of the cross-sectional study limits causal interpretation. Conclusion Depression and its somatic-affective factor were positively associated with arterial stiffness in women. Inflammatory status may be involved in modifying the association between depressive symptoms, its sub-factors, and AIx.

The association between psychological distress and angina pectoris: A population-based study

BACKGROUND

Psychological distress is an undifferentiated combination of symptoms that may be related to the occurrence of angina pectoris (AP). However, few studies have investigated the relationship between psychological distress and AP, particularly in Asian populations. The purpose of this study was to examine the relationship between psychological distress and AP in Taiwanese adults.

METHODS

We adopted a cross-sectional design to explore the data of the 2005-2008 Nutrition and Health Survey in Taiwan. In total, 2080 subjects (aged ≥ 19 years) responded to questionnaire interviews and underwent physical examinations. Each of the five dimensions of psychological distress (sleep disturbance, anxiety, hostility, depression, and feelings of inferiority) were scored (from 0-20) according to the Five-Item Brief Symptom Rating Scale (BSRS-5). A score ≥ 6 points indicated psychological distress. AP was evaluated using a modified Rose questionnaire.

FINDINGS

In total, 102 subjects (3.6%) had AP, and 231 subjects (8.8%) had symptoms of psychological distress. After adjusting for the basic data, metabolism, and lifestyle covariates, the BSRS-5 total score was associated with AP (odds ratio [OR] = 1.2, 95% confidence interval [CI] = 1.13-1.26, p < 0.001). Subjects with psychological distress had a higher risk of AP (OR = 2.97, 95% CI = 1.76-4.99, p < 0.001).

CONCLUSIONS

The presence of AP is associated with psychological distress. Health care providers should therefore be aware of the impact of psychological distress on AP. Our study findings can serve as a reference for AP assessments. Large scale longitudinal studies are needed to confirm a causal relationship between psychological distress and AP.

Comparing the effects of depression, anxiety, and comorbidity on quality-of-life, adverse outcomes, and medical expenditure in Chinese patients with acute coronary syndrome

Background:

Depression and anxiety have been correlated with elevated risks for quality-of-life (QOL), adverse outcomes, and medical expenditure in patients with acute coronary syndrome (ACS). However, the relevant data are lacking for Chinese ACS populations, especially regarding different effects of major depression, anxiety, and comorbidity. The objective of this study was to evaluate the dynamic changes of depression and/or anxiety over 12 months and examine the effects of depression, anxiety, and comorbidity on QOL, adverse outcomes, and medical expenditure in Chinese patients with ACS.

Methods:

For this prospective longitudinal study, a total of 647 patients with ACS were recruited from North China between January 2013 and June 2015. Among them, 531 patients (82.1%) completed 12-month follow-ups. Logistic regression model was utilized for analyzing the association of baseline major depression, anxiety, and comorbidity with 12-month all-cause mortality, cardiovascular events, QOL, and health expenditure.

Results:

During a follow-up period of 12 months, 7.3% experienced non-fatal myocardial infarction (MI) and 35.8% cardiac re-hospitalization. Baseline comorbidity, rather than major depression/anxiety, strongly predicted poor 12-month QOL as measured by short-form health survey-12 (odds ratio [OR]: 1.77, 95% confidence interval [CI]: 1.22–2.52, P = 0.003). Regarding 12-month non-fatal MI and cardiac re-hospitalization, baseline anxiety (OR: 2.83, 95% CI: 1.33–5.89, P < 0.01; OR: 4.47, 95% CI: 1.50–13.00, P < 0.01), major depression (OR: 2.58, 95% CI: 1.02–6.15, P < 0.05; OR: 5.22, 95% CI: 1.42–17.57, P < 0.03), and comorbidity (OR: 6.33, 95% CI: 2.96–13.79, P < 0.0001, OR: 14.08, 95% CI: 4.99–41.66, P < 0.0001) were all independent predictors, and comorbidity had the highest predictive value. Number of re-hospitalization stay, admission frequency within 12 months and medical expenditure within 2 months were the highest in patients with ACS with comorbidity.

Conclusions:

Major depression and anxiety may predict 12-month non-fatal MI and cardiac re-hospitalization. However, comorbidity has the highest predictive value with greater medical expenditure and worse QOL in Chinese patients with ACS. And depression with comorbid anxiety may be a new target of mood status in patients with ACS.

