Predicting 7-day survival using heart rate variability in hospice patients with non-lung cancers

How to properly evaluate cardiac vagal tone in oncology studies: a state-of-the-art review

Heart rate variability (HRV) analysis provides an assessment of cardiac vagal tone and consequently global cardiac health as well as systemic condition. In systemic diseases such as cancer and during treatments that affect the whole body, like chemotherapy, the vagus nerve activity is low and deregulated. Some studies focus on using HRV to predict mortality in oncology. However, in cancer patients, systemic alterations substantially increase artifacts during HRV measurement, especially atrial ectopic beats. Moreover, HRV may be altered by various factors (duration and time of measurement, breathing, drugs, and other confounding factors) that alter each metric in different ways. The Standard Deviation of all Normal to Normal intervals (SDNN) is the most commonly used metric to evaluate HRV in oncology, but it does not appear to be specific to the cardiac vagal tone. Thus, cardiac vagal activity diagnosis and vital prognosis of cancer patients can be biased. Our review presents the main HRV metrics that can be currently used in oncology studies and their links with vagus nerve and cancer. We present the influence of external factors and the required duration and time of measurement. Considering all these parameters, this review proposes seven key points for an assessment of HRV and cardiac vagal tone in patients with cancer.

The relationship between heart rate variability and TNM stage, co-morbidity, systemic inflammation and survival in patients with primary operable colorectal cancer

High vagal nerve activity, reliability measured by HRV, is considered protective in cancer, reducing oxidative stress, inflammation and opposing sympathetic nerve activity. The present monocentric study examines the relationship between HRV, TNM stage, co-morbidity, systemic inflammation and survival in patients who underwent potentially curative resections for colorectal cancer (CRC). Time-domain HRV measures, Standard Deviation of NN-intervals (SDNN) and Root Mean Square of Successive Differences (RMSSD), were examined as categorical (median) and continuous variables. Systemic inflammation was determined using systemic inflammatory grade (SIG) and co-morbidity using ASA. The primary end point was overall survival (OS) and was analysed using Cox regression. There were 439 patients included in the study and the median follow-up was 78 months. Forty-nine percent (n = 217) and 48% (n = 213) of patients were categorised as having low SDNN (< 24 ms) and RMSSD (< 29.8 ms), respectively. On univariate analysis, SDNN was not significantly associated with TNM stage (p = 0.830), ASA (p = 0.598) or SIG (p = 0.898). RMSSD was not significantly associated with TNM stage (p = 0.267), ASA (p = 0.294) or SIG (p = 0.951). Neither SDNN or RMSSD, categorical or continuous, were significantly associated with OS. In conclusion, neither SDNN or RMSSD were associated with TNM stage, ASA, SIG or survival in patients undergoing potentially curative surgery for CRC.

Association of heartbeat complexity with survival in advanced non-small cell lung cancer patients

Background

Previous studies have shown that the predictive value of traditional linear (time domain and frequency domain) heart rate variability (HRV) for the survival of patients with advanced non-small cell lung cancer (NSCLC) is controversial. Nonlinear methods, based on the concept of complexity, have been used to evaluate HRV, providing a new means to reveal the physiological and pathological changes in HRV. This study aimed to assess the association between heartbeat complexity and overall survival in patients with advanced NSCLC.

Methods

This study included 78 patients with advanced NSCLC (mean age: 62.0 ± 9.3 years). A 5-min resting electrocardiogram of advanced NSCLC patients was collected to analyze the following HRV parameters: time domain indicators, i.e., standard deviation of the normal-normal intervals (SDNN) and root mean square of successive interval differences (RMSSD); frequency domain indicators, i.e., total power (TP), low frequency power (LF), high frequency power (HF), and the ratio of LF to HF (LF/HF); nonlinear HRV indicators characterizing heartbeat complexity, i.e., approximate entropy (ApEn), sample entropy (SampEn), and recurrence quantification analysis (RQA) indexes: mean diagonal line length (Lmean), maximal diagonal line length (Lmax), recurrence rate (REC), determinism (DET), and shannon entropy (ShanEn).

