Sympathetic activation and heart rate thresholds for cardiovascular risk in chronic kidney disease

Biomarker for cardiorenal syndrome risk in patients with liver cirrhosis and type 2 diabetes in Saudi Arabia

OBJECTIVES

To evaluate the correlation between different attributes, levels of biomarkers, and the probability of developing cardiorenal syndrome (CRS) in patients who have been diagnosed with type 2 diabetes mellitus (T2DM) and liver cirrhosis (LC). The hypothesis suggests that liver illness may be linked to renal impairment, cardiac dysfunction, and the development of cardiorenal syndrome METHODS: The current study retrospectively assessed the medical records of patients who had LC and T2DM diagnoses and were hospitalized at Al Madina Al Munwara hospitals in 2022 and 2023.

RESULTS

This research investigated T2DM patients with physician-confirmed to have LC. Poor glycemic control is indicated by high blood glucose and glycated hemoglobin (HbA1c) readings in research participants. High blood pressure, atherogenic plasma indicator (AIP), and obesity plagued most of these individuals. High creatinine, moderate estimated Glomerular Filtration Rate (eGFR) decline, and a modest urinary albumin-to-creatinine (UACR) rise were the most prevalent variables in LC and T2DM patients. Cardiorenal syndrome risk factors, including elevated blood pressure, triglyceride levels, body mass index (BMI), and high-sensitivity C-reactive protein (hs-CRP) concentrations, were identified through logistic regression. It has been demonstrated that the prevalence of these risk factors increases with age; women may be at a greater risk for developing CRS. Specific biomarker evaluations classified 108 (22.6%) LC and T2DM patients at high risk for chronic kidney disease (CKD), 100 (20%) at risk for cardiovascular disease (CVD), and 91 (18.2%) at risk for CRS.

CONCLUSION

The current assessment included 500 patients with T2DM and LC. The risk factors for CRS identified in this study included elevated cholesterol and triglyceride levels, high BMI, and elevated blood pressure, with age being a significant factor, particularly in female patients. Early identification of these characteristics in patients with LC and T2DM could aid in mitigating the progression of chronic illnesses and their associated complications.

Blood pressure reduction after renal denervation in patients with or without chronic kidney disease

Background

Renal denervation (RDN) has emerged as an adjacent option for the treatment of hypertension. This analysis of the Erlanger registry aimed to compare the blood pressure (BP)-lowering effects and safety of RDN in patients with and without chronic kidney disease (CKD).

Methods

In this single-center retrospective analysis, 47 patients with and 127 without CKD underwent radiofrequency-, ultrasound- or alcohol-infusion-based RDN. Office and 24-h ambulatory BP and estimated glomerular filtration rate (eGFR) were measured at baseline, and after 6 and 12 months.

Results

A total of 174 patients with a mean age of 59.0 ± 10 years were followed up for 12 months. At baseline, mean eGFR was 55.8 ± 21 mL/min/1.73 m2 in patients with CKD and 87.3 ± 13 mL/min/1.73 m2 in patients without CKD. There was no significant eGFR decline in either of the groups during 12 months of follow-up. In patients without CKD, office systolic and diastolic BP were reduced by -15.3 ± 17.5/-7.9 ± 10.8 mmHg 6 months after RDN and by -16.1 ± 18.2/-7.7 ± 9.6 mmHg 12 months after RDN. In patients with CKD, office systolic and diastolic BP were reduced by -10.7 ± 24.0/-5.8 ± 13.2 mmHg 6 months after RDN and by -15.1 ± 24.9/-5.9 ± 12.9 mmHg 12 months after RDN. Accordingly, in patients without CKD, 24-h ambulatory systolic and diastolic BP were reduced by -7.2 ± 15.8/-4.9 ± 8.8 mmHg 6 months after RDN and by -9.0 ± 17.0/-6.2 ± 9.8 mmHg 12 months after RDN. In patients with CKD, 24-h systolic and diastolic BP were reduced by -7.4 ± 12.9/-4.2 ± 9.9 mmHg 6 months after RDN and by -8.0 ± 14.0/-3.6 ± 9.6 mmHg 12 months after RDN. There was no difference in the reduction of office and 24-h ambulatory BP between the two groups at any time point (all P > .2). Similar results have been found for the 6 months data. With exception of rare local adverse events, we did not observe any safety signals.

