The relationship between changes in peritoneal membrane solute transfer characteristics and cardiac remodeling in patients with peritoneal dialysis

INTRODUCTION

We aimed to determine the relationship between the dilatation of the heart chambers and the change in peritoneal membrane solute transfer characteristics (PMTC) in long-term peritoneal dialysis (PD) patients.

METHODS

This is a retrospective, single-center study including the follow-up of maintenance PD patients. According to the changes in PMTC from baseline to the last visit, patients were divided into three groups; stable (n = 11), increased (n = 41), and decreased transporters (n = 35).

RESULTS

Left atrium (LA) and Right ventricle (RV) dilatation were more prominent in the PMTC-decreased group compared to PMTC-increased and stable groups (p < 0.001 and p = 0.07, respectively). The Cox regression analysis showed that only decreased PMTC was associated with LA dilatation (HR 2.89 [CI 95%1.54, 5.45] p < 0.01) and RV dilatation (HR 3.01 [CI 95%1.40, 6.21] p < 0.01).

CONCLUSION

PD can be associated with unfavorable dynamic changes in cardiac structure and functions even at the subclinical level.

Association of arteriovenous fistulae with precapillary pulmonary hypertension - A single center retrospective analysis of invasive hemodynamic parameters

BACKGROUND

Pulmonary hypertension (pH) is a well-known complication among patients with chronic kidney disease (CKD). Arteriovenous fistulae (AVF) have been associated with pH mainly by increasing cardiac output. However, the burden of precapillary pH in individuals with CKD and an AVF is unclear.

OBJECTIVES

To better and more fully understand the mechanism and development of precapillary pH in patients with AVF, as well as the consequences of precapillary pH in these patients.

METHODS

This was a large retrospective study of patients with CKD stage 4 or 5 who underwent right heart catheterization (RHC) from 2018 to 2023. The data were stratified according to the presence of AVF. To determine if AVF was independently associated with precapillary pH, we used a multivariable logistic regression analysis adjusting for demographics and potential comorbidities associated with precapillary pH, including diagnosis of chronic lung disease, obstructive sleep apnea, connective tissue disease, history of venous thromboembolism, chronic anemia, and heart failure.

RESULTS

Of 651 patients with CKD4 or CKD5, 145 (22 %) had AVF and 506 (78 %) did not have AVF. Within the AVF group, the median age was 64 years (IQR 54-71), and they were predominantly males (61 %, n = 88) and African American (77 %, n = 111). A total of 31 % (n = 45) had evidence of precapillary pH, 30 % (n = 43) of combined pH, and 14 % (n = 20) of isolated postcapillary pH. Compared to the non-AVF group, precapillary pH was more likely in the AVF group (31% vs 17 %, p < 0.0001). On multivariable analysis, AVF was independently associated with precapillary pH (OR 2.47, CI 1.56-3.89; p < 0.0001). The median time from dialysis initiation to RHC date (and precapillary pH diagnosis) was 6 years (IQR 3-8).

CONCLUSION

Based on RHC findings, almost one-third of patients with CKD and AVF had precapillary pH. The presence of AVF was independently associated with precapillary pH.

Pulmonary hypertension and chronic kidney disease: prevalence, pathophysiology and outcomes

Pulmonary hypertension (PH) is common in patients with chronic kidney disease (CKD) or kidney failure, with an estimated prevalence of up to 78% in those referred for right-heart catheterization. PH is independently associated with adverse outcomes in CKD, raising the possibility that early detection and appropriate management of PH might improve outcomes in at-risk patients. Among patients with PH, the prevalence of CKD stages 3 and 4 is estimated to be as high as 36%, and CKD is also independently associated with adverse outcomes. However, the complex, heterogenous pathophysiology and clinical profile of CKD-PH requires further characterization. CKD is often associated with elevated left ventricular filling pressure and volume overload, which presumably leads to pulmonary vascular stiffening and post-capillary PH. By contrast, a distinct subgroup of patients at high risk is characterized by elevated pulmonary vascular resistance and right ventricular dysfunction in the absence of pulmonary venous hypertension, which may represent a right-sided cardiorenal syndrome defined in principle by hypervolaemia, salt avidity, low cardiac output and normal left ventricular function. Current understanding of CKD-PH is limited, despite its potentially important ramifications for clinical decision making. In particular, whether PH should be considered when determining the suitability and timing of kidney replacement therapy or kidney transplantation is unclear. More research is urgently needed to address these knowledge gaps and improve the outcomes of patients with or at risk of CKD-PH.

Kidney Replacement Therapies in Advanced Heart Failure - Timing, Modalities, and Clinical Considerations

Acute kidney dysfunction is commonly encountered in advanced heart failure and carries significant prognostic implications, often leading to poorer outcomes and increased mortality. It can alter the course of decision making for left ventricular assist device (LVAD) and cardiac transplantation candidacy. Kidney replacement therapies (KRT) offer a critical intervention in this context but require careful consideration of timing, various types of KRT modalities, individual patient preferences and circumstances. This review discusses the intricacies of KRT in advanced heart failure, examining how to optimize timing and choose among the various KRT modalities. It also provides a detailed discussion on the unique clinical scenarios that clinicians may face when treating this vulnerable patient group.

Clinical Update in Heart Failure with Preserved Ejection Fraction

PURPOSE OF REVIEW

To review the most recent clinical trials and data regarding epidemiology, pathophysiology, diagnosis, and treatment of heart failure with preserved ejection fraction with an emphasis on the recent trends in cardiometabolic interventions.

RECENT FINDINGS

Heart failure with preserved ejection fraction makes up approximately half of overall heart failure and is associated with significant morbidity, mortality, and overall burden on the healthcare system. It is a complex, heterogenous syndrome and clinical trials, to this point, have not revealed quite as many effective treatment options when compared to heart failure with reduced ejection fraction. Nevertheless, there is an expanding amount of data insight into the pathogenesis of this disease and the potential for newer therapies and management strategies. Heart failure with preserved ejection fraction pathology has been found to be linked to abnormal energetics, myocyte hypertrophy, cell signaling, inflammation, ischemia, and fibrosis. These mechanisms also intricately overlap with the significant comorbidities often associated with heart failure with preserved ejection fraction including, but not limited to, atrial fibrillation, chronic kidney disease, hypertension, obesity and coronary artery disease. Treatment of this disease, therefore, should focus on the management and strict regulation of these comorbidities by pharmacologic and nonpharmacologic means. In this review, a clinical update is provided reviewing the most recent clinical trials and data regarding epidemiology, pathophysiology, diagnosis, and treatment of heart failure with preserved ejection fraction with an emphasis on the recent trend in cardiometabolic interventions.

Therapeutic approaches for pulmonary hypertension in patients with chronic kidney disease

PURPOSE OF REVIEW

Pulmonary hypertension is a common comorbidity in patients with chronic kidney disease (CKD), but therapeutic options are limited. We discuss the epidemiology of pulmonary hypertension in patients with CKD and review therapies for pulmonary hypertension with a focus on emerging treatments for pulmonary arterial hypertension (PAH).

RECENT FINDINGS

The definition of pulmonary hypertension has been updated to a lower threshold of mean pulmonary artery pressures of more than 20 mmHg, potentially leading to more patients with CKD to qualify for the diagnosis of pulmonary hypertension. Endothelin receptor antagonists, a class of medications, which demonstrated efficacy in patients with PAH, have been shown to slow progression of CKD, but their efficacy in lowering pulmonary artery pressures and their effects on reducing cardiovascular mortality in this population remains unproven. Sotatercept, a novel activin signaling inhibitor, which was previously studied in dialysis patients has been shown to increase exercise capacity in patients with PAH. These studies may lead to new specific therapies for pulmonary hypertension in patients with CKD.

SUMMARY

Pulmonary hypertension is common in patients with CKD. Although our understanding of factors leading to pulmonary hypertension in this population have evolved, evidence supporting disease-specific therapy in CKD is limited arguing for larger, long-term studies.