Results

Univariate analysis revealed that the linear frequency domain parameter HF and nonlinear RQA parameters Lmax, REC, and DET were significantly correlated with the survival of advanced NSCLC patients (all p < 0.05). After adjusting for confounders in the multivariate analysis, HF, REC, and DET were found to be independent prognostic factors for the survival of patients with advanced NSCLC (all p < 0.05).

Conclusion

There was an independent association between heartbeat complexity and survival in advanced NSCLC patients. The nonlinear analysis method based on RQA may provide valuable additional information for the prognostic stratification of patients with advanced NSCLC and may supplement the traditional time domain and frequency domain analysis methods.

Prefrontally modulated vagal neuroimmunomodulation is associated with telomere length

Background

Accumulated senescent cells are proposed to be one of the main drivers of age-related pathology such as dementia and cancer through disruption of tissue structure and function. We recently proposed the Neuro-Immuno-Senescence Integrative Model (NISIM), which relates prefrontally modulated vagal tone and subsequent balance between vagal and sympathetic input to the spleen to inflammatory responses leading to generation of reactive oxygen species and oxidative telomere damage.

Aim

In this study, we assess inflammation as a mediator in the relationship between prefrontally modulated vagal tone and leukocyte telomere length (LTL). We also assess the relationship between a recently proposed index of vagal neuroimmunomodulation (vagal tone/inflammation ratio; NIM index) and telomere length.

Methods

This study uses participant data from a large nationally representative longitudinal study since 1974 with a total of 45,000 Norwegian residents so far. A sub-sample of 131 participants from which ultrashort recordings (30 s) of vagal tone, c reactive protein, and LTL could be obtained were included in the study. Relationships were analyzed with Pearson's correlations and hierarchical multiple linear regression using either vagal tone and CRP or the NIM index to predict telomere length.

Results

Vagal tone was a significant positive predictor of telomere length but this was not mediated by c reactive protein, even after controlling for confounders. The NIM index was a significant positive predictor of telomere length, also when controlling for confounders. In a follow-up analysis simultaneously comparing telomere length between groups with high and low values of vagal tone, and between groups with high and low NIM index values, telomere length was only significantly different between NIM index groups.

Conclusion

This is the first study suggesting that prefrontally modulated vagal neuroimmunomodulation is associated with telomere length thus supporting the NISIM. Results indicate that the NIM index is a more sensitive indicator of vagal neuroimmunomodulation than vagal tone and CRP in isolation.

Non-invasive prognostic biomarker of lung cancer patients with brain metastases: Recurrence quantification analysis of heart rate variability

Background: It has previously been shown that the time-domain characteristic of heart rate variability (HRV) is an independent prognostic factor for lung cancer patients with brain metastasis (LCBM). However, it is unclear whether the nonlinear dynamic features contained in HRV are associated with prognosis in patients with LCBM. Recurrence quantification analysis (RQA) is a common nonlinear method used to characterize the complexity of heartbeat interval time series. This study was aimed to explore the association between HRV RQA parameters and prognosis in LCBM patients.

Methods: Fifty-six LCBM patients from the Department of Radiation Oncology, the First Affiliated Hospital of Bengbu Medical College, were enrolled in this study. Five-minute ECG data were collected by a mini-ECG recorder before the first brain radiotherapy, and then heartbeat interval time series were extracted for RQA. The main parameters included the mean diagonal line length (Lmean), maximal diagonal line length (Lmax), percent of recurrence (REC), determinism (DET) and Shannon entropy (ShanEn). Patients were followed up (the average follow-up time was 19.2 months, a total of 37 patients died), and the relationships between the RQA parameters and survival of LCBM patients were evaluated by survival analysis.

Results: The univariate analysis showed that an Lmax of >376 beats portended worse survival in LCBM patients. Multivariate Cox regression analysis revealed that the Lmax was still an independent prognostic factor for patients with LCBM after adjusting for confounders such as the Karnofsky performance status (KPS) (HR = 0.318, 95% CI: 0.151–0.669, p = 0.003).

Conclusion: Reduced heartbeat complexity indicates a shorter survival time in patients with LCBM. As a non-invasive biomarker, RQA has the potential for application in evaluating the prognosis of LCBM patients.

