Heart Rate and Heart Rate Variability Changes Are Not Related to Future Cardiovascular Disease and Death in People With and Without Dysglycemia: A Downfall of Risk Markers? The Whitehall II Cohort Study

Intensive Glycemic Treatment Mitigates Cardiovascular and Mortality Risk Associated With Cardiac Autonomic Neuropathy in Type 2 Diabetes

BACKGROUND

Hyperglycemia is one of the proposed risk factors for cardiac autonomic neuropathy (CAN). CAN is associated with increased cardiovascular and mortality risk. But it remains unclear whether cardiovascular and mortality risk associated with CAN is mitigated by intensive glycemic treatment.

METHODS AND RESULTS

This secondary analysis included 7866 patients from the ACCORDION (Action to Control Cardiovascular Risk in Diabetes Follow-On) study. CAN was defined using ECG-derived measures. End points included primary outcome (composite of cardiovascular events) and total deaths. During a median follow-up of 8.9 years, a total of 1341 cardiovascular events and 1364 all-cause deaths were ascertained. Compared with standard treatment, intensive treatment reduced risk of primary outcome and total deaths among patients with CAN but not among those without CAN. Compared with absence of CAN, the presence of CAN was associated with increased risk of primary outcome and total deaths in the standard group but not in the intensive group. Significant interactions were found between CAN status and treatment arms on risk of primary outcome and total deaths. Incidence rates per 100 person-years of primary outcome and total deaths were similar between patients without CAN and those with CAN undergoing intensive treatment.

CONCLUSIONS

Intensive glycemic treatment mitigates cardiovascular and mortality risk associated with CAN and may serve as an effective way in the management of CAN.

Meta-analysis on inflammation and autonomic nervous system of coronary heart disease combined with depression

OBJECTIVES

This meta-analysis aimed to explore the association between inflammatory factors, heart rate variability (HRV) and the coexistence of coronary heart disease (CHD) and depression.

DESIGN

Systematic review and meta-analysis. Complying with the Meta-analysis Of Observational Studies in Epidemiology statement.

DATA SOURCES

We searched PubMed, Web of Science and EMBASE for the data from the inception date to 16 March 2023.

ELIGIBILITY CRITERIA

We included cross-sectional and cohort studies with inclusion criteria: (1) patients with CHD; (2) depression measurement and (3) including inflammatory factors or cardiac biomarkers or HRV.

DATA EXTRACTION AND SYNTHESIS

Two authors searched the databases independently. The effect estimates and heterogeneity were synthesised by Review Manager V.5.3. Sensitivity analysis and publication bias were analysed by STATA software. The quantitative synthesis outcomes were presented by mean difference (MD) or standard MD (SMD) with 95% CI.

RESULTS

By searching the databases, we identified a total of 6750 articles. There were 22 articles left after selection, including 6344 participants. This meta-analysis indicated that patients with CHD with depression had higher levels of C reaction protein (CRP) (SMD 0.50, 95% CI (0.19 to 0.81), p=0.001), high-sensitivity C reactive protein (hs-CRP) (SMD 0.28, 95% CI (0.07 to 0.48), p=0.008), IL-6 (SMD 0.49, 95% CI (0.05 to 0.92), p=0.03) and a lower level of the mean RR interval and the SD of all RR intervals (SMD -0.64, 95% CI (-1.11 to -0.17), p=0.008), SD of the 5 min averages of all normal RR intervals (MD -12.77 ms, 95% CI (-21.20 to -4.33), p=0.003), overage of the SD of all normal RR intervals for each 5 min segment (MD -13.83 ms, 95% CI (-15.94 to -11.72), p<0.00001), root mean square of successive differences (MD: -8.02 ms, 95% CI (-13.62 to -2.43), p=0.005), proportion of adjacent cycles differing by >50 ms (pNN50) (SMD -0.86, 95% CI (-1.41 to -0.31), p=0.002), than those without depression.

CONCLUSIONS

This study underscores the association between elevated CRP, hs-CRP, IL-6 and lower HRV in patients with CHD with depression. It emphasises the importance of clinicians assessing CRP, hs-CRP, IL-6 and HRV in patients with CHD to potentially identify depressive conditions.

Prognostic Implications of Type 2 Diabetes Mellitus in Heart Failure with Mildly Reduced Ejection Fraction

BACKGROUND

Data regarding the characterization and outcomes of diabetics with heart failure with a mildly reduced ejection fraction (HFmrEF) is scarce. This study investigates the prevalence and prognostic impact of type 2 diabetes in patients with HFmrEF.