A Huge High-Flow Aneurysmal Renal Arteriovenous Malformation Treated With Endovascular Transcatheter Embolization

Renal arteriovenous anomalies are uncommon. They are characterized by an abnormal vascular connection that usually bypasses the capillary bed. Most are acquired arteriovenous fistulas (AVF) while the rest are congenital or idiopathic arteriovenous malformations (AVM). AVF are usually caused by renal interventions, trauma, or neoplastic processes. They can lead to hypertension, heart failure, hematuria, and renal insufficiency. A 69-year-old woman presented with arrhythmia, tachycardia, mild ankle edema, and increasing fatigue. Right kidney color Doppler ultrasound confirmed the presence of a huge AVM with a blood flow of 9 L/minute and a dilated, 35 mm in diameter, right renal vein. Two months later, an attempt to embolize the AVM failed as the Amplatzer™ Vascular Plug II (Abbott Laboratories, Chicago, Illinois, United States) migrated to the pulmonary circulation and was later removed. Complete embolization was achieved by implanting two Amplatzer Vascular Plug IIs, various embolization coils, histoacryl glue, and lipiodol. Control angiography revealed significant stenosis in the right subclavian artery endovascular access, which was managed with BeGraft (Bentley InnoMed GmbH, Hechingen, Germany) and Zilver (Cook Group Incorporated, Bloomington, Indiana, United States) stents. The patient was discharged on the third postoperative day, all her symptoms resolved, and she reported eventual recovery. Three months later, the patient was operated on due to a 40x58 mm pseudoaneurysm at the right femoral access site. Thus, renal AVMs should be included as a potential alternative diagnosis for various symptoms such as hematuria and hypertension resistant to medication. Endovascular embolization is a less-invasive, safer, and more effective option than open surgery but has a risk of complications. Success requires fully occluding the shunted vessel, preventing embolic material migration, and preserving normal arterial branches. It depends on selecting adequate techniques and embolic materials individually, based on etiology and precise vascular anatomy assessment.

Practical Guidance for Hemodynamic Assessment by Right Heart Catheterization in Management of Heart Failure

Heart failure is a clinical syndrome characterized by the inability of the heart to meet the circulatory demands of the body without requiring an increase in intracardiac pressures at rest or with exertion. Hemodynamic parameters can be measured via right heart catheterization, which has an integral role in the full spectrum of heart failure: from ambulatory patients to those in cardiogenic shock, as well as patients being considered for left ventricular device therapy and heart transplantation. Hemodynamic data are critical for prompt recognition of clinical deterioration, assessment of prognosis, and guidance of treatment decisions. This review is a field guide for hemodynamic assessment, troubleshooting, and interpretation for clinicians treating patients with heart failure.

Arteriovenous fistula for haemodialysis as a predictor of de novo heart failure in kidney transplant recipients

Background

The haemodynamic effects of a functioning haemodialysis arteriovenous fistula (AVF) can cause or exacerbate heart failure (HF). We investigated whether the presence of an AVF at the time of kidney transplant (KT) is associated with de novo HF.

Methods

This was an observational cohort study including adult patients who received a KT in the West of Scotland between 2010 and 2020. We evaluated the risk and associations of pretransplant factors with de novo HF, alone and as a composite cardiovascular (CV) outcome (including non-fatal myocardial infarction, non-fatal stroke, de novo HF and CV death). Multivariable proportional hazards regression and sensitivity analyses were used to identify independent correlates of the outcomes.

Results

Among 1330 included patients, the incident rate of de novo HF after transplantation was 58/1000 person-years [95% confidence interval (CI) 50-67] in AVF patients (n = 716) compared with 33/1000 person-years (95% CI 27-41) in non-AVF patients (n = 614). De novo HF was associated with the presence of an AVF [adjusted hazard ratio (aHR) 2.14 (95% CI 1.40-3.26)], duration of dialysis [aHR 1.03/year increase (95% CI 1.01-1.04)], age at transplant [aHR 1.03/year increase (95% CI 1.02-1.05)], female sex [aHR 1.93 (95% CI 1.40-2.65)] and pretransplant diabetes [aHR 2.43 (95% CI 1.48-4.01)]. The presence of an AVF was also associated with the composite CV outcome [aHR 1.91 (95% CI 1.31-2.78)].

Conclusions

The presence of an AVF may be an underrecognized modifiable predictor of de novo HF posttransplantation.

New-onset atrial fibrillation following arteriovenous fistula increases adverse clinical events in dialysis patients with end-stage renal disease

Background

End-stage renal disease (ESRD) patients have a high potential cardiovascular burden, and cardiovascular disease (CVD) is the leading cause of death in maintenance haemodialysis (MHD) patients. Arteriovenous fistula (AVF) is the preferred vascular access for MHD patients, but AVF significantly affects the haemodynamics of the cardiovascular system, leading to or exacerbating CVD, including atrial fibrillation (AF). This study aimed to evaluate the impact of AVF on cardiac function, especially of the left atrium (LA), in patients with ESRD and to further explore the relationship between AVF establishment and the occurrence of AF.

Methods

We selected 1,107 ESRD patients on haemodialysis using AVF and 550 patients with tunneled-cuffed catheters (TCC) admitted between January 2016 and December 2022 for follow-up to compare the rate of AF between the two groups. A total of 153 patients in the AVF group with complete information (clinical data, echocardiographic and biochemical indices, and other data) were enrolled and retrospectively analysed for risk factors for the development of AF and were followed up for adverse clinical outcomes (including all-cause death, cardiac death, readmission due to heart failure, and stroke).

Results

The incidence of new-onset AF was higher in the AVF group than the TCC group after dialysis access was established (16.30% vs. 5.08%, P < 0.001). Echocardiography showed that the LA anteroposterior diameter increased (P < 0.001) and the incidence of AF increased from 11.76% to 26.14% (P = 0.001) after AVF establishment. Multivariate logistic regression analysis showed that age and LA enlargement were independent risk factors for new-onset AF after AVF establishment (P < 0.05). Adverse clinical outcomes were more common in patients with AF than in patients without AF (P < 0.001). Multivariate Cox risk regression analysis suggested that new-onset AF (HR = 4.08, 95% CI: 2.00-8.34, P < 0.001) and left ventricular systolic dysfunction (HR = 2.42, 95% CI: 1.20-4.88, P = 0.01) after AVF establishment were independent risk factors for adverse clinical outcomes.

Conclusion

LA enlargement after AVF establishment is associated with a significant increase in the incidence of AF, in addition, AF which is as an important influential factor in patients with MHD combined other systemic diseases might increase adverse clinical events.

Clinical Trial Registration

(NCT06199609).

Hemodialysis Patients with High-Flow Arteriovenous Fistulas: An Evaluation of the Impact on Cardiac Function

Purpose

: Patients undergoing hemodialysis often experience changes in cardiac function when they have a high-flow arteriovenous fistula (AVF). This study aimed to assess the effect of high-flow AVFs on cardiac function in patients undergoing hemodialysis.

Materials and Methods

: A longitudinal study was conducted on hemodialysis patients with high-flow AVFs. Echocardiographic parameters, such as left ventricular ejection fraction (LVEF), left atrial diameter (LAD), left ventricular end-diastolic dimension (LVEDD), right ventricular end-diastolic dimension (RVEDD), inferior vena cava diameter (IVCD), systolic blood pressure, and diastolic blood pressure, were measured and compared before and after AVF creation.

Results

: One hundred hemodialysis patients with high-flow AVFs (mean age: 55.95±13.39 years, mean body mass index: 24.71±3.43 kg/m²) were studied. LVEF significantly decreased (51.10%±5.39% to 47.50%±5.79%), while LAD, LVEDD, and IVCD significantly increased after AVF creation (P<0.05). Systolic (132.49±16.42 mmHg to 146.60±17.43 mmHg) and diastolic (79.98±8.40 mmHg to 83.33±9.68 mmHg) blood pressure substantially rose post-fistularization (P<0.001). Notably, LVEF reduction was more significant in brachio-cephalic AVFs (46.29%±4.24%) compared to distal radio-cephalic or snuffbox AVFs (49.17%±7.15%) (P=0.014).

Conclusion

: High-flow AVFs can significantly affect echocardiographic parameters in hemodialysis patients, thereby increasing the risk of cardiac failure. Close cardiac monitoring may be necessary for early intervention. Distal AVFs may be preferable in patients with decreased cardiac function.

Systemic vascular resistance predicts high-output cardiac failure in patients with high-flow arteriovenous fistula

AIMS

Patients with high-flow arteriovenous (AV) access are at risk of developing high-output cardiac failure (HOCF) and subsequent hospitalization. However, diagnosing HOCF is challenging and often requires invasive procedures. The role of systemic vascular resistance (SVR) in diagnosing HOCF is underestimated, and its predictive value is limited. Our study aims to identify non-invasive risk factors for HOCF to facilitate early diagnosis and timely surgical interventions.