Low Heart Rate Variability Predicts Poor Overall Survival of Lung Cancer Patients With Brain Metastases

Background

The aim of this prospective study was to evaluate the association between heart rate variability (HRV) and overall survival of lung cancer patients with brain metastases (LCBM).

Methods

Fifty-six LCBM patients were enrolled in this study. Five-minute electrocardiograms were collected before the time to first brain radiotherapy. HRV was analyzed quantitatively by using the time domain parameters, i.e., the standard deviation of all normal-normal intervals (SDNN) and the root mean square of successive differences (RMSSD). Survival time for LCBM patients was defined as from the date of HRV testing to the date of death or the last follow-up.

Results

In the univariate analysis, SDNN ≤ 13 ms (P = 0.003) and RMSSD ≤ 4.8 ms (P = 0.014) significantly predicted poor survival. Multivariate analysis confirmed that RMSSD ≤ 4.8 ms (P = 0.013, hazard ratio = 3.457, 95% confidence interval = 1.303–9.171) was also an independent negative prognostic factor after adjusting for mean heart rate, Karnofsky performance status, and number of brain metastases in LCBM patients.

Conclusion

Decreased RMSSD is independently associated with shorter survival time in LCBM patients. HRV might be a novel predictive biomarker for LCBM prognosis.

Psychoneuroendocrinological effects of music therapy versus mindfulness in palliative care: results from the 'Song of Life' randomized controlled trial

PURPOSE

Although research on psychosocial interventions in palliative care provided evidence for their effectiveness regarding patient-reported outcomes, few studies have examined their psychobiological effects yet. Therefore, the purpose of the present work as part of an overarching study was to investigate differential effects of music therapy versus mindfulness on subjective distress and both neuroendocrine and autonomic stress biomarkers.

METHODS

A total of 104 patients from two palliative care units were randomly assigned to three sessions of either music therapy or mindfulness. Before and after the second session (completed by 89 patients), participants rated their momentary distress and provided three saliva samples for cortisol and α-amylase analysis. Furthermore, photoplethysmography recordings were continuously assessed to calculate mean heart rate and heart rate variability. Data were analyzed using multilevel modeling of all available data and sensitivity analysis with multiply imputed data.

RESULTS

Between 67 and 75% of the maximally available data points were included in the primary analyses of psychobiological outcomes. Results showed a significant time*treatment effect on distress (b =  - 0.83, p = .02) indicating a greater reduction in the music therapy group. No interaction effects were found in psychobiological outcomes (all p > .05), but multilevel models revealed a significant reduction in cortisol (b =  - 0.06, p = .01) and mean heart rate (b =  - 7.89, p = .05) over time following either intervention.

CONCLUSION

Findings suggest a beneficial effect music therapy on distress while no differential psychobiological treatment effects were found. Future studies should continue to investigate optimal stress biomarkers for psychosocial palliative care research.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS)-DRKS00015308 (date of registration: September 7, 2018).

Objectifying the Subjective: The Use of Heart Rate Variability as a Psychosocial Symptom Biomarker in Hospice and Palliative Care Research

Measuring psychosocial symptoms in hospice and palliative care research is critical to understanding the patient and caregiver experience. Subjective patient-reported outcome tools have been the primary method for collecting these data in palliative care, and the growing field of biobehavioral research offers new tools that could deepen our understanding of psychosocial symptomatology. Here we describe one psychosocial biomarker, heart rate variability (HRV), and simple techniques for measurement in an adolescent and young adult cancer population that are applicable to palliative care studies. Complementing self-reported measures with objective biomarkers like HRV could facilitate a more nuanced understanding of physiologic and perceived well-being in patients with serious or life-limiting illness and inform future "precision supportive care" in hospice and palliative medicine.

Is pre-operative heart rate variability a prognostic indicator for overall survival and cancer recurrence in patients with primary colorectal cancer?

Background

Heart Rate Variability (HRV) represents efferent vagus nerve activity which is suggested to be inversely related to fundamental mechanisms of tumorigenesis and to be a predictor of prognosis in various types of cancer. HRV is also believed to predict the occurrence and severity of post-operative complications. We aimed to determine the role of pre-operative HRV as a prognostic factor in overall and cancer free survival in patients with colorectal cancer.