Depression Levels Following Discharge Predict Quality of Life in Heart Disease Patients

Abstract Depression and stress have been related with poor Health Related Quality of Life (HRQoL) prognosis. However, it is not clear when these depressive symptoms should be measured. A sample of 177 Coronary Heart Disease patients were followed for 15 months aimed to compare the effect of depression and stress measure at time of hospitalization and three months later on the physical HRQoL trajectory. Linear growth models’ results showed that depression and stress after discharge are negatively correlated with the physical HRQoL and depressive symptoms negatively affect the prognosis of these patients.

Hopelessness and cognitive impairment are risk markers for mortality in systolic heart failure patients

OBJECTIVE

Depression exacerbates the burden of heart failure and independently predicts mortality. The aim of this study was to investigate which specific symptoms of depression predict all-cause mortality in systolic heart failure patients.

METHODS

Consecutive outpatients with heart failure and impaired left ventricular ejection fraction (LVEF), attending an Australian metropolitan heart function clinic between 2001 and 2011, were enrolled. The Cardiac Depression Scale (CDS) was completed as a component of usual care. Baseline clinical characteristics were drawn from hospital databases. The primary end-point was all-cause mortality, obtained from the Australian National Death Index.

RESULTS

A total of 324 patients (68.5% male) were included (mean age at enrolment = 66.8 ± 14.36 years), with a median follow-up time of 6.7 years (95% CI 5.97-7.39) and a mortality rate of 50% by the census date. Mean LVEF = 31.0 ± 11.31%, with 25% having NYHA functional class of III or IV. Factor analysis of the CDS extracted six symptom dimensions: Hopelessness, Cognitive Impairment, Anhedonia/Mood, Irritability, Worry, and Sleep Disturbance. Cox regression analyses identified Hopelessness (HR 1.024, 95% CI 1.004-1.045, p = .018) and Cognitive Impairment (HR 1.048, 95% CI 1.005-1.093, p = .028) as independent risk markers of all-cause mortality, following adjustment of known prognostic clinical factors.

CONCLUSION

Hopelessness and cognitive impairment are stronger risk markers for all-cause mortality than other symptoms of depression in systolic heart failure. These data will allow more specific risk assessment and potentially new targets for more effective treatment and management of depression in this population.

Assessing mood symptoms through heartbeat dynamics: An HRV study on cardiosurgical patients

BACKGROUND

Heart Rate Variability (HRV) is reduced both in depression and in coronary heart disease (CHD) suggesting common pathophysiological mechanisms for the two disorders. Within CHD, cardiac surgery patients (CSP) with postoperative depression are at greater risk of adverse cardiac events. Therefore, CSP would especially benefit from depression early diagnosis. Here we tested whether HRV-multi-feature analysis discriminates CSP with or without depression and provides an effective estimation of symptoms severity.

METHODS

Thirty-one patients admitted to cardiac rehabilitation after first-time cardiac surgery were recruited. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale (CES-D). HRV features in time, frequency, and nonlinear domains were extracted from 5-min-ECG recordings at rest and used as predictors of "least absolute shrinkage and selection" (LASSO) operator regression model to estimate patients' CES-D score and to predict depressive state.

RESULTS

The model significantly predicted the CES-D score in all subjects (the total explained variance of CES-D score was 89.93%). Also it discriminated depressed and non-depressed CSP with 86.75% accuracy. Seven of the ten most informative metrics belonged to non-linear-domain.

LIMITATIONS

A higher number of patients evaluated also with a structured clinical interview would help to generalize the present findings.

DISCUSSION

To our knowledge this is the first study using a multi-feature approach to evaluate depression in CSP. The high informative power of HRV-nonlinear metrics suggests their possible pathophysiological role both in depression and in CHD. The high-accuracy of the algorithm at single-subject level opens to its translational use as screening tool in clinical practice.

Association of the Interaction Between Smoking and Depressive Symptom Clusters With Coronary Artery Calcification: The CARDIA Study

OBJECTIVE

Depressive symptom clusters are differentially associated with prognosis among patients with cardiovascular disease (CVD). Few studies have prospectively evaluated the association between depressive symptom clusters and risk of CVD. Previously, we observed that smoking and global depressive symptoms were synergistically associated with coronary artery calcification (CAC). The purpose of this study was to determine whether the smoking by depressive symptoms interaction, measured cumulatively over 25 years, differed by depressive symptom cluster (negative affect, anhedonia, and somatic symptoms) in association with CAC.

