Is there a relationship between obesity, heart rate variability and inflammatory parameters in heart failure?

Enhancing Comprehensive Assessments in Chronic Heart Failure Caused by Ischemic Heart Disease: The Diagnostic Utility of Holter ECG Parameters

Background and Objectives: Chronic heart failure (CHF) caused by ischemic heart disease (IHD) is the leading cause of death worldwide and presents significant health challenges. Effective management of IHD requires prevention, early detection, and treatment to improve patient outcomes. This study aims to expand the diagnostic utility of various 24 h Holter ECG parameters, such as T-wave alternans (TWA), late ventricular potentials (LVPs), and heart rate variability (HRV) in patients with CHF caused by IHD. Additionally, we seek to explore the association between these parameters and other comorbid conditions affecting the prognosis of CHF patients. Materials and Methods: We conducted a prospective case-control study with 150 patients divided into two subgroups: 100 patients with CHF caused by IHD, and 50 patients in the control group. Data included medical history, physical examination, laboratory tests, echocardiography, and 24 h Holter monitoring. Results: Our comparative analysis demonstrated that both TWA and LVPs were significantly higher in patients with CHF compared to the control group (p < 0.01), indicating increased myocardial electrical vulnerability in CHF patients. Both time and frequency-domain HRV parameters were significantly lower in the CHF group. However, the ratio of NN50 to the total count of NN intervals (PNN50) showed a borderline significance (p = 0.06). While the low-frequency (LF) domain was significantly lower in CHF patients, the high-frequency (HF) domain did not differ significantly between groups. Acceleration and deceleration capacities were also significantly altered in CHF patients. Categorizing CHF patients by left ventricular ejection fraction (LVEF) revealed that the mean of the 5-min normal-to-normal intervals over the complete recording (SDNN Index) was significantly higher in patients with LVEF ≥ 50% compared to those with CHF with reduced EF and CHF with mildly reduced EF (p < 0.001), whereas the other HRV parameters showed no significant differences among the groups. Conclusions: Holter ECG parameters can become a reliable tool in the assessment of patients with CHF. The integration of multiple Holter ECG parameters, such as TWA, LVPs, and HRV, can significantly enhance the diagnostic assessment of CHF caused by IHD. This comprehensive approach allows for a more nuanced understanding of the patient's condition and potential outcomes.

Harmony in Chaos: Deciphering the Influence of Ischemic Cardiomyopathy and Non-Cardiac Comorbidities on Holter ECG Parameters in Chronic Heart Failure Patients: A Pilot Study

Background and Objective: In the landscape of heart failure, non-cardiac comorbidities represent a formidable challenge, imparting adverse prognostic implications. Holter ECG monitoring assumes a supplementary role in delineating myocardial susceptibility and autonomic nervous system dynamics. This study aims to explore the potential correlation between Holter ECG parameters and comorbidities in individuals with ischemic cardiomyopathy experiencing heart failure (HF), with a particular focus on the primary utility of these parameters as prognostic indicators. Materials and Methods: In this prospective inquiry, a cohort of 60 individuals diagnosed with heart failure underwent stratification into subgroups based on the presence of comorbidities, including diabetes, chronic kidney disease, obesity, or hyperuricemia. Upon admission, a thorough evaluation of all participants encompassed echocardiography, laboratory panel analysis, and 24 h Holter monitoring. Results: Significant associations were uncovered between diabetes and unconventional physiological indicators, specifically the Triangular index (p = 0.035) and deceleration capacity (p = 0.002). Pertaining to creatinine clearance, notable correlations surfaced with RMSSD (p = 0.026), PNN50 (p = 0.013), and high-frequency power (p = 0.026). An examination of uric acid levels and distinctive Holter ECG patterns unveiled statistical significance, particularly regarding the deceleration capacity (p = 0.045). Nevertheless, in the evaluation of the Body Mass Index, no statistically significant findings emerged concerning Holter ECG parameters. Conclusions: The identified statistical correlations between non-cardiac comorbidities and patterns elucidated in Holter ECG recordings underscore the heightened diagnostic utility of this investigative modality in the comprehensive evaluation of individuals grappling with HF. Furthermore, we underscore the critical importance of the thorough analysis of Holter ECG recordings, particularly with regard to subtle and emerging parameters that may be overlooked or insufficiently acknowledged.