Methods

Retrospective analysis was performed in a detailed dataset of patients diagnosed with primary colorectal cancer between January 2010 and December 2016, who underwent curative surgical treatment. HRV was measured as time-domain parameters (SDNN (Standard Deviation of NN-intervals) and RMSSD (Root Mean Square of Successive Differences)) based on pre-operative 10 second ECGs. Groups were created by baseline HRV: Low HRV (SDNN <20ms or RMSSD <19ms) and normal HRV (SDNN ≥20ms or RMSSD ≥19ms). Primary endpoints were overall and cancer free survival.

Results

A total of 428 patients were included in this study. HRV was not significantly associated with overall survival (SDNN <20ms vs SDNN ≥20ms:24.4% vs 22.8%, adjusted HR = 0.952 (0.607–1.493), p = 0.829; RMSSD <19ms vs RMSSD ≥19ms:27.0% vs 19.5%, adjusted HR = 1.321 (0.802–2.178), p = 0.274) or cancer recurrence (SDNN <20ms vs ≥20ms:20.1% vs 18.7%, adjusted HR = 0.976 (0.599–1.592), p = 0.924; RMSSD <19ms vs ≥19ms, 21.5% vs 16.9%, adjusted HR = 1.192 (0.706–2.011), p = 0.511). There was no significant association between HRV and CEA-level at one year follow-up, or between HRV and occurrence of a post-operative complication or the severity of post-operative complications.

Conclusions

Heart rate variability was not associated with overall or cancer free survival in patients with primary colorectal cancer who underwent curative surgical treatment. These results do not align with results found in studies including only patients with advanced cancer, which suggests that there is only an association in the other direction, cancer causing low HRV.

Shock Index: A Simple and Effective Clinical Adjunct in Predicting 60-Day Mortality in Advanced Cancer Patients at the Emergency Department

Deciding between palliative and overly aggressive therapies for advanced cancer patients who present to the emergency department (ED) with acute issues requires a prediction of their short-term survival. Various scoring systems have previously been studied in hospices or intensive care units, though they are unsuitable for use in the ED. We aim to examine the use of a shock index (SI) in predicting the 60-day survival of advanced cancer patients presenting to the ED. Identified high-risk patients and their families can then be counseled accordingly. Three hundred and five advanced cancer patients who presented to the EDs of three tertiary hospitals were recruited, and their data retrospectively analyzed. Relevant data regarding medical history and clinical presentation were extracted, and respective shock indices calculated. Multivariate logistic regression analyses were performed. Receiver operating characteristic (ROC) curves were plotted to evaluate the predictive performance of the SI. Nonsurvivors within 60 days had significantly lower body temperatures and blood pressure, as well as higher pulse rates, respiratory rates, and SI. Each 0.1 SI increment had an odds ratio of 1.39 with respect to 60-day mortality. The area under the ROC curve was 0.7511. At the optimal cut-off point of 0.94, the SI had 81.38% sensitivity and 73.11% accuracy. This makes the SI an ideal evaluation tool for rapidly predicting the 60-day mortality risk of advanced cancer patients presenting to the ED. Identified patients can be counseled accordingly, and they can be assisted in making informed decisions on the appropriate treatment goals reflective of their prognoses.

Greater Well-Being in More Physically Active Cancer Patients Who Are Enrolled in Supportive Care Services

