Effect of the arteriovenous access for hemodialysis on subendocardial viability ratio, pulse pressure and hospitalizations

Prehemodialysis arteriovenous access creation is associated with better cardiovascular outcomes in patients receiving hemodialysis: a population-based cohort study

Background

Cardiovascular (CV) disease contributes to nearly half of the mortalities in patients with end-stage renal disease. Patients who received prehemodialysis arteriovenous access (pre-HD AVA) creation had divergent CV outcomes.

Methods

We conducted a population-based cohort study by recruiting incident patients receiving HD from 2001 to 2012 from the Taiwan National Health Insurance Research Database. Patients’ characteristics, comorbidities, and medicines were analyzed. The primary outcome of interest was major adverse cardiovascular events (MACEs), defined as hospitalization due to acute myocardial infarction, stroke, or congestive heart failure (CHF) occurring within the first year of HD. Secondary outcomes included MACE-related mortality and all-cause mortality in the same follow-up period.

Results

The patients in the pre-HD AVA group were younger, had a lower burden of underlying diseases, were more likely to use erythropoiesis-stimulating agents but less likely to use renin–angiotensin–aldosterone system blockers. The patients with pre-HD AVA creation had a marginally lower rate of MACEs but a significant 35% lower rate of CHF hospitalization than those without creation (adjusted hazard ratio (HR) 0.65, 95% confidence interval (CI) [0.48–0.88]). In addition, the pre-HD AVA group exhibited an insignificantly lower rate of MACE-related mortality but a significantly 52% lower rate of all-cause mortality than the non-pre-HD AVA group (adjusted HR 0.48, 95% CI [0.39–0.59]). Sensitivity analyses obtained consistent results.

Conclusions

Pre-HD AVA creation is associated with a lower rate of CHF hospitalization and overall death in the first year of dialysis.

Effects of Arteriovenous Fistula on Blood Pressure in Patients With End-Stage Renal Disease: A Systematic Meta-Analysis

Background Central arteriovenous fistula ( AVF ) creation is under investigation for treatment of severe hypertension. We evaluated the effects of AVF for initiation of hemodialysis on systolic, diastolic, and mean arterial blood pressure in patients with end-stage renal disease. Methods and Results Data search included PubMed, Web of Science, and the Cochrane Library. A systematic review and meta-analysis of peer-reviewed studies reporting the effects of the creation/ligation of an AVF on blood pressure in patients with end-stage renal disease was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis), PRISMA -P (PRISMA for systematic review protocols), and ROBINS-I (Risk of Bias in Non-Randomized Studies) criteria by the Cochrane Bias Methods Group. All studies in which the results could have been biased by hemodialysis were excluded. A total of 14 trials including 412 patients with end-stage renal disease ( AVF creation, n=185; AVF ligation, n=227) fulfilled the criteria and were subsequently analyzed. Average blood pressure in patients with no/closed AVF was 140.5/77.6 mm Hg with a mean arterial blood pressure of 96.1 mm Hg. Following creation of AVF , systolic blood pressure significantly decreased by 8.7 mm Hg ( P<0.001), diastolic blood pressure by 5.9 mm Hg ( P<0.001), and mean arterial blood pressure by 6.6 mm Hg ( P=0.02), whereas after ligation systolic blood pressure increased by 5.2 mm Hg ( P=0.07), diastolic blood pressure by 3.8 mm Hg ( P=0.02), and mean arterial blood pressure by 3.7 mm Hg ( P=0.07) during short- to long-term follow-up. Conclusions Creation of AVF significantly decreases blood pressure in patients with end-stage renal disease, whereas blood pressure tends to increase after ligation. These findings illustrate the hemodynamic consequences of AVF which are under investigation for severe hypertension.

Preserved Cardiac Blood Supply-Workload Balance in Pediatric Patients After Aortic Arch Repair

One of the most important problems in patients with aortic coarctation after aortic arch repair is future cardiovascular disease. We have previously reported that the enhancement of aortic pressure wave reflection in patients could be one of the causes of future cardiovascular diseases, because it results in an increase of the left ventricular workload and is disadvantageous for coronary circulation. Seventeen patients who had undergone aortic arch repair without pressure gradient in their aortic arch were enrolled. An ascending aortic pressure waveform was recorded by a pressure-sensor-mounted catheter, and a subendocardial viability ratio, which measures cardiac blood supply-workload balance, was calculated. The values were compared with those in age-matched controls. The patients' mean age was 6.8 ± 2.8 years. The mean ascending aortic systolic pressure was higher (100.4 ± 12.9 vs. 90.2 ± 8.9 mmHg, p = 0.0011) and the pulse pressure was wider (38.1 ± 7.1 vs. 32.5 ± 5.4 mmHg, p = 0.0072) in patients than in control subjects. There was no difference in the mean subendocardial viability ratio (1.01 ± 0.25 vs. 1.01 ± 0.24, ns), while the mean tension time index (27.4 ± 5.6 vs. 23.0 ± 3.3, p = 0.0001) and diastolic pressure time index (28.4 ± 11.1 vs. 23.6 ± 8.0, p = 0.0082) were higher in patients than in controls. The cardiac blood supply-workload balance was preserved in patients after aortic arch repair, despite an increase in their cardiac workload.