METHODS AND RESULTS

We included 109 patients with high-flow AV access who underwent serial echocardiography. The retrospective cohort was divided into two groups based on their hospitalization due to HOCF. The two groups were matched for age and gender. After a mean follow-up of 25.1 months, 19 patients (17.4%) were hospitalized due to HOCF. The two groups had similar baseline characteristics. However, the HOCF group had a higher value of vascular access blood flow (Qa) (2168 ± 856 vs. 1828 ± 617 mL/min; P = 0.045). Echocardiographic analysis revealed that the HOCF group had more pronounced left ventricular diastolic dysfunction (E/e': 21.1 ± 7.3 vs. 16.2 ± 5.9; P = 0.002), more severe pulmonary hypertension (right ventricular systolic pressure: 41.4 ± 16.7 vs. 32.2 ± 12.8; P = 0.009), a higher Doppler-derived cardiac index (CI) (4.3 ± 0.8 vs. 3.7 ± 1.1; P = 0.031), and a lower Doppler-derived estimated SVR (eSVR) value (5.5 ± 0.3 vs. 6.9 ± 0.2; P = 0.002) than the non-HOCF group. Using multivariable Cox regression analysis, a low eSVR value (<6) emerged as an independent predictor of HOCF hospitalization with a hazard ratio of 9.084 (95% confidence interval, 2.33-35.39; P = 0.001). Receiver operating characteristic curve analysis indicated that CI/eSVR values more accurately predicted HOCF hospitalization [sensitivity: 94.7%, specificity: 51.0%, area under the curve (AUC): 0.75, P < 0.001] than the Qa/cardiac output ratio (AUC: 0.50, P = 0.955), Qa values ≥ 2000 mL/min (AUC: 0.60, P = 0.181), and Qa values indexed for height in metres (AUC: 0.65, P = 0.040).

CONCLUSIONS

In patients with high-flow AV access, low eSVR values obtained through non-invasive Doppler echocardiography were associated with a high rate of HOCF hospitalizations. Therefore, routine eSVR screening in these patients might expedite the diagnosis of HOCF.

CZecking heart failure in patients with advanced chronic kidney disease (Czech HF-CKD): Study protocol

BACKGROUND

Heart failure (HF) is a frequent cause of morbidity and mortality of end-stage kidney disease (ESKD) patients on hemodialysis. It is not easy to distinguish HF from water overload. The traditional HF definition has low sensitivity and specificity in this population. Moreover, many patients on hemodialysis have exercise limitations unrelated to HF. Therefore, we postulated two new HF definitions ((1) Modified definition of the Acute Dialysis Quality Improvement working group; (2) Hemodynamic definition based on the calculation of the effective cardiac output). We hypothesize that the newer definitions will better identify patients with higher number of endpoints and with more advanced structural heart disease.

METHODS

Cohort, observational, longitudinal study with recording predefined endpoints. Patients (n = 300) treated by hemodialysis in six collaborating centers will be examined centrally in a tertiary cardiovascular center every 6-12 months lifelong or till kidney transplantation by detailed expert echocardiography with the calculation of cardiac output, arteriovenous dialysis fistula flow volume calculation, bio-impedance, and basic laboratory analysis including NTproBNP. Effective cardiac output will be measured as the difference between measured total cardiac output and arteriovenous fistula flow volume and systemic vascular resistance will be also assessed non-invasively. In case of water overload during examination, dry weight adjustment will be recommended, and the patient invited for another examination within 6 weeks. A composite major endpoint will consist of (1) Cardiovascular death; (2) HF worsening/new diagnosis of; (3) Non-fatal myocardial infarction or stroke. The two newer HF definitions will be compared with the traditional one in terms of time to major endpoint analysis.

DISCUSSION

This trial will differ from others by: (1) detailed repeated hemodynamic assessment including arteriovenous access flow and (2) by careful assessment of adequate hydration to avoid confusion between HF and water overload.

Interatrial Shunt Devices

Elevated left atrial pressure during exercise is a hallmark of heart failure (HF) and is associated with adverse left atrial remodeling and poor outcomes. To decompress the pressure-overloaded left atrium in patients with HF, several device-based approaches have been developed to create a permanent, pressure-dependent, left-to-right interatrial shunt. Such approaches are currently in various stages of investigations in both HF with reduced ejection fraction (EF) and HF with preserved EF. This review discusses the evolution of the concept of left atrial decompression and summarizes the current landscape of device-based approaches used for left atrial decompression.

Novel Therapeutic Approaches in the Management of Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive and incurable disease that impairs kidney function. Its prevalence is estimated to affect up to 800 million individuals within the general population, and patients with diabetes and hypertension are particularly at risk. This disorder disrupts the physiological mechanisms of the body, including water and electrolyte balance, blood pressure regulation, the excretion of toxins, and vitamin D metabolism. Consequently, patients are exposed to risks such as hyperkalemia, hyperphosphatemia, metabolic acidosis, and blood pressure abnormalities. These risks can be reduced by implementing appropriate diagnostic methods, followed by non-pharmacological (such as physical activity, dietary, and lifestyle adjustment) and pharmacological strategies after diagnosis. Selecting the appropriate diet and suitable pharmacological treatment is imperative in maintaining kidney function as long as possible. Drugs such as finerenone, canakinumab, and pentoxifylline hold promise for improved outcomes among CKD patients. When these interventions prove insufficient, renal replacement therapy becomes essential. This is particularly critical in preserving residual renal function while awaiting renal transplantation or for patients deemed ineligible for such a procedure. The aim of this study is to present the current state of knowledge and recent advances, providing novel insights into the treatment of chronic kidney disease.

Pathophysiological concepts and screening of cardiovascular disease in dialysis patients

Dialysis patients experience 10-20 times higher cardiovascular mortality than the general population. The high burden of both conventional and nontraditional risk factors attributable to loss of renal function can explain higher rates of cardiovascular disease (CVD) morbidity and death among dialysis patients. As renal function declines, uremic toxins accumulate in the blood and disrupt cell function, causing cardiovascular damage. Hemodialysis patients have many cardiovascular complications, including sudden cardiac death. Peritoneal dialysis puts dialysis patients with end-stage renal disease at increased risk of CVD complications and emergency hospitalization. The current standard of care in this population is based on observational data, which has a high potential for bias due to the paucity of dedicated randomized clinical trials. Furthermore, guidelines lack specific guidelines for these patients, often inferring them from non-dialysis patient trials. A crucial step in the prevention and treatment of CVD would be to gain better knowledge of the influence of these predisposing risk factors. This review highlights the current evidence regarding the influence of advanced chronic disease on the cardiovascular system in patients undergoing renal dialysis.

Clinical Outcomes in Patients on Hemodialysis with Congestive Heart Failure

Introduction

Congestive heart failure (CHF) is one of the common complications in patients with end-stage kidney disease. In the general population, CHF increases the risk of the death. However, there is no well-designed relevant study in the Chinese hemodialysis (HD) population addressing the risks associated with CHF. The aim of this study was to explore the impact of CHF on clinical outcomes in HD patients.

Methods

Data from a prospective cohort study, the China Dialysis Outcomes and Practice Patterns Study (DOPPS) 5 (2012-2015), were analyzed. Demographic data, comorbidities, lab data, and death records were extracted. CHF was defined by the diagnosis records upon study inclusion. Our primary outcome was all-cause and cardiovascular (CV) mortality; secondary outcomes were all-cause and cause-specific hospitalization risk. Associations between CHF and outcomes were evaluated using Cox regression models. Stepwise multivariate logistic regression was used to identify the related risk factors, and subgroup analyses were carried out.

Results

Of 1,411 patients without missing CHF history information, 24.1% (340) had CHF diagnosis at enrollment. The overall mortality rates were 21.8% versus 12.0% (p < 0.001) in patients with and without CHF during follow-up, respectively. CHF was associated with higher all-cause mortality (adjusted HR: 1.72, 95% confidence interval [CI]: 1.17-2.53, p = 0.006), and the association with CV death was of similar magnitude (HR: 1.60, 95% CI: 0.91-2.81, p = 0.105). CHF patients had more episodes of hospitalization due to heart failure (HR: 2.93, 95% CI: 1.49-5.76, p < 0.01). However, compared with patients without CHF, the all-cause hospitalization risk was not much higher in CHF patients (HR: 1.09, 95% CI: 0.90-1.33, p = 0.39). Subgroup analysis found that the effect of CHF on all-cause mortality was stronger for male patients, patients with residual renal function, the elderly (≥60 years of age), patients with arteriovenous fistulae vascular accesses, nondiabetic patients, low-flux dialyzer users, and inadequately dialyzed patients (standardized Kt/V <2).

Conclusion

In HD patients, CHF was found to be associated with a higher risk of all-cause mortality and cause-specific hospitalization risk. Further research is needed to identify opportunities to improve care for HD patients combined with CHF.

Characterizing Heart Failure With Preserved Ejection Fraction in End-Stage Liver Disease and Liver Transplant Outcomes

Background

Heart failure with preserved ejection fraction (HFpEF) and its risk factors are increasingly recognized in patients with end-stage liver disease (ESLD).