Background: Cancers are one of the leading causes of mortality worldwide. Cancer patients are increasingly seeking integrative care clinics to promote their health and well-being during and after treatment. Aim: To examine relationships between physical activity (PA) and quality of life (QoL) in a sample of cancer patients enrolling in integrative care in a supportive care clinic. Also, to explore circulating inflammatory biomarkers and heart rate variability (HRV) in relationship to PA and QoL. Methods: A cross-sectional design of adult patients who sought care in the InspireHealth clinic, Vancouver, British Columbia, Canada. Patients with complete PA data (n = 118) answered psychosocial questionnaires, provided blood samples, and received HRV recordings before enrollment. Patients were stratified into “less” versus “more” active groups according to PA guidelines (150 minutes of moderate or 75 minutes of vigorous PA or an equivalent combination). Results: Breast (33.1%) and prostate (10.2%) cancers were the most prevalent primary diagnoses. Patients engaging in more PA reported better physical (U = 1265.5, P = .013), functional (U = 1306.5, P = .024), and general QoL (U = 1341, P = .039), less fatigue (U = 1268, P = .014), fewer physical cancer-related symptoms (U = 2.338, P = .021), and less general distress (U = 2.061, P = .021). Between PA groups, type of primary cancer diagnosis differed (χ² = 41.79, P = .014), while stages of cancer did not (χ² = 3.95, P = .412). Fewer patients reported depressed mood within the more active group (χ² = 6.131, P = .047). More active patients were also less likely to have ever used tobacco (χ² = 7.41, P = .025) and used fewer nutritional supplements (χ² = 39.74, P ≤ .001). An inflammatory biomarker index was negatively correlated with vigorous PA (r_s = −0.215, P = .022). Multivariable linear regression (R² = 0.71) revealed that age (β = 0.22; P = .001), fatigue (β = −0.43; P ≤ .001), anxiety (β = −0.14; P = .048), and social support (β = 0.38; P = .001) were significant correlates of QoL.

The Role of the Vagus Nerve in Cancer Prognosis: A Systematic and a Comprehensive Review

This article reviews the role of the vagus nerve in tumor modulation and cancer prognosis. We present a systematic review of 12 epidemiological studies examining the relationship between heart rate variability, the main vagus nerve index, and prognosis in cancer patients (survival and tumor markers). These studies show that initially high vagal nerve activity predicts better cancer prognosis, and, in some studies, independent of confounders such as cancer stage and treatments. Since the design of the epidemiological studies is correlational, any causal relationship between heart rate variability and cancer prognosis cannot be inferred. However, various semi-experimental cohort studies in humans and experimental studies in animals have examined this causal relationship. The second part of this paper presents a comprehensive review including human and animal cohort and experimental studies showing that vagotomy accelerates tumor growth, while vagal nerve activation improves cancer prognosis. Based on all reviewed studies, it is concluded that the evidence supports a protective role of the vagus nerve in cancer and specifically in the metastatic stage.

Heart Rate Variability as a Prognostic Factor for Cancer Survival - A Systematic Review

An increasing cancer incidence affecting any age and social class is putting serious strain on populations and health care systems around the world. This systematic literature search aims (i) to examine the correlation of heart rate variability (HRV) and cancer patients' prognosis, (ii) to examine the relationship of HRV and clinicopathological features, and (iii) to compare HRV between different patient groups, and between patient and control groups. We conducted a systematic literature review following the PRISMA Statement. We searched the PubMed and EMBASE databases for publications released by December 2017. The search terms were: "cancer" AND "heart rate variability" AND "human" NOT "animal" NOT "review." A total of 19 studies were finally included in this review. Most publications were high-quality observational studies. The studies showed that higher HRV correlated positively with patients' progression of disease and outcome. Thus, we conclude that individuals with higher HRV and advanced coping mechanisms seem to have a better prognosis in cancer progression. HRV appears to be a useful aspect to access the general health status of cancer patients.

The Relationship between a New Biomarker of Vagal Neuroimmunomodulation and Survival in Two Fatal Cancers

BACKGROUND

The vagus nerve may slow tumor progression because it inhibits inflammation. This study examined the relationship between a new vagal neuroimmunomodulation (NIM) index and survival in fatal cancers.

METHOD

We retroactively derived markers of vagal nerve activity indexed by heart rate variability (HRV), specifically the root mean square of successive differences (RMSSD), from patients' electrocardiograms near diagnosis. The NIM index was the ratio of RMSSD to C-reactive protein levels (RMSSD/CRP). Sample 1 included 202 Belgian patients with advanced pancreatic cancer (PC), while sample 2 included 71 Belgian patients with non-small cell lung cancer (NSCLC). In both samples, we examined the overall survival, while in sample 2, we additionally examined the survival time in deceased patients.

RESULTS

In PC patients, in a multivariate Cox regression controlling for confounders, the NIM index had a protective relative risk (RR) of 0.68 and 95% confidence interval (95% CI) of 0.51-0.92. In NSCLC patients, the NIM index also had a protective RR of 0.53 and 95% CI of 0.32-0.88. Finally, in NSCLC, patients with a higher NIM index survived more days (475.2) than those with lower NIM (285.1) (p < 0.05).