Vascular access should be tailored to the patient

A cornerstone of hemodialysis treatment is the creation of a functional and durable dialysis vascular access. Every patient with chronic kidney disease should have a plan of renal replacement therapy and access site protection. Factors having a crucial impact on vascular access selection include age, comorbidity, vessel quality, prognosis, dialysis urgency, and surgeon's preferences. Our medical group have reviewed these factors in our patients and, based on recently published data, developed a clinical decision tree for dialysis access in the chronic kidney disease patient. Vascular access care should be patient-centered with the aim to maximize patient survival without loss of vascular access options; and not focused only the primary patency rates of dialysis access procedures.

Subendocardial Viability Ratio Is Impaired in Highly Proteinuric Chronic Kidney Disease Patients With Low Estimated Glomerular Filtration Rate

Proteinuria and estimated glomerular filtration rate (eGFR) are markers of chronic kidney disease (CKD) and cardiovascular disease. With applanation tonometry, pulse wave analysis and many hemodynamic data are available. One of them is the subendocardial viability ratio (SEVR) which represents a non-invasive measure of myocardial perfusion related to the work of the heart. The aim of our study was to investigate the importance of SEVR in proteinuric CKD patients and healthy subjects. We performed a cross-sectional study in a cohort of 90 non-dialysis CKD patients and 39 healthy controls. SEVR was assessed by radial applanation tonometry (SphygmoCor, Atcor, Australia). Blood samples and urine albumin-to-creatinine ratio (UACR) were analyzed. CKD patients were divided in four groups according to the UACR and eGFR: CKD group 1: UACR > 1000 mg/g and eGFR < 30 mL/min; CKD group 2: UACR > 1000 mg/g and eGFR >30 mL/min; CKD group 3: UACR <1000 mg/g and eGFR < 30 mL/min and CKD group 4: UACR < 1000 mg/g and eGFR >30 mL/min. Using one-way ANOVA, we found a statistically significant difference in SEVR only between CKD group 1 and all other CKD groups and healthy control group (P < 0.022). Results of our study show that only CKD patients with UACR more than 1000 mg/g and eGFR below 30 mL/min have significantly lower SEVR.

Hemodialysis decreases carotid-brachial and carotid-femoral pulse wave velocities: A 5-year follow-up study

Aortic stiffness is a prognostic parameter associated with patient mortality. Vascular access creation has been shown to have effects on arterial stiffness both in the aorta and in the upper limb arteries in chronically hemodialyzed patients (CHPs). However, no longitudinal studies have been conducted in order to characterize the evolution of arterial stiffness in CHPs. The aims of this work were (a) to measure baseline pulse wave velocity (PWV) in the carotid-femoral and in right and left carotid-brachial pathways in a cohort of CHP and (b) to conduct a 5-year prospective study on the same cohort to determine possible time-related differences. Pulse wave velocity was measured both in the carotid-femoral and in the carotid-brachial pathways, and clinical and biochemical parameters were collected in 25 CHPs, which were followed up after a 5-year lapse. Right and left carotid-brachial pathway PWV values showed significant decreases after the 5-year follow-up, independently of the presence of the vascular access (P < 0.001). Additionally, baseline carotid-brachial PWV was significantly higher (P < 0.001) than values measured 5 years later for upper limbs with vascular access (11.97 ± 2.97 m/sec vs. 6.76 ± 1.48 m/sec, respectively) and without vascular access (12.25 ± 2.38 m/sec vs. 7.18 ± 1.88 m/sec, respectively). Similarly, PWV values in the carotid-femoral pathway decreased significantly (P < 0.001) over the same period (13.27 ± 2.96 m/sec vs. 9.75 ± 2.99 m/sec, respectively). The 5-year follow-up of PWV showed significant decreases in both carotid-brachial and carotid-femoral pathways. The general changes in arterial stiffness could be related to the vascular access creation, hemodialysis therapy, and to the improvement of arterial pressure management.