Impact of Malnutrition on Clinical Outcomes of Acutely Hospitalised Heart Failure Patients at Two Tertiary Hospitals in Australia: An Observational Study

BACKGROUND

Malnutrition is common in patients with heart failure (HF) but is often neglected, despite guidelines suggesting that all hospitalised patients should undergo nutritional screening within 24-hours of admission.

AIMS

This study investigated the nutritional screening rates and determined the immediate and long-term clinical outcomes in patients with HF admitted at two tertiary hospitals in Australia.

METHODS

Nutritional screening was assessed by the Malnutrition Universal Screening Tool (MUST) completion rates. Patients were classified into two categories based on their MUST scores (0=low malnutrition risk and ≥1=at risk of malnutrition). Propensity-score-matching (PSM) was used to match 20 variables depending upon the risk of malnutrition. Clinical outcomes included the days-alive-and-out-of-hospital at 90 days of discharge (DAOH90), length of hospital stay, in-hospital, 30-day and 180-day mortality and 30-day readmissions.

RESULTS

There were 5,734 HF admissions between 2013-2020, of whom, only 789 (13.8%) patients underwent MUST screening. The mean (SD) age was 76.2 (14.0) years and 51.9% were males. Five-hundred and fifty-four (554) (70.2%) patients were at low malnutrition risk and 235 (29.8%) at risk of malnutrition. In HF patients, who were at risk of malnutrition, the DAOH90 were lower by 5.9 days (95% CI -11.49 to -0.42, p=0.035) and 180-day mortality was significantly worse (coefficient 0.10, 95% CI 0.02-0.18, p=0.007) compared to those who were at low risk of malnutrition. However, other clinical outcomes were similar between the two groups.

CONCLUSION

Nutrition screening is poor in hospitalised HF patients and long-term but not short-term clinical outcomes were worse in malnourished HF patients.

Heart rate variability is associated with left ventricular systolic, diastolic function and incident heart failure in the general population

BACKGROUND

HRV has mostly shown associations with systolic dysfunction and more recently, with diastolic dysfunction in Heart failure (HF) patients. But the role of sympathetic nervous system in changes of left ventricular (LV) systolic and diastolic function and new-onset HF has not been extensively studied.

METHODS

Among 3157 men and 4405 women free of HF and atrial fibrillation retrospectively included from the population-based Rotterdam Study, we used linear mixed models to examine associations of RR-interval differences and standard deviation of RR-intervals corrected for heart rate (RMSSDc and SDNNc) with longitudinal changes of LV ejection fraction (LVEF), E/A ratio, left atrial (LA) diameter, E/e' ratio. Afterwards, using cox regressions, we examined their association with new-onset HF.

RESULTS

Mean (SD) age was 65 (9.95) in men and 65.7 (10.2) in women. Every unit increase in log RMSSDc was accompanied by 0.75% (95%CI:-1.11%;-0.39%) and 0.31% (- 0.60%;-0.01%) lower LVEF among men and women each year, respectively. Higher log RMSSDc was linked to 0.03 (- 0.04;-0.01) and 0.02 (- 0.03;-0.003) lower E/A and also - 1.76 (- 2.77;- 0.75) and - 1.18 (- 1.99;-0.38) lower LVM index in both sexes and 0.72 mm (95% CI: - 1.20;-0.25) smaller LA diameters in women. The associations with LVEF in women diminished after excluding HF cases during the first 3 years of follow-up. During a median follow-up of 8.7 years, hazard ratios (95%CI) for incident HF were 1.34 (1.08;1.65) for log RMSSDc in men and 1.15 (0.93;1.42) in women. SDNNc showed similar associations.