Objectives

The aim of this study was to characterize HFpEF and identify relevant risk factors in patients with ESLD. Additionally, the prognostic impact of high-probability HFpEF on post-liver transplantation (LT) mortality was investigated.

Methods

Patients with ESLD prospectively enrolled from the Asan LT Registry between 2008 and 2019 were divided into groups with low (scores of 0 and 1), intermediate (scores of 2-4), and high (scores of 5 and 6) probability using the Heart Failure Association-PEFF diagnostic score for HFpEF. Gradient-boosted modeling in machine learning was further used to appraise the apparent importance of risk factors. Finally, post-LT all-cause mortality was followed for 12.8 years (median 5.3 years); there were 498 deaths after LT.

Results

Among the 3,244 patients, 215 belonged to the high-probability group, commonly those with advanced age, female sex, anemia, dyslipidemia, renal dysfunction, and hypertension. The highest risk factors for the high-probability group, according to gradient-boosted modeling, were female sex, anemia, hypertension, dyslipidemia, and age >65 years. Among patients with Model for End-Stage Liver Disease scores of >30, those with high, intermediate, and low probability had cumulative overall survival rates of 71.6%, 82.2%, and 88.9% at 1 year and 54.8%, 72.1%, and 88.9% at 12 years after LT (log-rank P = 0.026), respectively.

Conclusions

High-probability HFpEF was found in 6.6% of patients with ESLD with poorer long-term post-LT survival, especially those with advanced stages of liver disease. Therefore, identifying HFpEF using the Heart Failure Association-PEFF score and addressing modifiable risk factors can improve post-LT survival.

Chronic Kidney Disease as a Comorbidity in Heart Failure

Heart failure (HF) is one of the greatest problems in healthcare and it often coexists with declining renal function. The pathophysiology between the heart and the kidneys is bidirectional. Common mechanisms leading to the dysfunction of these organs result in a vicious cycle of cardiorenal deterioration. It is also associated with difficulties in the treatment of aggravating HF and chronic kidney disease (CKD) and, as a consequence, recurrent hospitalizations and death. As the worsening of renal function has an undeniably negative impact on the outcomes in patients with HF, searching for new treatment strategies and identification of biomarkers is necessary. This review is focused on the pathomechanisms in chronic kidney disease in patients with HF and therapeutic strategies for co-existing CKD and HF.

Cardiac changes following arteriovenous fistula creation in a mouse model

BACKGROUND

Arteriovenous fistula (AVF) creation may negatively affect cardiac structure and function and impact cardiovascular mortality. The objective of this study was to develop and characterize the cardiac changes following AVF creation in a murine AVF model.

METHODS

AVFs were constructed using the carotid artery and jugular vein in C57BL/6 mice. Sham-operated AVF mice served as the control group. 2D-echocardiography was performed prior to AVF creation (baseline) and at 7 and 21 days after creation in AVF and sham-operated mice. Picrosirius red was used to stain the left ventricle for collagen production.

RESULTS

The cardiac output (CO), left ventricular end diastolic (LVEDD) and systolic (LVESD) diameter, and end-diastolic (LVEDV) and systolic (LVESV) volume was significantly increased at 7 and 21 days in AVF compared to sham-operated mice. There was also a significant increase in CO, LVEDD, LVESD, LVEDV, and LVESV from baseline to 21 days within the AVF group, but not the sham-operated mice. There was a significant decrease in ejection fraction and fractional shortening at 21 days in AVF compared to sham-operated mice. Picrosirius red was significantly more prominent around both the perivascular and interstitial areas of the cardiac tissue from AVF mice compared to sham-operated AVF mice at 21 days.

CONCLUSIONS

The creation of an AVF in our murine model leads to cardiac changes such as increased cardiac output, left ventricular dilation, and cardiac fibrosis, while showing reductions of ejection fraction and fractional shortening.

Managing Heart Failure in Patients on Dialysis: State-of-the-Art Review

Heart failure (HF) and end-stage kidney disease (ESKD) frequently coexist; 1 comorbidity worsens the prognosis of the other. HF is responsible for almost half the deaths of patients on dialysis. Despite patients' with ESKD composing an extremely high-risk population, they have been largely excluded from landmark clinical trials of HF, and there is, thus, a paucity of data regarding the management of HF in patients on dialysis, and most of the available evidence is observational. Likewise, in clinical practice, guideline-directed medical therapy for HF is often down-titrated or discontinued in patients with ESKD who are undergoing dialysis; this is due to concerns about safety and tolerability. In this state-of-the-art review, we discuss the available evidence for each of the foundational HF therapies in ESKD, review current challenges and barriers to managing patients with HF on dialysis, and outline future directions to optimize the management of HF in these high-risk patients.

Hypertension and cardiomyopathy associated with chronic kidney disease: epidemiology, pathogenesis and treatment considerations

Chronic kidney disease (CKD) is a complex condition with a prevalence of 10-15% worldwide. An inverse-graded relationship exists between cardiovascular events and mortality with kidney function which is independent of age, sex, and other risk factors. The proportion of deaths due to heart failure and sudden cardiac death increase with progression of chronic kidney disease with relatively fewer deaths from atheromatous, vasculo-occlusive processes. This phenomenon can largely be explained by the increased prevalence of CKD-associated cardiomyopathy with worsening kidney function. The key features of CKD-associated cardiomyopathy are increased left ventricular mass and left ventricular hypertrophy, diastolic and systolic left ventricular dysfunction, and profound cardiac fibrosis on histology. While these features have predominantly been described in patients with advanced kidney disease on dialysis treatment, patients with only mild to moderate renal impairment already exhibit structural and functional changes consistent with CKD-associated cardiomyopathy. In this review we discuss the key drivers of CKD-associated cardiomyopathy and the key role of hypertension in its pathogenesis. We also evaluate existing, as well as developing therapies in the treatment of CKD-associated cardiomyopathy.

Novel external stenting for reconstruction of high flow arteriovenous fistula

BACKGROUND

High-flow arteriovenous fistulae (HF-AVF) may lead to adverse cardiac remodeling in hemodialysis patients. We have investigated whether a novel external stent is safe and effective in reducing and stabilizing flow rates during a 1-year follow-up after HF-AVF reconstruction.

METHODS

All patients with HF-AVF (access flow rate ⩾ 1500 ml/min), who underwent HF-AVF reconstruction with external stenting in two centers between June 2018 and May 2020, were included in this retrospective analysis. During HF-AVF reconstruction, the dilated vein segment was resected, underwent volume reduction, and was externally stabilized using a braided cobalt-chromium external stent. AVF flow rates were assessed preoperatively, intraoperatively, and at follow up visits using duplex ultrasound.

RESULTS

Forty-three HF-AVFs in 42 patients were reconstructed and supported with an external stent (mean age 49 years, range 20-86 years; 74% men). Fifty-one percent were forearm AVFs, 49% were upper arm. The mean preoperative flow rate was 2622 ± 893 ml/min (range: 1500-6000 ml/min) and was decreased to 710 ± 221 ml/min (range: 300-1300 ml/min) intra-operatively after HF-AVF reconstruction. At 6 and 12-months follow-up, the mean flow rates were 1132 ± 320 ml/min (range: 470-1700 ml/min) and 1453 ± 888 ml/min (range: 300-3800 ml/min), respectively. Recurrence of high flow (>1500 ml/min) occurred in 16% and 25% of the patients at 6 and 12 months and primary patency rates were 86% and 70%, respectively.

CONCLUSIONS

This early experience with novel external stenting for HF-AVF reconstruction demonstrates that it is a safe and effective method for reducing and stabilizing flow rates up to 1-year post procedure. Additional studies are required to evaluate the durability of this procedure over the longer term and assess its effect on cardiac remodeling.

Current considerations for heart-kidney transplantation

Cardiorenal syndrome is a complex syndrome characterized by dysfunction of the heart and kidneys in an interdependent fashion and is further divided into different subtypes based on primary organ dysfunction. Simultaneous Heart-Kidney transplantation is the treatment of choice for end-stage irreversible dysfunction of both organs, however it may be avoided with determination of cardiorenal subtype and management of primary organ dysfunction. This article discusses types of cardiorenal syndrome, indications and concerns regarding the use of simultaneous heart-kidney transplantation, and outlines algorithms for determination of need for dual vs. single organ transplantation.