CONCLUSIONS

The NIM index, reflecting vagal modulation of inflammation, may be a new independent prognostic biomarker in fatal cancers.

The Role of Heart Rate Variability in Advanced Non-Small-Cell Lung Cancer Patients

Aim

Several recent studies have suggested that assessing heart rate variability (HRV) is an easy method for obtaining prognostic information on cancer patients; however, these studies had limitations such as uncontrolled confounders and small numbers in a heterogeneous group. The intention of our study was to explore and validate the role of HRV variables in patients with advanced non-small-cell lung cancer (NSCLC).

Method

A total of 167 patients who were eligible for HRV testing were consecutively enrolled from a regional hospital in South Korea. Demographic and clinical variables, including the Eastern Cooperative Oncology Group (ECOG) performance status grade, NSCLC stage, therapeutic intervention, and other data were also recorded. The effects of time-domain and frequency-domain indices of HRV were compared with other clinical factors to determine overall survival.

Results

Among the HRV parameters, standard deviation of all normal-to-normal intervals (SDNN) significantly predicted poor survival by univariate analysis. However, multivariate analysis revealed that it was not an independent prognosticator for survival in NSCLC patients, as the HRV parameters significantly correlated with the ECOG performance status grade.

Conclusion

HRV variables should be used to monitor advanced NSCLC patients’ general well-being and ability to perform the activities of daily living rather than to predict their overall survival.

Insomnia and Autonomic Function Predict Well-Being in Patients Receiving Palliative Care

BACKGROUND

The improvement of health-related quality of life (HRQOL) is one of the main treatment goals in end-of-life care. Although definitions and conceptualizations remain heterogeneous, many researchers proposed HRQOL to be considered as subjective patient well-being. However, research on its determinants in palliative care is rare, and little is known about the interplay between psychological and biological variables.

OBJECTIVE

The aim of this study was to explain differences in terminally ill patients' acute well-being (AWB) by use of a multimethod approach, examining both self-ratings and physiological predictors.

SETTING/SUBJECTS

The study was conducted on a palliative care unit in Heidelberg, Germany. A total of 69 adult patients receiving palliative care were included in the analysis.

MEASUREMENTS

Patients filled out the EORTC QLQ-C15-PAL questionnaire and an additional single-item visual analogue scale on AWB. In addition, we recorded a five-minute segment of beat-to-beat fluctuations of heart rate (i.e., heart rate variability, HRV) and calculated three indices of cardiac autonomic function: mean heart rate, the root mean square of successive differences, and the standard deviation of normal-to-normal (SDNN) intervals. Exploratory, multiple regression analyses were used to identify significant predictors among the QLQ subscales and HRV parameters.

RESULTS

Insomnia (p < 0.001) and SDNN (p < 0.001) were significantly associated with AWB and together explained 26.3% of the variance. All other predictors including pain, fatigue, and physical functioning failed to reach significance (all p > 0.05).

CONCLUSION

Both autonomic dysfunction and sleep disturbances independently explained differences in patient's AWB among terminally ill patients. Their role within the concept of quality of life needs to be further addressed in future studies.

Music Therapy in Palliative Care

BACKGROUND

Music therapy has been used successfully for over 30 years as part of palliative care programs for severely ill patients. There is nonetheless a lack of high-quality studies that would enable an evidence-based evaluation of its psychological and physiological effects.

METHODS

In a randomized controlled trial, 84 hospitalized patients in palliative care were assigned to one of two treatment arms--music therapy and control. The music therapy intervention consisted of two sessions of live music-based relaxation exercises; the patients in the control group listened to a verbal relaxation exercise. The primary endpoints were self-ratings of relaxation, well-being, and acute pain, assessed using visual analog scales. Heart rate variability and health-related quality of life were considered as secondary outcomes. The primary data analysis was performed according to the intention-to-treat principle.

RESULTS

Analyses of covariance revealed that music therapy was more effective than the control treatment at promoting relaxation (F = 13.7; p <0.001) and well-being (F = 6.41; p = 0.01). This effect was supported by a significantly greater increase in high-frequency oscillations of the heart rate (F = 8.13; p = 0.01). Music therapy did not differ from control treatment with respect to pain reduction (F = 0.4; p = 0.53), but it led to a significantly greater reduction in the fatigue score on the quality-of-life scale (F = 4.74; p = 0.03).