METHODS

Participants (N = 3,189: 54.5% female; 51.5% Black; average age = 50.1 years) were followed from 1985-1986 through 2010-2011 in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Smoking exposure was measured by cumulative cigarette pack-years (cigarette packs smoked per day × number of years smoking; year 0 through year 25). Depressive symptoms were measured using a 14-item, 3-factor (negative affect, anhedonia, somatic symptoms) model of the Center for Epidemiologic Studies Depression (CES-D) Scale (years 5, 10, 15, 20, and 25). CAC was assessed at year 25. Logistic regression models were used to evaluate the association between the smoking by depressive symptom clusters interactions with CAC ( = 0 vs. > 0), adjusted for CVD-related sociodemographic, behavioral, and clinical covariates.

RESULTS

907 participants (28% of the sample) had CAC > 0 at year 25. The depressive symptom clusters did not differ significantly between the two groups. Only the cumulative somatic symptom cluster by cumulative smoking exposure interaction was significantly associated with CAC > 0 at year 25 (p = .028). Specifically, adults with elevated somatic symptoms (score 9 out of 18) who had 10, 20, or 30 pack-years of smoking exposure had respective odds ratios (95% confidence intervals) of 2.06 [1.08, 3.93], 3.71 [1.81, 7.57], and 6.68 [2.87, 15.53], ps < .05. Negative affect and anhedonia did not significantly interact with smoking exposure associated with CAC >0, ps > .05.

CONCLUSIONS

Somatic symptoms appear to be a particularly relevant cluster of depressive symptomatology in the relationship between smoking and CVD risk.

Depressive symptoms and all-cause mortality in people with type 2 diabetes: a focus on potential mechanisms

BACKGROUND

Depression has been associated with increased all-cause mortality in people with type 2 diabetes.

AIMS

To test whether anhedonia, dysphoria and anxiety are differentially associated with all-cause mortality and examine symptom-specific behavioural or pathophysiological mechanisms.

METHOD

A total of 1465 people completed the Edinburgh Postnatal Depression Scale in 2005 and were followed until death or 31 December 2010. Cox regression analyses compared survival time for people with a low v. high baseline dysphoria/anhedonia/anxiety score and identified mediating mechanisms.

RESULTS

After a mean follow-up of 1878 days (s.d. = 306), 139 participants had died. At all time points, people with anhedonia had an almost twofold increased mortality risk compared with those without anhedonia. Physical activity met criteria for mediation. Symptoms of dysphoria and anxiety were not associated with survival time.

CONCLUSIONS

Symptoms of anhedonia predicted shorter survival time, whereas dysphoria/anxiety did not. Mechanistic pathways, in particular physical activity, should be explored further.

Management of depression after myocardial infarction

Depression in patients who have had a myocardial infarction is an important clinical problem because it is extremely common and because the comorbidity complicates depression treatment and worsens the cardiovascular prognosis. Studies of psychotherapy, exercise, pharmacotherapy, and collaborative care demonstrate that effective treatment of depression is possible but the strength of the effects seen in most studies is low, and cardiovascular and all-cause morbidity and mortality benefits have not been proven. Recent collaborative care studies have had promising outcomes. For pharmacotherapy, side effects, including bleeding and arrhythmia risks, require special attention. Recovery from depression is associated with better long-term cardiovascular prognosis, while treatment per se is not.

Acute coronary syndrome-associated depression: the salience of a sickness response analogy?

Depression emerging in conjunction with acute coronary syndrome (ACS) is thought to constitute a distinct high-risk phenotype with inflammatory determinants. This review critically examines the notion put forward in the literature that ACS-associated depression constitutes a meaningful subtype that is qualitatively different from depressive syndromes observed in psychiatric patients; and evaluates the salience of an analogy to the acute sickness response to infection or injury as an explanatory model. Specific features differentiating ACS-associated depression from other phenotypes are discussed, including differences in depression symptom profiles, timing of the depressive episode in relation to ACS, severity of the cardiac event, and associated immune activation. While an acute sickness response analogy offers a plausible conceptual framework, concrete evidence is lacking for inflammatory activity as the triggering mechanism. It is likely that ACS-associated depression encompasses several causative scenarios.