Arteriovenous Fistulae in Chronic Kidney Disease and the Heart: Physiological, Histological, and Transcriptomic Characterization of a Novel Rat Model

Background Arteriovenous fistulae (AVFs) are the gold standard for vascular access in those requiring hemodialysis but may put an extra hemodynamic stress on the cardiovascular system. The complex interactions between the heart, kidney, and AVFs remain incompletely understood. Methods and Results We characterized a novel rat model of five-sixths partial nephrectomy (NX) and AVFs. NX induced increases in urea, creatinine, and hippuric acid. The addition of an AVF (AVF+NX) further increased urea and a number of uremic toxins such as trimethylamine N-oxide and led to increases in cardiac index, left and right ventricular volumes, and right ventricular mass. Plasma levels of uremic toxins correlated well with ventricular morphology and function. Heart transcriptomes identified altered expression of 8 genes following NX and 894 genes following AVF+NX, whereas 290 and 1431 genes were altered in the kidney transcriptomes, respectively. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed gene expression changes related to cell division and immune activation in both organs, suppression of ribosomes and transcriptional activity in the heart, and altered renin-angiotensin signaling as well as chronodisruption in the kidney. All except the latter were worsened in AVF+NX compared with NX. Conclusions Inflammation and organ dysfunction in chronic kidney disease are exacerbated following AVF creation. Furthermore, our study provides important information for the discovery of novel biomarkers and therapeutic targets in the management of cardiorenal syndrome.

Long-term impacts of different dialysis modalities on right ventricular function in patients with end-stage renal disease

BACKGROUND

Right ventricular dysfunction is a major cause of heart failure and mortality in end-stage renal disease patients. Scarce data is available regarding the comparison of echocardiographic right ventricular function in end-stage renal disease patients on hemodialysis (HD) and peritoneal dialysis (PD). The aim of the study was to evaluate the long-term impacts of different dialysis modalities on right ventricular function assessed by conventional echocardiography, in end-stage renal disease patients with preserved left ventricular function.

METHODS

The study included 120 patients grouped as follows: PD (n = 40), HD with arterio-venous fistula (n = 40), and healthy control subjects (n = 40). Conventional echocardiography was performed on all patients. A classification of right ventricular function was defined in HD patients by using tricuspid annular plane systolic excursion (TAPSE), right ventricular myocardial performance index (RV-MPI), fractional area change (FAC), and tricuspid lateral annulus systolic velocity (Sa) values. Correlation analysis was performed by using the right ventricular dysfunction score, clinical, and echocardiographic parameters.

RESULTS

The mean age of the study population was 51.9 ± 13.1 years and 47.5% were females. TAPSE and Sa velocity were found to be significantly lower and RV-MPI was significantly higher in patients undergoing HD, compared with control and PD patients. Logistic regression analysis showed that HD treatment was an independent risk factor for developing right ventricular dysfunction.

CONCLUSION

RV function was impaired in patients undergoing HD compared with patients on PD.

Iatrogenic Arteriovenous Fistula Secondary to Percutaneous Coronary Intervention Causing Severe Decompensated Heart Failure

Congestive heart failure has long been a well-known cause of both morbidity and mortality for thousands of people worldwide. Consequences of decompensated heart failure are systemic and widespread, including but not limited to pulmonary edema, dyspnea, hypoxia, peripheral edema, and end-organ hypoperfusion. Common etiologies of congestive heart failure include systemic hypertension, coronary artery disease, longstanding alcohol abuse, valvular dysfunctions, and myocarditis. While the vast majority of congestive heart failure cases are secondary to one of these common etiologies, there is a subset of cases that cannot be traced to any of these causes and are most often grouped under the category of idiopathic. One rarely seen etiology of decompensated heart failure is an arteriovenous fistula, whether naturally occurring or iatrogenic. We report a case of an iatrogenic AV fistula secondary to percutaneous coronary intervention causing severe decompensated heart failure that was successfully treated with surgical ligation.

High-flow arteriovenous fistula and myocardial fibrosis in hemodialysis patients with non-contrast cardiac magnetic resonance imaging

Background

The role of high-flow arteriovenous fistula (AVF) in cardiovascular morbidity in hemodialysis (HD) patients is very likely under-recognized. We assessed the relationship between high access flow (Qa) and myocardial fibrosis in HD patients.

Methods

Myocardial fibrosis was assessed by native T1 relaxation times on non-contrast cardiac magnetic resonance imaging and a potential marker of fibrosis. Serum levels of galectin-3, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and monocyte chemoattractant protein 1 (MCP-1) were measured in 101 HD patients who underwent regular monitoring of AVF Qa. A high-flow AVF was defined as a Qa >2 L/min.

Results

Hemodialysis patients showed significantly higher galectin-3 value and increased T1 relaxation time compared to healthy volunteers, suggesting increased myocardial fibrosis in uremic cardiomyopathy. In HD patients, 20 (19.8%) had a Qa > 2L/min, and they had significantly higher cardiac output, cardiac index, left ventricular mass, and increased T1 times than those with a Qa ≤ 2 L/min. Also, serum galectin-3 and NT-proBNP levels were much higher in the high Qa group, indicating a close relationship between the high Qa, increased myocardial fibrosis, and the risk of heart failure (HF) in HD patients. It is interesting that a higher AVF Qa for myocardial fibrosis was independent of several traditional cardiovascular risk factors as well as serum levels of NT-proBNP and MCP-1.

Conclusions

A supra-physiologically high Qa can be related to myocardial fibrosis and increased risk of HF in HD patients. Regular Qa monitoring could allow early detection of a high-flow AVF that could arise cardiac complications.

Hemodynamic and Clinical Determinants of Left Atrial Enlargement in Liver Transplant Candidates

New-onset heart failure is a frequent complication after orthotopic liver transplantation (OLT). Left atrial enlargement (LAE) may be a sign of occult left heart disease. Our primary objective was to determine invasive hemodynamic and clinical predictors of LAE and then investigate its effect on post-transplant outcomes. Of 609 subjects who received OLT between January 1, 2010, and October 1, 2018, 145 who underwent preoperative right-sided cardiac catheterization and transthoracic echocardiography were included. Seventy-eight subjects (54%) had pretransplant LAE. Those with LAE had significantly lower systemic vascular resistance with higher cardiac and stroke volume index (61.0 vs 51.7 ml/m²; p <0.001), but there was no difference in pulmonary artery wedge pressure. There was a linear relation between left atrial volume index and stroke volume index (R² = 0.490, p<0.001), but not pulmonary artery wedge pressure. The presence of severe LAE was associated with a reduced likelihood (hazard ratio = 0.26, p = 0.033) of reaching the composite end point of new-onset systolic heart failure, heart failure hospitalization, or heart failure death within 12 months post-transplant. There was also a significant reduction in LAE after transplantation (p = 0.013). In conclusion, LAE was common in OLT recipients and was more closely associated with stroke volume than left heart filling pressures. The presence of LAE was associated with a reduced likelihood of reaching composite outcomes and tended to regress after transplant.

Latent Pulmonary Vascular Disease May Alter the Response to Therapeutic Atrial Shunt Device in Heart Failure

BACKGROUND

In REDUCE LAP-HF II (A Study to Evaluate the Corvia Medical, Inc IASD System II to Reduce Elevated Left Atrial Pressure in Patients With Heart Failure), implantation of an atrial shunt device did not provide overall clinical benefit for patients with heart failure with preserved or mildly reduced ejection fraction. However, prespecified analyses identified differences in response in subgroups defined by pulmonary artery systolic pressure during submaximal exercise, right atrial volume, and sex. Shunt implantation reduces left atrial pressures but increases pulmonary blood flow, which may be poorly tolerated in patients with pulmonary vascular disease (PVD). On the basis of these results, we hypothesized that patients with latent PVD, defined as elevated pulmonary vascular resistance during exercise, might be harmed by shunt implantation, and conversely that patients without PVD might benefit.

METHODS

REDUCE LAP-HF II enrolled 626 patients with heart failure, ejection fraction ≥40%, exercise pulmonary capillary wedge pressure ≥25 mm Hg, and resting pulmonary vascular resistance <3.5 Wood units who were randomized 1:1 to atrial shunt device or sham control. The primary outcome-a hierarchical composite of cardiovascular death, nonfatal ischemic stroke, recurrent HF events, and change in health status-was analyzed using the win ratio. Latent PVD was defined as pulmonary vascular resistance ≥1.74 Wood units (highest tertile) at peak exercise, measured before randomization.