Conclusion

According to our single-center experience, we observed a similar reduction in 24-h, day and night-time ambulatory BP as well as in-office BP in patients with and without CKD at any time point up to 12 months. We conclude that RDN is an effective and safe treatment option for patients with hypertension and CKD.

High blood pressure with elevated resting heart rate: a high risk "Sympathetic" clinical phenotype

Epidemiological studies have unequivocally shown that elevated heart rate values measured at rest have an adverse prognostic impact in the hypertensive patient, being associated with an increased risk of cardiovascular events and complications. In recent years new data have been collected on this issue, strengthening the clinical relevance of elevated heart rate as a specific hypertensive phenotype. The present paper will review old and new data on the prognostic importance of resting tachycardia in the hypertensive patient. It will also examine the role of the sympathetic nervous system in the development of this alteration as well as its therapeutic implications. The different approaches to dynamically assess heart rate values in the clinical setting will be finally discussed.

Why is Intradialytic Hypotension the Commonest Complication of Outpatient Dialysis Treatments?

Intradialytic hypotension (IDH) is the most frequent complication of hemodialysis (HD) treatments with a frequency of 10% to 12% for patients with chronic kidney disease attending for outpatient treatments and is associated with both temporary ischemic stress to vital organs, including the heart and brain, and increased patient mortality. Although there have been many different definitions of IDH over the years, an absolute nadir systolic blood pressure (SBP) has the strongest association with patient outcomes. The unifying pathophysiology is one of reduced effective blood volume, resulting in lower plasma tonicity, and if this cannot be adequately compensated for by activation of neurohumeral systems, then arteriolar tone and blood pressure fall. The risk factors for developing IDH are numerous, ranging from patient-related factors, including age and comorbidity with reduced cardiac reserve, to patient compliance with dietary and lifestyle advice, to reactions with the extracorporeal circuit and medications, choice of dialysate composition and temperature, setting of postdialysis target weight, ultrafiltration rate, and profiling. Advances in dialysis machine technology by providing real time estimates of the effective circulating volume and adjusting dialysate composition to maintain vascular tonicity are being developed, but currently require more sophisticated biofeedback loops to be clinically effective in preventing IDH. While awaiting advances in artificial intelligence, the clinician continues to rely on patient education to limit interdialytic weight gains, frequent assessment of the postdialysis target weight, adjusting dialysate composition and temperature, introducing convective therapies to increase thermal losses, and altering dialysis session duration and frequency to reduce ultrafiltration rate requirements.

Association between the risk of heart failure hospitalization and end-stage renal disease with digoxin usage in patients with cardiorenal syndrome: A population-based study

Background

The management of the coexistence of heart disease and kidney disease is increasingly challenging for clinicians. Chronic kidney disease (CKD) is not only a prevalent comorbidity of patients with heart failure but has also been identified as a noteworthy risk factor for all-cause mortality and poor clinical outcomes. Digoxin is one of the commonest treatments for heart disease. There are few trials investigating the role of digoxin in patients with cardiorenal syndrome (CRS). This study aims to examine the association between digoxin usage and clinical outcomes in patients with CRS in a nationwide cohort.

Method

We conducted a population-based study that included 705 digoxin users with CRS; each patient was age, sex, comorbidities, and medications matched with three non-users who were randomly selected from the CRS population. Cox proportional hazards regression analysis was conducted to estimate the effects of digoxin on the incidence of all-cause mortality, congestive heart failure (CHF) hospitalization, coronary artery disease (CAD) hospitalization, and end-stage renal disease (ESRD).