Characterising acute coronary syndrome-associated depression: Let the data speak

Depression in the context of acute coronary syndrome (ACS) is understood to confer increased morbidity and mortality risk. The pathophysiological mechanisms underlying this association remain poorly understood, although several candidates including inflammation, cardiac autonomic dysregulation, and behavioural factors are viewed as of key importance. No single bio-behavioural explanatory model of ACS-associated depression has emerged, likely due the substantial heterogeneity across both conditions. We studied 344 patients with ACS; 45 fulfilled diagnostic (DSM-IV) criteria for a major depressive episode occurring within 1-month of ACS, and 13 had ongoing major depression that pre-dated ACS and continued through to 1 month post-ACS. We employed two statistical methods (multinomial logistic regression; and latent class analysis) and a range of immunological, autonomic and nutritional markers in an attempt to characterise a biological basis for ACS-associated depression. Regression modelling failed to accurately predict categorical group membership of ACS-associated depression. An alternative data-driven approach produced a three-class solution, with the derived classes differing on measure of C-reactive protein, vitamin D, omega-6:omega-3 ratio, heart rate variability, and age (all p⩽0.004). The majority of participants with ACS-associated and ongoing depression were members of the class characterised by the greatest biological disturbance. Patients with depression differed from those without depression on a range of psychological trait and state variables; additionally reporting poorer sleep quality, higher levels of social isolation, and functional impairment, but had similar biological profiles. Patients with ongoing depression generally had higher scores on these psychological/behavioural measures. Our novel analytic approach identified a combination of biomarkers suggestive of a role for immune, autonomic, and nutritional pathways in the manifestation of depression during ACS, in the context of additional psychosocial and behavioural vulnerabilities. Further studies are required to confirm the causal role of these factors in perpetuating depression and increasing risk of poor-health outcomes.

Inpatient and outpatient costs in patients with coronary artery disease and mental disorders: a systematic review

Background

To systematically review in- and outpatient costs in patients with coronary artery disease (CAD) and comorbid mental disorders.

Methods

A comprehensive database search was conducted for studies investigating persons with CAD and comorbid mental disorders (Medline, EMBASE, PsycINFO, Psyndex, EconLit, IBSS). All studies were included which allowed a comparison of in- and outpatient health care costs (assessed either monetarily or in terms of health care utilization) of CAD patients with comorbid mental disorders (mood, anxiety, alcohol, eating, somatoform and personality disorders) and those without. Random effects meta-analyses were conducted and results reported using forest plots.

Results

The literature search resulted in 7,275 potentially relevant studies, of which 52 met inclusion criteria. Hospital readmission rates were increased in CAD patients with any mental disorder (pooled standardized mean difference (SMD) = 0.34 [0.17;0.51]). Results for depression, anxiety and posttraumatic stress disorder pointed in the same direction with heterogeneous SMDs on a primary study level ranging from −0.44 to 1.26. Length of hospital stay was not increased in anxiety and any mental disorder, while studies on depression reported heterogeneous SMDs ranging from −0.08 to 0.82. Most studies reported increased overall and outpatient costs for patients with comorbid mental disorders. Results for invasive procedures were non-significant respectively inconclusive.

Conclusions

Comorbid mental disorders in CAD patients are associated with an increased healthcare utilization in terms of higher hospital readmission rates and increased overall and outpatient health care costs. From a health care point of view, it is requisite to improve the diagnosis and treatment of comorbid mental disorders in patients with CAD to minimize incremental costs.

A dynamic view of comorbid depression and generalized anxiety disorder symptom change in chronic heart failure: the discrete effects of cognitive behavioral therapy, exercise, and psychotropic medication

PURPOSE

No previous study has reported upon comorbid depression and anxiety disorders and their treatment in heart failure (HF), which the current study has sought to document.

MATERIALS AND METHODS

Total 29 HF patients under psychiatric management underwent primary depression cognitive behavioral therapy (CBT; n = 15) or primary generalized anxiety disorder (GAD) CBT (n = 14), and participated in a community exercise program and standard physician care. Repeated measures analysis of variance assessed Patient Health Questionnaire (PHQ-9) and GAD-7 symptom change pre- and post-CBT treatment, and assessed the interaction effects of treatment type, exercise, anti-depressant and anxiolytic.