RESULTS

Compared with patients without PVD (n=382), those with latent PVD (n=188) were older, had more atrial fibrillation and right heart dysfunction, and were more likely to have elevated left atrial pressure at rest. Shunt treatment was associated with worse outcomes in patients with PVD (win ratio, 0.60 [95% CI, 0.42, 0.86]; P=0.005) and signal of clinical benefit in patients without PVD (win ratio, 1.31 [95% CI, 1.02, 1.68]; P=0.038). Patients with larger right atrial volumes and men had worse outcomes with the device and both groups were more likely to have pacemakers, heart failure with mildly reduced ejection fraction, and increased left atrial volume. For patients without latent PVD or pacemaker (n=313; 50% of randomized patients), shunt treatment resulted in more robust signal of clinical benefit (win ratio, 1.51 [95% CI, 1.14, 2.00]; P=0.004).

CONCLUSIONS

In patients with heart failure with preserved or mildly reduced ejection fraction, the presence of latent PVD uncovered by invasive hemodynamic exercise testing identifies patients who may worsen with atrial shunt therapy, whereas those without latent PVD may benefit.

Association between arteriovenous access flow and ventricular function: A cross-sectional study

Background

Permanent hemodialysis access comes with a myriad of problems on top of the well-known benefits; flow disturbances, risk of infection and revision being among them. All of these could eventually lead to impaired cardiac function. Even so, the relationship between impaired cardiac function due to arteriovenous access in patients undergoing hemodialysis has not been clearly described. This study aimed to analyze the relationship of flow in an artificial arteriovenous access with left and right ventricular function in patients with chronic kidney disease (CKD) undergoing hemodialysis at a referral hospital in Indonesia.

Material and methods

This was a cross sectional study with consecutive sampling technique. Samples were patients with CKD undergoing hemodialysis at Dr. Soetomo General Hospital from December 2021to January 2022. A total of 47 patients who met the inclusion criteria underwent Doppler ultrasound to assess arteriovenous access flow and transthoracic echocardiography to assess left and right ventricle function.

Results

From 47 patients, 26 (55.3%) had high arteriovenous access flow. The clinical characteristics of the patients between the high and low arteriovenous access flow groups were not significantly different. We found that the value of left ventricular ejection fraction in the non-high-flow access group was significantly higher than the high-flow access group (p < 0.05). Other than that, the median right ventricle fractional area changes in the non-high-flow access group was also higher than the high-flow access group (p < 0.05).

Conclusion

Arteriovenous access flow as measured by Doppler ultrasonography has a significant relationship with impaired left and right ventricular functions based on systolic function parameters from echocardiography.

•

There is an association between arteriovenous access flow and ventricular function.

•

The higher the access flow, the lower the left ventricular systolic function.

•

The higher the access flow, the lower the right ventricular systolic function.

•

It is important to periodically evaluate the access flow of hemodialysis patients.

Clinical and Haemodynamic Effects of Arteriovenous Shunts in Patients with Heart Failure with Preserved Ejection Fraction

The arteriovenous shunt (AVS) is the most commonly used vascular access in patients receiving regular haemodialysis. The AVS may have a significant haemodynamic impact on patients with heart failure. Many studies have sought to understand the effect of AVS creation or closure on heart structure and functions, most of which use non-invasive methods, such as echocardiography or cardiac MRI. Data are mainly focused on heart failure with reduced ejection fraction and there are limited data on heart failure with preserved ejection fraction. The presence of an AVS has a significant haemodynamic impact on the cardiovascular system and it is a common cause of high-output cardiac failure. Given that most studies to date use non-invasive methods, invasive assessment of the haemodynamic effects of the AVS using a right heart catheter may provide additional valuable information.

Brachial artery transposition versus catheters as tertiary vascular access for maintenance hemodialysis: a single-center retrospective study

Some hemodialysis patients are not suitable for creation of an arteriovenous fistula (AVF) or arteriovenous graft (AVG). However, they can receive a tunneled cuffed central venous catheter (tcCVC), but this carries risks of infection and mortality. We aimed to evaluate the safety and effectiveness of brachial artery transposition (BAT) versus those of tcCVC. This retrospective study evaluated hemodialysis patients who underwent BAT or tcCVC placement because of severe heart failure, hand ischemia, central venous stenosis or occlusion, inadequate vessels for creating standard arteriovenous access, or limited life expectancy. The primary outcome was whole access circuit patency. Thirty-eight patients who underwent BAT and 25 who underwent tcCVC placement were included. One-year patency rates for the whole access circuit were 84.6% and 44.9% in the BAT and tcCVC groups, respectively. The BAT group was more likely to maintain patency (unadjusted hazard ratio: 0.17, 95% confidence interval: 0.05–0.60, p = 0.006). The two groups did not have significantly different overall survival (log-rank p = 0.146), although severe complications were less common in the BAT group (3% vs. 28%, p = 0.005). Relative to tcCVC placement, BAT is safe and effective with acceptable patency in hemodialysis patients not suitable for AVF or AVG creation.

The unmet need of evidence-based therapy for patients with advanced chronic kidney disease and heart failure: Position paper from the Cardiorenal Working Groups of the Spanish Society of Nephrology and the Spanish Society of Cardiology

Despite the high prevalence of chronic kidney disease (CKD) and its high cardiovascular risk, patients with CKD, especially those with advanced CKD (stages 4-5 and patients on kidney replacement therapy), are excluded from most cardiovascular clinical trials. It is particularly relevant in patients with advanced CKD and heart failure (HF) who have been underrepresented in many pivotal randomized trials that have modified the management of HF. For this reason, there is little or no direct evidence for HF therapies in patients with advanced CKD and treatment is extrapolated from patients without CKD or patients with earlier CKD stages. The major consequence of the lack of direct evidence is the under-prescription of HF drugs to this patient population. As patients with advanced CKD and HF represent probably the highest cardiovascular risk population, the exclusion of these patients from HF trials is a serious deontological fault that must be solved. There is an urgent need to generate evidence on how to treat HF in patients with advanced CKD. This article briefly reviews the management challenges posed by HF in patients with CKD and proposes a road map to address them.

Chronic Kidney Disease and Heart Failure-Everyday Diagnostic Challenges

Is advanced chronic kidney disease (CKD) a cardiac “no man’s land”? Chronic heart failure (HF) is widely believed to be one of the most serious medical challenges of the 21st century. Moreover, the number of patients with CKD is increasing. To date, patients with estimated glomerular filtration rates <30 mL/min/1.73 m² have frequently been excluded from large, randomized clinical trials. Although this situation is slowly changing, in everyday practice we continue to struggle with problems that are not clearly addressed in the guidelines. This literature review was conducted by an interdisciplinary group, which comprised a nephrologist, internal medicine specialists, and cardiologist. In this review, we discuss the difficulties in ruling out HF for patients with advanced CKD and issues regarding the cardiotoxicity of dialysis fistulas and the occurrence of pulmonary hypertension in patients with CKD. Due to the recent publication of the new HF guidelines by the European Society of Cardiology, this is a good time to address these difficult issues. Contrary to appearances, these are not niche issues, but problems that affect many patients.

High-flow arteriovenous fistula and hemodynamic consequences at 1 year after kidney transplantation

INTRODUCTION

There are only scarce data regarding the cardiovascular impact of arteriovenous fistula after kidney transplantation depending on fistula flow.

METHODS

We performed a single-center, prospective, cohort study including 49 patients with a functional fistula at 1 year from kidney transplantation. Patients were convened for a clinical work-up, a biological analysis, a fistula's Doppler ultrasonography and an echocardiography. Main judgment criterion was comparison of echocardiography parameters between patients with relative (fistula flow >1 L/min and a fistula flow/cardiac output ratio >20%), absolute high-flow fistula (fistula flow >2 L/min) and normal-flow fistula.

RESULTS

High-flow fistula frequency was 69%. Significantly higher left ventricular end-diastolic and systolic diameters were observed in this group compared with the normal-flow fistula group (53 ± 6 vs. 48 ± 7 mm; p = 0.04 and 33 ± 6 vs. 28 ± 8 mm; p = 0.02) and between the absolute and relative high-flow fistula subgroups (56 ± 6 vs. 51 ± 6 mm; p = 0.009 and 35 ± 6 vs. 31 ± 5 mm; p = 0.01). The study showed no other significant differences.

CONCLUSIONS

This study showed a significantly higher but not pathological left ventricular end-diastolic and systolic diameters values in patients with high-flow fistula compared with patients with normal-flow fistula and between patients with respectively absolute and relative high-flow fistula.

Relationship of Nonalcoholic Fatty Liver Disease and Heart Failure With Preserved Ejection Fraction

Although there is an established bidirectional relationship between heart failure with reduced ejection fraction and liver disease, the association between heart failure with preserved ejection fraction (HFpEF) and liver diseases, such as nonalcoholic fatty liver disease (NAFLD), has not been well explored. In this paper, the authors provide an in-depth review of the relationship between HFpEF and NAFLD and propose 3 NAFLD-related HFpEF phenotypes (obstructive HFpEF, metabolic HFpEF, and advanced liver fibrosis HFpEF). The authors also discuss diagnostic challenges related to the concurrent presence of NAFLD and HFpEF and offer several treatment options for NAFLD-related HFpEF phenotypes. The authors propose that NAFLD-related HFpEF should be recognized as a distinct HFpEF phenotype.