CONCLUSIONS

Indices of HRV were associated with worse systolic function in men but mainly with improvement in LA size in women. Higher HRV was associated with higher risk of new-onset HF in men. Our findings highlight potential sex differences in autonomic function underlying cardiac dysfunction and heart failure in the general population.

Heart rate variability and inflammation: A meta-analysis of human studies

The inflammatory reflex is known as the body's primary defense against infection and has been implicated in a number of diseases. The magnitude of the inflammatory response is important, as an extreme or insufficient response can be differentially harmful to the individual. Converging evidence suggests that the autonomic nervous system (ANS) regulates the inflammatory reflex. Heart rate variability (HRV) can be separated into components that primarily reflect parasympathetic (PNS) or vagal activity (i.e., indices of vagally mediated HRV) and a combination of both sympathetic (SNS) and PNS influences. Given the physiological relation between the vagus and inflammatory processes, one would expect to find higher HRV, especially indices of vagally-mediated HRV, to be associated with decreased levels of inflammation via the cholinergic anti-inflammatory pathway. However, existing findings here are mixed, such that studies have also shown a positive association between indices of HRV and markers of inflammation. Therefore, the present meta-analysis aimed to synthesize existing studies, estimating the general direction and strength of the relationship between different indices of HRV and inflammatory markers. A systematic search of the literature yielded 2283 studies that were screened for inclusion eligibility (159 studies eligible for inclusion); in sum, 51 studies reported/provided adequate information for inclusion in meta-analyses. Results generally showed negative associations between indices of HRV and markers of inflammation. In this regard, the standard deviation of R-R intervals (SDNN) and power in the high frequency band of HRV (HF-HRV) showed the strongest and most robust associations with inflammatory markers compared to other time- and frequency-domain measures of HRV. Overall, we propose that indices of HRV can be used to index activity of the neurophysiological pathway responsible for adaptively regulating inflammatory processes in humans.

Relationship between diabetes mellitus and heart rate variability in community-dwelling elders

BACKGROUND AND OBJECTIVE

Diabetes mellitus is one of the most common non-communicable diseases (NCDs) and may influence the autonomic nervous system. This study aims to analyze the autonomic control, through heart rate variability (HRV), from community-dwelling elders with (DM+) and without diabetes mellitus (DM-).

MATERIALS AND METHODS

This cross-sectional study, in which 205 elders (≥ 60 years old), from the urban area of Aiquara municipality gave their written consent to participate. HRV data was collected through a Polar RS800CX monitor with a 5-min initial record at rest, followed by the command to quickly stand up.

RESULTS

The mean age was 71 years (SD, 7.32). The population was mostly made up of women 121 (59%), with low or no schooling 123 (60%), and low income 166 (81%). HRV analysis in a frequency domain showed no difference when comparing the two groups of DM+ and DM-. Henceforth in a time domain, the rMSSD showed a median value of 16.09 (interquartile range, 9.91-30.68); pNN50 median of 0.79 (interquartile range, 0.00-6.62), with a statistical significance between the group of DM+ and DM-.

CONCLUSIONS

There is a difference between the studied groups principally in what concerns the time domain, which reflects the parasympathetic activity, suggesting that elders with diabetes mellitus may have a worse parasympathetic control.

Interval training based on ventilatory anaerobic threshold increases cardiac vagal modulation and decreases high-sensitivity c-reative protein: randomized clinical trial in coronary artery disease

BACKGROUND

Autonomic dysfunction and inflammatory activity are involved in the development and progression of coronary artery disease (CAD), and exercise training has been shown to confer a cardiovascular benefit.

OBJECTIVE

To evaluate the effects that interval training (IT) based on ventilatory anaerobic threshold (VAT) has on heart rate variability (HRV) and high-sensitivity C-reactive protein (hs-CRP) levels, as well as the relationship between both levels, in patients with CAD and/or cardiovascular risk factors (RF).