RESULTS

There was a significant time and treatment interaction effect that favored the primary GAD CBT group for reduction in PHQ symptoms (F(1, 24) = 4.52, p = 0.04). Analysis of PHQ-somatic symptoms also showed a significant main effect for participation in the exercise program (F(1, 24) = 4.21, p = 0.05) and a significant time and anxiolytic interaction (F(1, 24) = 3.98, p = 0.05). The average number of cardiac hospital readmissions favored the primary GAD CBT group (p = 0.05).

CONCLUSION

The findings support the use of multifaceted interventions in the rehabilitation of HF patients with comorbid psychiatric needs. Implications for Rehabilitation Comorbid depression and anxiety disorders are a clinical and research focus that deserves more attention in the treatment of heart failure patients. Cognitive behavioral therapy, exercise, and anxiolytic use was associated with significant changes in depression and anxiety though discrete effects were evident. Multifaceted interventions are most likely to be successful in the rehabilitation of HF patients with psychiatric needs.

Depression as a risk factor for poor prognosis among patients with acute coronary syndrome: systematic review and recommendations: a scientific statement from the American Heart Association

BACKGROUND

Although prospective studies, systematic reviews, and meta-analyses have documented an association between depression and increased morbidity and mortality in a variety of cardiac populations, depression has not yet achieved formal recognition as a risk factor for poor prognosis in patients with acute coronary syndrome by the American Heart Association and other health organizations. The purpose of this scientific statement is to review available evidence and recommend whether depression should be elevated to the status of a risk factor for patients with acute coronary syndrome.

METHODS AND RESULTS

Writing group members were approved by the American Heart Association's Scientific Statement and Manuscript Oversight Committees. A systematic literature review on depression and adverse medical outcomes after acute coronary syndrome was conducted that included all-cause mortality, cardiac mortality, and composite outcomes for mortality and nonfatal events. The review assessed the strength, consistency, independence, and generalizability of the published studies. A total of 53 individual studies (32 reported on associations with all-cause mortality, 12 on cardiac mortality, and 22 on composite outcomes) and 4 meta-analyses met inclusion criteria. There was heterogeneity across studies in terms of the demographic composition of study samples, definition and measurement of depression, length of follow-up, and covariates included in the multivariable models. Despite limitations in some individual studies, our review identified generally consistent associations between depression and adverse outcomes.

CONCLUSIONS

Despite the heterogeneity of published studies included in this review, the preponderance of evidence supports the recommendation that the American Heart Association should elevate depression to the status of a risk factor for adverse medical outcomes in patients with acute coronary syndrome.

Heart rate variability measurement and clinical depression in acute coronary syndrome patients: narrative review of recent literature

AIM

We aimed to explore links between heart rate variability (HRV) and clinical depression in patients with acute coronary syndrome (ACS), through a review of recent clinical research literature.

BACKGROUND

Patients with ACS are at risk for both cardiac autonomic dysfunction and clinical depression. Both conditions can negatively impact the ability to recover from an acute physiological insult, such as unstable angina or myocardial infarction, increasing the risk for adverse cardiovascular outcomes. HRV is recognized as a reflection of autonomic function.

METHODS

A narrative review was undertaken to evaluate state-of-the-art clinical research, using the PubMed database, January 2013. The search terms "heart rate variability" and "depression" were used in conjunction with "acute coronary syndrome", "unstable angina", or "myocardial infarction" to find clinical studies published within the past 10 years related to HRV and clinical depression, in patients with an ACS episode. Studies were included if HRV measurement and depression screening were undertaken during an ACS hospitalization or within 2 months of hospital discharge.

RESULTS

Nine clinical studies met the inclusion criteria. The studies' results indicate that there may be a relationship between abnormal HRV and clinical depression when assessed early after an ACS event, offering the possibility that these risk factors play a modest role in patient outcomes.

CONCLUSION

While a definitive conclusion about the relevance of HRV and clinical depression measurement in ACS patients would be premature, the literature suggests that these measures may provide additional information in risk assessment. Potential avenues for further research are proposed.