CONCLUSION

Music therapy is an effective treatment with a low dropout rate for the promotion of relaxation and well-being in terminally ill persons undergoing palliative care.

Neural circuitry and immunity

Research during the last decade has significantly advanced our understanding of the molecular mechanisms at the interface between the nervous system and the immune system. Insight into bidirectional neuro-immune communication has characterized the nervous system as an important partner of the immune system in the regulation of inflammation. Neuronal pathways, including the vagus nerve-based inflammatory reflex, are physiological regulators of immune function and inflammation. In parallel, neuronal function is altered in conditions characterized by immune dysregulation and inflammation. Here, we review these regulatory mechanisms and describe the neural circuitry modulating immunity. Understanding these mechanisms reveals possibilities to use targeted neuromodulation as a therapeutic approach for inflammatory and autoimmune disorders. These findings and current clinical exploration of neuromodulation in the treatment of inflammatory diseases define the emerging field of Bioelectronic Medicine.

Trajectories of Terminally Ill Patients' Cardiovascular Response to Receptive Music Therapy in Palliative Care

CONTEXT

Relaxation interventions are frequently used to promote symptom relief in palliative care settings, but little is known about the underlying mechanisms.

OBJECTIVES

The present analysis aimed at examining the psychophysiological pathways of terminally ill patients' cardiovascular response to a live music therapy vs. prerecorded mindfulness exercise.

METHODS

Eighty-four patients of a palliative care unit were randomly assigned to either of the two interventions. Multilevel modeling was used to analyze trajectories of physiological change. Vagally mediated heart rate variability (VM-HRV) and blood volume pulse amplitude (BVP-A) served as indices of autonomic nervous system response. Participants' gender, age, baseline scores, self-rated pain, and assignment to treatment were entered to the models as predictors.

RESULTS

Both VM-HRV and BVP-A showed significant linear and quadratic trends over time, as well as substantial heterogeneity among individuals' trajectories. Baseline scores, pain, and treatment significantly accounted for random variation in VM-HRV intercepts. BVP-A levels were significantly higher in women than in men. Moreover, assignment to treatment significantly accounted for differences in the linear slopes of peripheral blood flow.

CONCLUSION

Higher levels of VM-HRV in the music therapy group highlight the importance of a therapeutic relationship for the effectiveness of relaxation interventions in end-of-life care settings. Music therapy caused significantly stronger reductions of vascular sympathetic tone and, therefore, may be indicated in the treatment of pain and stress-related symptoms in palliative care. Initial self-ratings of pain moderated patients' physiological response and need to be taken into account in clinical practice and future theory building.

Heart rate variability measure in breast cancer patients and survivors: A systematic review

PURPOSE

In the current study, we aimed to review literature findings showing the clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in breast cancer (BC) patients and survivors.

METHODS

We conducted a systematic review according to The PRISMA Statement in Medline, Scopus and Web of Science (_-2015) databases. The search was limited to articles in English language, published in peer-reviewed journals, and with adult age samples only (e.g., women, patients, or survivors, diagnosed with BC in any stage). We included observational studies and randomized trials. Detailed heart rate variability analysis (instruments, data collection protocol, and analysis methods) was required. Search terms included autonomic nervous system, heart rate variability, sympathetic and parasympathetic nervous system, autonomic dysfunction, vagal nervous and breast neoplasms, breast cancer and breast tumor.

RESULTS

Twelve studies were included in this review. The clinical importance of cardiac autonomic modulation assessed by heart rate variability analysis in BC patients and survivors is demonstrated by association with effects of BC surgery, and treatments, and the adverse effects of surgery and treatments on survivors (e.g., cardiotoxicity, fatigue, and stress).

LIMITATIONS

The strength of evidence of included studies is low: small samples size and heterogeneity, presence of confounders, and observational studies design.

CONCLUSIONS

The heart rate variability analysis could be used as a complementary non-invasive tool for the early diagnosis and better prognosis of autonomic dysfunction, and survival in BC patients. There are many potential clinical applications of heart rate variability analysis in BC patients, and the employment of such approaches could lead to lower impairment of autonomic function in this individuals.