METHODS

Consecutive patients with HFmrEF (i.e., left ventricular ejection fraction 41-49% and signs and/or symptoms of HF) were retrospectively included at one institution from 2016 to 2022. Patients with type 2 diabetes (dia-betics) were compared to patients without (i.e., non-diabetics). The primary endpoint was all-cause mortality at 30 months. Statistical analyses included Kaplan-Meier, multivariable Cox regression analyses and propensity score matching.

RESULTS

A total of 2169 patients with HFmrEF were included. The overall prevalence of type 2 diabetes was 36%. Diabetics had an increased risk of 30-months all-cause mortality (35.8% vs. 28.6%; HR = 1.273; 95% CI 1.092-1.483; p = 0.002), which was confirmed after multivariable adjustment (HR = 1.234; 95% CI 1.030-1.479; p = 0.022) and propensity score matching (HR = 1.265; 95% CI 1.018-1.572; p = 0.034). Diabetics had a higher risk of HF-related rehospitalization (17.8% vs. 10.7%; HR = 1.714; 95% CI 1.355-2.169; p = 0.001). Finally, the risk of all-cause mortality was increased in diabetics treated with insulin (40.7% vs. 33.1%; log-rank p = 0.029), whereas other anti-diabetic pharmacotherapies had no prognostic impact in HFmrEF.

CONCLUSIONS

Type 2 diabetes is common and independently associated with adverse long-term prognosis in patients with HFmrEF.

Heart rate variability and cardiovascular diseases: A Mendelian randomization study

BACKGROUND

The causal relationship between heart rate variability and cardiovascular diseases and the associated events is still unclear, and the conclusions of current studies are inconsistent. We aimed to explore the relationship between heart rate variability and cardiovascular diseases and the associated events with the Mendelian randomization study.

METHODS

We selected normal-to-normal inter-beat intervals (SDNN), root mean square of the successive differences of inter-beat intervals (RMSSD) and peak-valley respiratory sinus arrhythmia or high-frequency power (pvRSA/HF) as the three sets of instrumental variables for heart rate variability. The outcome for cardiovascular diseases included essential hypertension, heart failure, angina pectoris, myocardial infarction, nonischemic cardiomyopathy and arrhythmia. Cardiac arrest, cardiac death and major coronary heart disease event were defined as the related events of cardiovascular diseases. The data for exposures and outcomes were derived from publicly available genome-wide association studies. Inverse variance weighted was used for the main causal estimation. Analyses of heterogeneity and pleiotropy were conducted using the Cochran Q test of Inverse variance weighted and MR-Egger, leave-one-out analysis, and MR-Pleiotropy Residual Sum and Outlier methods.

RESULTS

The Inverse variance weighted method indicated that genetically predicted pvRSA/HF was associated with the increased risk of cardiac arrest (odds ratio 2.02, 95% confidence interval 1.25-3.28, p = .004). The results were free of heterogeneity and pleiotropy. There were no outliers and the leave-one-out analysis proved that the results were reliable.

CONCLUSIONS

This study provides genetic evidence that pvRSA/HF is causally related to cardiac arrest.

Mental Stress and Cardiovascular Health-Part I

Epidemiological studies have shown that a substantial proportion of acute coronary events occur in individuals who lack the traditional high-risk cardiovascular (CV) profile. Mental stress is an emerging risk and prognostic factor for coronary artery disease and stroke, independently of conventional risk factors. It is associated with an increased rate of CV events. Acute mental stress may develop as a result of anger, fear, or job strain, as well as consequence of earthquakes or hurricanes. Chronic stress may develop as a result of long-term or repetitive stress exposure, such as job-related stress, low socioeconomic status, financial problems, depression, and type A and type D personality. While the response to acute mental stress may result in acute coronary events, the relationship of chronic stress with increased risk of coronary artery disease (CAD) is mainly due to acceleration of atherosclerosis. Emotionally stressful stimuli are processed by a network of cortical and subcortical brain regions, including the prefrontal cortex, insula, amygdala, hypothalamus, and hippocampus. This system is involved in the interpretation of relevance of environmental stimuli, according to individual’s memory, past experience, and current context. The brain transduces the cognitive process of emotional stimuli into hemodynamic, neuroendocrine, and immune changes, called fight or flight response, through the autonomic nervous system and the hypothalamic–pituitary–adrenal axis. These changes may induce transient myocardial ischemia, defined as mental stress-induced myocardial ischemia (MSIMI) in patients with and without significant coronary obstruction. The clinical consequences may be angina, myocardial infarction, arrhythmias, and left ventricular dysfunction. Although MSIMI is associated with a substantial increase in CV mortality, it is usually underestimated because it arises without pain in most cases. MSIMI occurs at lower levels of cardiac work than exercise-induced ischemia, suggesting that the impairment of myocardial blood flow is mainly due to paradoxical coronary vasoconstriction and microvascular dysfunction.