Depression as a risk factor for adverse outcomes in coronary heart disease

BACKGROUND

Depression is firmly established as an independent predictor of mortality and cardiac morbidity in patients with coronary heart disease (CHD). However, it has been difficult to determine whether it is a causal risk factor, and whether treatment of depression can improve cardiac outcomes. In addition, research on biobehavioral mechanisms has not yet produced a definitive causal model of the relationship between depression and cardiac outcomes.

DISCUSSION

Key challenges in this line of research concern the measurement of depression, the definition and relevance of certain subtypes of depression, the temporal relationship between depression and CHD, underlying biobehavioral mechanisms, and depression treatment efficacy.

SUMMARY

This article examines some of the methodological challenges that will have to be overcome in order to determine whether depression should be regarded as a key target of secondary prevention in CHD.

Depression and cardiovascular disease

Approximately one out of every five patients with cardiovascular disease (CVD) suffers from major depressive disorder (MDD). Both MDD and depressive symptoms are risk factors for CVD incidence, severity and outcomes. Great progress has been made in understanding potential mediators between MDD and CVD, particularly focusing on health behaviors. Investigators have also made considerable strides in the diagnosis and treatment of depression among patients with CVD. At the same time, many research questions remain. In what settings is depression screening most effective for patients with CVD? What is the optimal screening frequency? Which therapies are safe and effective? How can we better integrate the care of mental health conditions with that of CVD? How do we motivate depressed patients to change health behaviors? What technological tools can we use to improve care for depression? Gaining a more thorough understanding of the links between MDD and heart disease, and how best to diagnose and treat depression among these patients, has the potential to substantially reduce morbidity and mortality from CVD.

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease: a meta-analysis

Generalized anxiety disorder prevalence and comorbidity with depression in coronary heart disease patients remain unquantified. Systematic searching of Medline, Embase, SCOPUS and PsycINFO databases revealed 1025 unique citations. Aggregate generalized anxiety disorder prevalence (12 studies, N = 3485) was 10.94 per cent (95% confidence interval: 7.8-13.99) and 13.52 per cent (95% confidence interval: 8.39-18.66) employing Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria (random effects). Lifetime generalized anxiety disorder prevalence was 25.80 per cent (95% confidence interval: 20.84-30.77). In seven studies, modest correlation was evident between generalized anxiety disorder and depression, Fisher's Z = .30 (95% confidence interval: .19-.42), suggesting that each psychiatric disorder is best conceptualized as contributing unique variance to coronary heart disease prognosis.

Psychological depression and cardiac surgery: a comprehensive review

The psychological and neurological impact of cardiac surgery has been of keen empirical interest for more than two decades although reports showing the prognostic influence of depression on adverse outcomes lag behind the evidence documented in heart failure, myocardial infarction, and unstable angina. The paucity of research to date is surprising considering that some pathophysiological mechanisms through which depression is hypothesized to affect coronary heart disease (e.g., platelet activation, the inflammatory system, dysrhythmias) are known to be substantially influenced by the use of cardiopulmonary bypass. As such, cardiac surgery may provide a suitable exemplar to better understand the psychiatric mechanisms of cardiopathogenesis. The extant literature is comprehensively reviewed with respect to the deleterious impact of depression on cardiac and neuropsychological morbidity and mortality. Research to date indicates that depression and major depressive episodes increase major cardiovascular morbidity risk after cardiac surgery. The association between depressive disorders and incident delirium is of particular relevance to cardiac surgery staff. Contemporary treatment intervention studies are also described along with suggestions for future cardiac surgery research.

Depression, anxiety, and cardiac morbidity outcomes after coronary artery bypass surgery: a contemporary and practical review

Research to date indicates that the number of coronary artery bypass graft (CABG) surgery patients affected by depression (i.e., major, minor, dysthymia) approximates between 30% and 40% of all cases. A longstanding empirical interest on psychosocial factors in CABG surgery patients highlights an association with increased risk of morbidity in the short and longer term. Recent evidence suggests that both depression and anxiety increase the risk for mortality and morbidity after CABG surgery independent of medical factors, although the behavioral and biological mechanisms are poorly understood. Though neither depression nor anxiety seem to markedly affect neuropsychological dysfunction, depression confers a risk for incident delirium. Following a comprehensive overview of recent literature, practical advice is described for clinicians taking into consideration possible screening aids to improve recognition of anxiety and depression among CABG surgery patients. An overview of contemporary interventions and randomized, controlled trials are described, along with suggestions for future CABG surgery research.