METHOD

Forty-two men (aged 57.88±6.20 years) were divided into two training groups, CAD-T (n= 12) and RF-T (n= 10), and two control groups, CAD-C (n= 10) and RF-C (n=10). Heart rate and RR intervals in the supine position, cardiopulmonary exercise tests, and hs-CRP levels were measured before and after IT. HRV was analyzed by spectral and symbolic analysis. The CAD-T and RF-T underwent a 16-week IT program of three weekly sessions at training intensities based on the VAT.

RESULTS

In the RF-T, cardiac sympathetic modulation index and hs-CRP decreased (p<0.02), while cardiac parasympathetic modulation index increased (p<0.02). In the CAD-T, cardiac parasympathetic modulation index increased, while hs-CRP, systolic, and diastolic blood pressures decreased (p<0.02). Both control groups showed increase in hs-CRP parameters (p<0.02). There was a strong and significant association between parasympathetic and sympathetic modulations with hs-CRP.

CONCLUSION

The IT program based on the VAT promoted a decrease in hs-CRP associated with improvement in cardiac autonomic modulation.

N-terminal pro-B-type natriuretic peptide level inversely associates with metabolic syndrome in elderly persons

AIMS

Serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) was lower in the general population with metabolic syndrome (MetS). The aim of this study was to evaluate the relationship between MetS and fasting serum NT-proBNP concentration in elderly persons.

METHODS

Fasting blood samples were obtained from 84 elderly volunteers aged 65 years or older. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation.

RESULTS

Thirty-eight elderly persons (45.2%) had MetS. Fasting NT-proBNP level was negatively correlated with MetS among elderly patients (p = 0.001). Univariate linear regression analysis showed that age (r = 0.338; p = 0.002) was positively correlated with fasting serum log-NT-proBNP levels, while height (r = -0.253; p = 0.020), body weight (r = -0.238; p = 0.029), waist circumference (r = -0.270; p = 0.013), body fat mass (r = -0.356; p = 0.002) and triglyceride (r = -0.291; p = 0.007) were negatively correlated with fasting serum log-NT-proBNP levels among the elderly persons. Multivariate forward stepwise linear regression analysis of the significant variables showed that age (R2 change = 0.114, p = 0.011), triglyceride (R2 change = 0.118, p < 0.001), body fat mass (R2 change = 0.084, p < 0.001), and height (R2 change = 0.101, p < 0.001) were the independent predictor of fasting serum log-NT-proBNP levels in elderly persons.

CONCLUSIONS

NT-proBNP level is significantly reduced in elderly persons affected by MetS, and is significantly positively related to age, while negatively related to triglyceride, body fat mass, height in these subjects.

Relation of short-term heart rate variability to incident heart failure (from the Multi-Ethnic Study of Atherosclerosis)

Whether autonomic dysfunction predates the development of symptomatic heart failure (HF) or is simply a consequence of severe HF is unknown. We hypothesized that reduced heart rate variability (a marker of abnormal autonomic function) at baseline is associated with incident HF in subjects free of clinically recognized cardiovascular disease. In the Multi-Ethnic Study of Atherosclerosis (MESA), a population-based study of subclinical cardiovascular disease in adults aged 45 to 84 years, we measured the heart rate variability using a standard 30-second, 12-lead electrocardiogram to measure the standard deviation of normal-to-normal intervals (SDNN) and the root mean square of successive differences in RR intervals (RMSSD). During a median follow-up of 7.6 years, 95 participants developed HF (incidence rate 2.7/1,000 person-years). After adjusting for age, gender, and ethnicity, the hazard ratio for incident HF stratified by the RMSSD tertile was 2.4 (95% confidence interval 1.4 to 4.2) for the lowest tertile and 1.7 (95% confidence interval 1.0 to 3.2) for the middle tertile (highest tertile was the referent group; p for trend <0.001). The inverse association between the RMSSD and incident HF persisted after adjustment for additional covariates, including diabetes, systolic blood pressure, heart rate, subclinical atherosclerosis, left ventricular end-systolic volume, interim myocardial infarction, and high-sensitivity C-reactive protein (p for trend = 0.009). A similarly significant inverse association was also observed for SDNN. In conclusion, baseline autonomic dysfunction was a risk factor for the development of HF in a multiethnic cohort. These population-based findings implicate autonomic dysfunction in the pathogenesis of HF, and decreased short-term heart rate variability might be a novel form of stage B (asymptomatic) HF.