Results

The all-cause mortality rate was significantly higher in digoxin users than in non-users (adjusted hazard ratio [aHR] = 1.26; 95% confidence interval [CI] = 1.09-1.46, p = 0.002). In a subgroup analysis, there was significantly high mortality in the 0.26-0.75 defined daily dose (DDD) subgroup of digoxin users (aHR = 1.49; 95% CI = 1.23-1.82, p<0.001). Thus, the p for trend was 0.013. With digoxin prescription, the CHF hospitalization was significantly higher [subdistribution HR (sHR) = 1.17; 95% CI = 1.05-1.30, p = 0.004], especially in the >0.75 DDD subgroup (sHR = 1.19; 95% CI = 1.01-1.41, p = 0.046; p for trend = 0.006). The digoxin usage lowered the coronary artery disease (CAD) hospitalization in the > 0.75 DDD subgroup (sHR = 0.79; 95% CI = 0.63-0.99, p = 0.048). In renal function progression, more patients with CRS entered ESRD with digoxin usage (sHR = 1.34; 95% CI = 1.16-1.54, p<0.001). There was a significantly greater incidence of ESRD in the < 0.26 DDD and 0.26-0.75 DDD subgroups of digoxin users (sHR = 1.32; 95% CI = 1.06-1.66, p = 0.015; sHR = 1.44; 95% CI = 1.18-1.75; p for trend<0.001).

Conclusion

Digoxin should be prescribed with caution to patients with CRS.

Heart rate thresholds for cardiovascular risk and sympathetic activation in the metabolic syndrome

AIMS

We examined whether to what extent resting heart rate (HR) values are capable to reflect in the metabolic syndrome (MS) a different degree of sympathetic activation. We also thought to determine at which HR cutoff values the sympathetic nervous system becomes more activated in the MS.

METHODS

In 70 MS patients aged 55.5 ± 1.8 (mean ± SEM) years we evaluated muscle sympathetic nerve traffic (MSNA, microneurography) and venous plasma norepinephrine (NE, HPLC assay), subdividing the study population in three different subgroups according to resting clinic and 24-h HR values (< 70, 70-79 and ≥ 80 beats/min).

RESULTS

MS patients with clinic HR values ≥ 80 beats/min displayed MSNA and NE values significantly increased when compared to those found in MS with HR between 70 and 79 beats/min or below 70 beats/min (MSNA: 55.2 ± 0.9 vs 44.6 ± 0.6 and 39.2 ± 0.6 bursts/min, P < 0.01, NE: 403.9 ± 6.9 vs 330.1 ± 4.3 and 258.3 ± 6.8 pg/ml, respectively, P < 0.01). A similar behavior was observed for 24-h HR. In the group as a whole both MSNA and plasma NE showed highly significant direct relationships with clinic HR, the correlation being similar for MSNA and NE (r = 0.89 and r = 0.91, P < 0.01 for both) Similar significant relationships were also found between 24-h HR values and MSNA or NE.

CONCLUSIONS

In the MS HR values ≥ 80 beats/min are associated with an increased sympathetic activation, both when assessed by direct recording of MSNA and when evaluated as plasma NE. The sympathetic overdrive parallels for magnitude the HR elevations, this being the case for both clinic and 24-h HR.

Elevated heart rate as sympathetic biomarker in human obesity

BACKGROUND AND AIM

The present study was aimed at determining whether and to what extent a specific heart rate (HR) cutoff value allows to identify in obeses a more pronounced level of adrenergic overdrive.

METHODS AND RESULTS

In 86 obese subjects aged 44.7 ± 0.9 (mean ± SEM) years and in 45 heathy lean controls of similar age we evaluated muscle sympathetic nerve traffic (MSNA, microneurography) and venous plasma norepinephrine (NE, HPLC assay), subdividing the subjects in 3 different groups according to their resting clinic and 24-h HR values (<70, 70-79 and 80-89 beats/minute). MSNA and plasma NE values detected in the three obese groups were almost superimposable each other, no significant difference between groups being observed. A similar behavior was observed when HR values were assessed during the 24-h Holter monitoring. In the group as a whole no significant relationship was detected between MSNA, plasma NE and clinic HR, this being the case also when 24-h HR replaced clinic HR in the correlation analysis. In contrast lean controls displayed a progressive significant increase in MSNA values form the group with clinic (and 24 Holter) values below 70 beats/minute to the ones with HR values between 70 and 79 and above 80 beats/minute.

CONCLUSIONS

In the obese state measurement of resting HR may allow to provide some general information on the functional status of the adrenergic cardiovascular drive. When the information required, however, are more subtle the sensitivity of the approach appears to be reduced and HR cannot be regarded as a faithful sympathetic biomarker.