Shock Index and Decreased Level of Consciousness as Terminal Cancer Patients' Survival Time Predictors: A Retrospective Cohort Study

CONTEXT

Predicting prognosis using noninvasive and objective tools may facilitate end-of-life decisions for terminal cancer patients, their families, and other health care professionals.

OBJECTIVES

To investigate if the shock index (SI), along with decreased level of consciousness (DLOC), is a reliable tool for predicting short-term survival time in terminal cancer patients.

METHODS

A two-part retrospective cohort study was performed on 670 consecutive adult hospice patients. Part 1 of the study was performed to investigate the reliability of SI and DLOC on admission and to make a simple tool for predicting survival time. Part 2 of the study was to validate the tool's reproducibility and analyze the correlation between SI, DLOC, and survival time.

RESULTS

In Part 1, multivariate Cox proportional hazards analyses for all study patients revealed that SI ≥ 1.0 in patients with DLOC was a significant risk factor of death (hazard ratio 3.08; 95% CI 1.72-5.53; P = 0.000). Generalized additive models confirmed that DLOC patients with SI = 1.0 had 9.58 days of mean survival time (MST). Receiver operating characteristic curve analyses of SI in patients with DLOC revealed that a survival time of less than three days was most reliably predicted. In Part 2, an increase in SI statistically decreased survival time. The upper 95% CIs of the calculated mean survival time for DLOC patients with SI ≥ 1.0 were less than one week. Bootstrap analyses revealed that the 95% CIs of the predicted survival time were 4.54-6.18 days in DLOC patients with SI = 1.0.

CONCLUSION

An SI ≥ 1.0 along with DLOC is a highly reliable tool for predicting short-term survival time in terminal cancer patients.

Probabilistic modeling of short survivability in patients with brain metastasis from lung cancer

The prediction of substantially short survivability in patients is extremely risky. In this study, we proposed a probabilistic model using Bayesian network (BN) to predict the short survivability of patients with brain metastasis from lung cancer. A nationwide cancer patient database from 1996 to 2010 in Taiwan was used. The cohort consisted of 438 patients with brain metastasis from lung cancer. We utilized synthetic minority over-sampling technique (SMOTE) to solve the imbalanced property embedded in the problem. The proposed BN was compared with three competitive models, namely, naive Bayes (NB), logistic regression (LR), and support vector machine (SVM). Statistical analysis showed that performances of BN, LR, NB, and SVM were statistically the same in terms of all indices with low sensitivity when these models were applied on an imbalanced data set. Results also showed that SMOTE can improve the performance of the four models in terms of sensitivity, while keeping high accuracy and specificity. Further, the proposed BN is more effective as compared with NB, LR, and SVM from two perspectives: the transparency and ability to show the relation of factors affecting brain metastasis from lung cancer; it allows decision makers to find the probability despite incomplete evidence and information; and the sensitivity of the proposed BN is the highest among all standard machine learning methods.

Heart Rate Variability in Breast Cancer Survivors After the First Year of Treatments: A Case-Controlled Study

The same aggressive treatments that have led to a reduction in the breast cancer may also have adverse effects on cardiac autonomic balance. The objective of this study was to compare heart rate variability (HRV) between breast cancer survivors in the first year posttreatment and healthy women, controlling for known confounders. This descriptive case-controlled study included 22 breast cancer survivors and 22 healthy age- and sex-matched controls. Short-term HRV was measured using an accepted methodology to assess the cardiac autonomic balance. One-way analysis of covariance results revealed that heart rate was significantly higher (F = 15.86, p < .001) and the standard deviation of normal-to-normal (NN) interval (F = 19.93, p = .001), square root of mean squared differences of successive NN intervals (F = 18.72, p = .001), HRV index (F = 5.44, p = .025), and high-frequency (F = 5.77, p = .03) values were significantly lower in the breast cancer survivors than in the matched controls. The principal finding of the presence of a cardiovascular imbalance in breast cancer survivors in comparison to healthy age-matched controls suggests that HRV study could be a clinically useful tool to detect cardiovascular disease in early-stage breast cancer survivors.