Association of cardiovascular risk using non-linear heart rate variability measures with the framingham risk score in a rural population

Cardiovascular risk can be calculated using the Framingham cardiovascular disease (CVD) risk score and provides a risk stratification from mild to very high CVD risk percentage over 10 years. This equation represents a complex interaction between age, gender, cholesterol status, blood pressure, diabetes status, and smoking. Heart rate variability (HRV) is a measure of how the autonomic nervous system (ANS) modulates the heart rate. HRV measures are sensitive to age, gender, disease status such as diabetes and hypertension and processes leading to atherosclerosis. We investigated whether HRV measures are a suitable, simple, noninvasive alternative to differentiate between the four main Framingham associated CVD risk categories. In this study we applied the tone-entropy (T-E) algorithm and complex correlation measure (CCM) for analysis of HRV obtained from 20 min. ECG recordings and correlated the HRV score with the stratification results using the Framingham risk equation. Both entropy and CCM had significant analysis of variance (ANOVA) results [F (172, 3) = 9.51; <0.0001]. Bonferroni post hoc analysis indicated a significant difference between mild, high and very high cardiac risk groups applying tone-entropy (p < 0.01). CCM detected a difference in temporal dynamics of the RR intervals between the mild and very high CVD risk groups (p < 0.01). Our results indicate a good agreement between the T-E and CCM algorithm and the Framingham CVD risk score, suggesting that this algorithm may be of use for initial screening of cardiovascular risk as it is noninvasive, economical and easy to use in clinical practice.

Heart rate variability today

Heart rate variability (HRV) non-invasively assesses the activity of the autonomic nervous system. During the past 30 years, an increasing number of studies have related the imbalance of the autonomic nervous system (as assessed by HRV) to several pathophysiogical conditions, particularly in the setting of cardiovascular disease. Sudden death, coronary artery disease, heart failure, or merely cardiovascular risk factors (smoking, diabetes, hyperlipidemia, and hypertension) are the best-known clinical circumstances that can affect and/or be affected by the autonomic nervous system. Analyses of HRV variables have been proposed as a component of the clinical evaluation for patient risk stratification due to its independent prognostic information. Yet the potential for HRV to be used widely in clinical practice remains to be established.

B-type natriuretic peptide increases after gastric bypass surgery and correlates with weight loss

BACKGROUND

Coronary artery disease is the primary cause of death in the United States, with obesity as a leading preventable risk factor. Previous studies have established the beneficial effect of Roux-en-Y gastric bypass on both weight and cardiac risk factors. Further assessment of cardiac function may be accomplished using B-type natriuretic peptide (BNP), which has demonstrated clinical utility in diagnosing congestive heart failure. This study aimed to assess changes in BNP after intentional weight loss through gastric bypass surgery.

METHODS

Plasma volume, weight, and BNP were measured preoperatively and at 3, 6, and 12 months postoperatively for 101 consecutive patients undergoing laparoscopic gastric bypass surgery by a single surgeon in an academic medical setting. Outcomes were compared by matched t-test. Multivariable linear regression and Pearson's correlation were used to examine predictors of pro-B-type natriuretic peptide (NT-proBNP) concentration.

RESULTS

The concentration of BNP increased significantly from a mean preoperative level of 50.5 ng/l to postoperative levels of 73.9 ng/l at 3 months (P=0.013), 74.3 ng/l at 6 months (P<0.001), and 156.3 ng/l at 12 months (P<0.001). In addition, excess weight loss was the only statistically significant predictor of increased BNP concentration (odds ratio, 1.483; P<0.05).

CONCLUSION

Gastric bypass leads to significant excess weight loss and surprisingly increased BNP concentrations. Correlation of BNP increase with weight loss suggests an additional novel mechanism for surgically induced weight loss.