Hemodialysis vascular access affects heart function and outcomes: Tips for choosing the right access for the individual patient

Chronic kidney disease is associated with increased cardiovascular morbidity and mortality. A well-functioning vascular access is associated with improved survival and among the available types of vascular access the arterio-venous (AV) fistula is the one associated with the best outcomes. However, AV access may affect heart function and, in some patients, could worsen the clinical status. This review article focuses on the specific cardiovascular hemodynamics of dialysis patients and how it is affected by the AV access; the effects of an excessive increase in AV access flow, leading to high-output heart failure; congestive heart failure in CKD patients and the contraindications to AV access; pulmonary hypertension. In severe heart failure, peritoneal dialysis (PD) might be the better choice for cardiac health, but if contraindicated suggestions for vascular access selection are provided based on the individual clinical presentation. Management of the AV access after kidney transplantation is also addressed, considering the cardiovascular benefit of AV access ligation compared to the advantage of having a functioning AVF as backup in case of allograft failure. In PD patients, who need to switch to hemodialysis, vascular access should be created timely. The influence of AV access in patients undergoing cardiac surgery for valvular or ischemic heart disease is also addressed. Cardiovascular implantable electronic devices are increasingly implanted in dialysis patients, but when doing so, the type and location of vascular access should be considered.

An indolent cause of high-output heart failure in end-stage kidney disease-Application of the Nicoladoni-Israel-Branham test: A case report

BACKGROUND

A hemodynamically significant arteriovenous fistula (AVF) in end-stage kidney disease (ESKD) causes a high flow state, resulting in pathologic cardiovascular remodeling, and deserves timely clinical recognition.

CASE

A 55-year-old woman with history of ESKD with deceased donor kidney transplant with failing graft function and baseline creatinine of 2.8 mg/dl presented to the clinic with nocturnal cough, orthopnea, dyspnea on exertion and pedal edema. Physical exam was notable for large, aneurysmal right brachial AVF. Transthoracic echocardiography (TTE) revealed left ventricular (LV) enlargement and hypertrophy and elevated cardiac output (CO) of 10 L/min, raising a clinical concern for high-output heart failure.

DECISION MAKING

A non-invasive assessment of the hemodynamic significance of the AVF was performed using a TTE. During temporary occlusion of the AVF, it was determined that about 27% of the resting CO was attributed to the AVF, suggesting hemodynamic significance. Nicoladoni-Israel-Branham sign was negative as there was no change in patient's heart rate, but this was potentially attributed to beta-blockade and chronic loading conditions. She underwent AVF banding and 2-month later her presenting symptoms resolved, and a TTE showed a decrease in resting CO of 7.6 L/min with normalization of LV size.

CONCLUSION

This case highlights several teaching points. Firstly, in patients with ESKD, a large AVF can contribute to a high CO state resulting in maladaptive cardiovascular remodeling. Secondly, TTE evaluation of the hemodynamic contribution of an AVF can be performed with the application of the Nicoladoni-Israel-Branham sign. Finally, some experts recommend pre-emptive banding or ligation of AVF after successful kidney transplantation as this has been shown to have symptomatic and cardiovascular benefits.

Successful embolization of a renal arteriovenous fistula; a feared kidney biopsy complication

The authors report a case of a 57-year-old woman who was successfully treated with a percutaneous embolization procedure for a renal arteriovenous fistula that developed as a complication of a kidney biopsy. An acute kidney injury that failed to resolve with medical management prompted further investigation with a renal biopsy. Five hours after the kidney biopsy, the patient became hemodynamically unstable with a blood pressure of 77 of 52 mm Hg. A stat abdominal computed tomography scan without contrast discovered a large left-sided perinephric hematoma that measured up to 11.5 cm with a moderate amount of perinephric blood. An angiogram subsequently demonstrated the presence of an arteriovenous fistula at the inferior pole of the left kidney. Several 2 × 3 mm and 3 × 3 mm coils were deployed into two separate segmental branches of the inferior pole, and the post embolization angiogram confirmed resolution of the previously visualized arteriovenous fistula.

Arteriovenous Fistula-induced Cardiac Remodeling Shows Cardioprotective Features in Mice

Objective

Arteriovenous fistulae (AVF) placed for hemodialysis have high flow rates that can stimulate left ventricular (LV) hypertrophy. LV hypertrophy generally portends poor cardiac outcomes, yet clinical studies point to superior cardiac-specific outcomes for patients with AVF when compared with other dialysis modalities. We hypothesize that AVF induce physiologic cardiac hypertrophy with cardioprotective features.

Methods

We treated 9- to 11-week-old C57Bl/6 male and female mice with sham laparotomy or an aortocaval fistula via a 25G needle. Cardiac chamber size and function were assessed with serial echocardiography, and cardiac computed tomography angiography. Hearts were harvested at 5 weeks postoperatively, and the collagen content was assessed with Masson's trichrome. Bulk messenger RNA sequencing was performed from LV of sham and AVF mice at 10 days. Differentially expressed genes were analyzed using Ingenuity Pathway Analysis (Qiagen) to identify affected pathways and predict downstream biological effects.

Results

Mice with AVF had similar body weight and wet lung mass, but increased cardiac mass compared with sham-operated mice. AVF increased cardiac output while preserving LV systolic and diastolic function, as well as indices of right heart function; all four cardiac chambers were enlarged, with a slight decrement in the relative LV wall thickness. Histology showed preserved collagen density within each of the four chambers without areas of fibrosis. RNA sequencing captured 19 384 genes, of which 857 were significantly differentially expressed, including transcripts from extracellular matrix-related genes, ion channels, metabolism, and cardiac fetal genes. The top upstream regulatory molecules predicted include activation of angiogenic (Vegf, Akt1), procardiomyocyte survival (Hgf, Foxm1, Erbb2, Lin9, Areg), and inflammation-related (CSF2, Tgfb1, TNF, Ifng, Ccr2, IL6) genes, as well as the inactivation of cardiomyocyte antiproliferative factors (Cdkn1a, FoxO3, α-catenin). The predicted downstream effects include a decrease in heart damage, and increased arrhythmia, angiogenesis, and cardiogenesis. There were no significant sex-dependent differences in the AVF-stimulated cardiac adaptation.

Conclusions

AVF stimulate adaptive cardiac hypertrophy in wild-type mice without heart failure or pathologic fibrosis. Transcriptional correlates suggest AVF-induced cardiac remodeling has some cardioprotective, although also arrhythmogenic features. (JVS–Vascular Science 2021;2:110-28.)

Clinical Relevance

Arteriovenous fistulae (AVF) are commonly used as access for hemodialysis in patients with end-stage renal disease. AVF induce a high-output state that is associated with long-term structural cardiac remodeling, including left ventricle hypertrophy, but this element has uncertain clinical significance. Although left ventricle hypertrophy has traditionally been associated with an increased risk of cardiovascular disease, clinical studies have suggested that cardiac-specific outcomes of patients with end-stage renal disease were better with AVF compared with other dialysis modalities. This study uses a mouse model of AVF to study the structural, functional, and molecular correlates of AVF-induced cardiac remodeling. It finds that AVF causes an adaptive cardiac hypertrophy without functional decline or fibrosis. Transcriptional correlates suggest an electrical remodeling and the upregulation of proangiogenic, procardiogenic, and prosurvival factors, implying that AVF-induced cardiac hypertrophy is potentially cardioprotective, but also arrhythmogenic.

Access flow volume (Qa) and survival in a hemodialysis population: An analysis of 5208 Qa measurements over a 9-year period

BACKGROUND

Aim of the study was to determine associations between characteristics of arteriovenous access (AVA) access flow volume (Qa, mL/min) and four year freedom from cardiovascular mortality (4yr-CVM) in hemodialysis (HD) patients.

METHODS

HD patients who received a primary AVA between January 2010 and December 2017 in one center were analyzed. Initial Qa was defined as the first Qa value obtained in a well-functioning AVA by a two-needle dilution technique. Actual Qa was defined as access flow at a random point of time. Changes in actual Qa were expressed per 3-month periods. CVM was assessed according to the ERA-EDTA classification. The optimal cut-off point for initial Qa was identified by a receiver operating characteristic curve. A joint modelling statistical technique determined longitudinal associations between Qa characteristics and 4yr-CVM.

RESULTS

A total of 5208 Qa measurements (165 patients, male n = 103; age 70±12 years, autologous AVA n = 146, graft n = 19) were analyzed. During follow-up (Dec 2010-Jan 2018, median 36 months), 79 patients (48%) died. An initial Qa < 900 mL/min was associated with an increased 4y-CVM risk (HR: 4.05; 95% CI [1.94-8.43], P<0.001). After 4 years, freedom from CVM was 34% lower in patients with a Qa < 900 mL/min (53 ±7% vs. Qa ≥ 900 mL/min: 87 ±4%, P <0.001). An association between increases in actual Qa over 3-month periods and mortality was found (HR: 4.48 per 100mL/min, 95% CI [1.44-13.97], P =0.010) indicating that patients demonstrating increasing Qa were more likely to die. By contrast, actual Qa per se was not related to survival.

CONCLUSIONS

Studying novel arteriovenous access Qa characteristics may contribute to understanding excess CVM in HD patients.

Pulmonary Hypertension in Left Heart Disease

Pulmonary hypertension is common in left heart disease and is related most commonly to passive back transmission of elevated left atrial pressures. Some patients, however, may develop pulmonary vascular remodeling superimposed on their left-sided heart disease. This review provides a contemporary appraisal of existing criteria to diagnose a precapillary component to pulmonary hypertension in left heart disease as well as discusses etiologies, management issues, and future directions.

Predialysis predictors for identifying patients requiring dialysis at a higher glomerular filtration rate

Background

Current evidence suggests that the initiation of maintenance hemodialysis should not be based on a specific glomerular filtration rate (GFR) but on symptoms or signs attributable to kidney disease. However, it is difficult to predict the time point at which overt uremic syndrome develops in individuals. The estimated GFR is poorly correlated with occurrence of uremic symptoms, and some patients require dialysis at a higher eGFR than others. In this case, patients are more likely to be improperly prepared for dialysis. We investigated the predialysis characteristics of patients who require dialysis at a higher eGFR.

Methods

A total of 453 incident dialysis patients being monitored by a nephrologist from January 2013 to December 2018 were included. The predialysis characteristics when eGFR decreased to 20 mL/min/1.73 m² were obtained.

Results

The mean age was 61 years, and 65.7% were men. Overall, the median eGFR at the first dialysis was 5.8 (interquartile range 4.6–7.3) mL/min/1.73 m² and initiation of dialysis at the first quintile (≥7.8 mL/min/1.73 m²) was defined as ‘early initiation of dialysis’ Among the predialysis characteristics, heart failure (adjusted odds ratio 3.68; 95% confidence interval, 1.59–8.03), serum albumin <4.0 mg/dL (2.22; 1.30–3.77), blood urea nitrogen (BUN)/creatinine (Cr) ratio >15 mg/mg (1.92, 1.16–3.18), and hyperuricemia (1.84; 1.05–3.23) were independent predictors of early initiation. Diabetes mellitus and the causes of kidney disease were not independent predictors of early initiation. The early initiation group was less likely to initiate dialysis with a permanent vascular access than the late initiation group.

Conclusions

For patients with heart failure, low serum albumin level, high BUN/Cr ratio, or hyperuricemia, clinicians can provide predialysis counseling in advance and consider early creation of vascular access.

Management of Heart Failure Patient with CKD

CKD is common in patients with heart failure, associated with high mortality and morbidity, which is even higher in people undergoing long-term dialysis. Despite increasing use of evidence-based drug and device therapy in patients with heart failure in the general population, patients with CKD have not benefitted. This review discusses prevalence and evidence of kidney replacement, device, and drug therapies for heart failure in CKD. Evidence for treatment with β-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, angiotensin receptor neprilysin inhibitors, and sodium-glucose cotransporter inhibitors in mild-to-moderate CKD has emerged from general population studies in patients with heart failure with reduced ejection fraction (HFrEF). β-Blockers have been shown to improve outcomes in patients with HFrEF in all stages of CKD, including patients on dialysis. However, studies of HFrEF selected patients with creatinine <2.5 mg/dl for ACE inhibitors, <3.0 mg/dl for angiotensin-receptor blockers, and <2.5 mg/dl for mineralocorticoid receptor antagonists, excluding patients with severe CKD. Angiotensin receptor neprilysin inhibitor therapy was successfully used in randomized trials in patients with eGFR as low as 20 ml/min per 1.73 m2 Hence, the benefits of renin-angiotensin-aldosterone axis inhibitor therapy in patients with mild-to-moderate CKD have been demonstrated, yet such therapy is not used in all suitable patients because of fear of hyperkalemia and worsening kidney function. Sodium-glucose cotransporter inhibitor therapy improved mortality and hospitalization in patients with HFrEF and CKD stages 3 and 4 (eGFR>20 ml/min per 1.73 m2). High-dose and combination diuretic therapy, often necessary, may be complicated with worsening kidney function and electrolyte imbalances, but has been used successfully in patients with CKD stages 3 and 4. Intravenous iron improved symptoms in patients with heart failure and CKD stage 3; and high-dose iron reduced heart failure hospitalizations by 44% in patients on dialysis. Cardiac resynchronization therapy reduced death and hospitalizations in patients with heart failure and CKD stage 3. Peritoneal dialysis in patients with symptomatic fluid overload improved symptoms and prevented hospital admissions. Evidence suggests that combined cardiology-nephrology clinics may help improve management of patients with HFrEF and CKD. A multidisciplinary approach may be necessary for implementation of evidence-based therapy.

Impact of a change in vascular access flow volume after percutaneous transluminal angioplasty on cardiac function

Vascular access (VA) is necessary for patients on hemodialysis, and percutaneous transluminal angioplasty (PTA) is a useful treatment for maintaining VA function. PTA immediately increases the VA flow volume, which can affect cardiac function. We investigated the relationship between changes in VA flow volume and cardiac function in patients who underwent PTA. This was a single-center retrospective observational study, including patients who underwent PTA between June 2016 and August 2016. VA flow volume and cardiac function were measured by sonography before and 1 h after PTA. This study included 50 PTA procedures in 50 cases. PTA significantly increased the median VA flow volume from 445 (range, 150-1229) to 725 (350-1268) mL/min. Although the ejection fraction and diameter of the inferior vena cava were unchanged, the cardiac output (CO) and cardiac index increased significantly in most cases. Surprisingly, the CO was decreased in 18% of cases despite the increased VA flow volume. In this atypical group, a high CO before PTA was found to be a significant factor for the decrease in CO by PTA. In most cases, both VA flow volume and CO were increased by PTA, whereas in some cases, the CO was decreased despite an increase in VA flow volume. This atypical phenomenon may be due to the insufficient adaptive response in the peripheral artery and heart and could predict risks for future cardiac events. Therefore, it is important that such patients are carefully followed up on.

High-flow arteriovenous fistula is not associated with increased extracellular volume or right ventricular dysfunction in haemodialysis patients

BACKGROUND

High-output congestive heart failure secondary to high-flow arteriovenous fistula (AVF) has been reported in haemodialysis (HD) patients. As high-flow AVF (HFA) would be expected to result in fluid retention, we conducted an observational study to characterize the relationship between AVF flow (Qa) and extracellular water (ECW) in HD patients.

METHODS

We measured Qa by ultrasound dilution in prevalent HD outpatients with an AVF in two dialysis centres. The ECW:total body water (TBW) ratio was measured both pre- and post-dialysis by multifrequency bioimpedance analysis. Transthoracic echocardiograms (TTEs) were performed as part of routine clinical management.

RESULTS

We included 140 patients, mean age 62.7 ± 15.7 years, 60.7% male, 47.9% diabetic and 22.9% with coronary revascularization. Mean Qa was 1339 ± 761 mL/min and 22 (15.7%) patients had HFA defined as Qa >2.0 L/min. Qa was positively associated with an upper arm AVF (P = 0.005), body mass index (P = 0.012) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (P = 0.047) and negatively associated with diabetes (P < 0.001) and coronary revascularization (P = 0.005). The ECW:TBW ratio was positively associated with age (P < 0.001), Davies comorbidity index (P = 0.034), peripheral vascular disease (P = 0.030) and NT-proBNP (P = 0.002) and negatively associated with serum albumin (P < 0.001). Qa was not associated with the ECW:TBW ratio (P = 0.744). TTE parameters were not associated with Qa.

CONCLUSIONS

In our outpatient HD cohort, high AVF flow was not associated with ECW expansion, either pre- or post-dialysis when accounting for potential confounders. By controlling ECW, high access flow should not necessarily be perceived as a threat to cardiovascular physiology.