Ultrasonographic Assessment of Atherosclerotic Renal Artery Stenosis in Elderly Patients with Chronic Kidney Disease: An Italian Cohort Study

Application of simple ultrasound Doppler hemodynamic parameters in the diagnosis of severe renal artery stenosis in routine clinical practice

Background

Doppler ultrasound (DUS) is recommended in first-line imaging for the diagnosis of renal artery stenosis (RAS). However, the correct selection of Doppler direct or indirect parameters and their optimal thresholds remain controversial. This study explored simple ultrasound Doppler parameters to diagnose severe RAS (RAS ≥70%) in routine clinical practice.

Methods

In this retrospective study, patients with clinically suspected renovascular hypertension who first underwent renal artery DUS and contrast-enhanced ultrasound (CEUS) and subsequent digital subtraction angiography (DSA) or computed tomography angiography (CTA) were consecutively included. Clinical characteristics and ultrasound Doppler hemodynamic parameters were collected, including peak systolic velocity (PSV), the ratio of the peak velocities in the renal artery and the aorta (RAR), the ratio of the peak velocities in the renal artery and the segmental artery (RSR), and the ratio of the peak velocities in the renal artery and the interlobar artery (RIR). All enrolled patients were divided into two groups based on the degree of diameter reduction: a severe stenosis group (diameter reduction ≥70%) and a non-severe stenosis group (diameter reduction <70%). Logistic regression analysis was performed to determine the independent predictors for severe stenosis. Receiver operating characteristic curves and areas under the curve were used to evaluate the diagnostic performance of the ultrasound Doppler parameters.

Results

A total of 85 patients (106 renal arteries) with RAS were included in this study. The optimal thresholds of PSV in the main renal artery and the PSV ratios for diagnosing severe RAS obtained via receiver operating characteristic curves were 249.5 cm/s for PSV, 2.94 for RAR, 5.1 for RSR, and 7.5 for RIR. The areas under the curve of PSV and the ratios all exhibited good diagnostic efficiency (all >0.8). The combination of these four Doppler variables demonstrated a significant benefit to the overall diagnostic value compared with any factor alone [area under the curve (AUC) =0.962; 95% confidence interval (CI): 0.906-0.989; P<0.05]. The combination of PSV and RSR (AUC =0.925; 95% CI: 0.858-0.967) exhibited comparable diagnostic efficiency to the combination of four ultrasonographic variables (z statistic =1.882; P=0.06).

Conclusions

This simple and accurate method to evaluate severe RAS based on the velocity obtained via basic DUS may facilitate the detection of severe RAS in the majority of medical institutions and provide a reliable basis for the selection of proper candidates for further angiography or revascularization.

Does Renal Denervation a Reasonable Treatment Option in Hemodialysis-Dependent Patient with Resistant Hypertension? A Narrative Review

PURPOSE OF REVIEW

This narrative review aims to assess the pathophysiology, diagnosis, and treatment of resistant hypertension (RH) in end-stage kidney disease (ESKD) patients on dialysis, with a specific focus on the effect of renal denervation (RDN) on short-term and long-term blood pressure (BP) control. Additionally, we share our experience with the use of RDN in an amyloidotic patient undergoing hemodialysis with RH.

RECENT FINDINGS

High BP, an important modifiable cardiovascular risk factor, is often observed in patients in ESKD, despite the administration of multiple antihypertensive medications. However, in clinical practice, it remains challenging to identify RH patients on dialysis treatment because of the absence of specific definition for RH in this context. Moreover, the use of invasive approaches, such as RDN, to treat RH is limited by the exclusion of patients with reduced renal function (eGFR < 45 mL/min/1.73 m3) in the clinical trials. Nevertheless, recent studies have reported encouraging results regarding the effectiveness of RDN in stage 3 and 4 chronic kidney disease (CKD) and ESKD patients on dialysis, with reductions in BP of nearly up to 10 mmhg. Although multiple underlying pathophysiological mechanisms contribute to RH, the overactivation of the sympathetic nervous system in ESKD patients on dialysis plays a crucial role. The diagnosis of RH requires both confirmation of adherence to antihypertensive therapy and the presence of uncontrolled BP values by ambulatory BP monitoring or home BP monitoring. Treatment involves a combination of nonpharmacological approaches (such as dry weight reduction, sodium restriction, dialysate sodium concentration reduction, and exercise) and pharmacological treatments. A promising approach for managing of RH is based on catheter-based RDN, through radiofrequency, ultrasound, or alcohol infusion, directly targeting on sympathetic overactivity.

Psychosocial determinants of healthcare use costs in kidney transplant recipients

Introduction

Psychosocial factors frequently occur in kidney transplant recipients (KTRs), leading to behavioral alterations and reduced therapeutic adherence. However, the burden of psychosocial disorders on costs for KTRs is unknown. The aim of the study is to identify predictors of healthcare costs due to hospital admissions and emergency department access in KTRs.

Methods

This is a longitudinal observational study conducted on KTRs aged >18 years, excluding patients with an insufficient level of autonomy and cognitive disorder. KTRs underwent psychosocial assessment via two interviews, namely the Mini-International Neuropsychiatric Interview 6.0 (MINI 6.0) and the Diagnostic Criteria for Psychosomatic Research Interview (DCPR) and via the Edmonton Symptom Assessment System Revised (ESAS-R) scale, a self-administrated questionnaire. Sociodemographic data and healthcare costs for hospital admissions and emergency department access were collected in the 2016-2021 period. Psychosocial determinants were as follows: (1) ESAS-R psychological and physical score; (2) symptomatic clusters determined by DCPR (illness behavior cluster, somatization cluster, and personological cluster); and (3) ICD diagnosis of adjustment disorder, anxiety disorder, and mood disorder. A multivariate regression model was used to test the association between psychosocial determinants and total healthcare costs.

Results

A total of 134 KTRs were enrolled, of whom 90 (67%) were men with a mean age of 56 years. A preliminary analysis of healthcare costs highlighted that higher healthcare costs are correlated with worse outcomes and death (p < 0.001). Somatization clusters (p = 0.020) and mood disorder (p < 0.001) were positively associated with costs due to total healthcare costs.

Conclusions

This study showed somatization and mood disorders could predict costs for hospital admissions and emergency department access and be possible risk factors for poor outcomes, including death, in KTRs.

The Impact of Cholecaciferol Supplementation on Bone Mineral Density in Long-Term Kidney Transplant Recipients

Although reduced bone mineral density (BMD) is associated with a higher risk of fractures, morbidity, and mortality in kidney transplant patients (KTRs), there is no consensus on optimal treatment for the alterations of BMD in this population. This study aims at assessing the effect of cholecalciferol supplementation on BMD over a follow-up period of 2 years in a cohort of long-term KTRs. Patients with age ≥ 18 years were included and divided into two subgroups based on treatment with bisphosphonate and/or calcimimetics and/or active vitamin D sterols (KTRs-treated) or never treated with the above medications (KTRs-free). BMD was evaluated at lumbar vertebral bodies (LV) and right femoral neck (FN) with standard DEXA at the beginning and end of the study. According to World Health Organization (WHO) criteria, results were expressed as T-score and Z-score. Osteoporosis and osteopenia were defined as T score ≤ −2.5 SD and T score < −1 and >−2.5 SD, respectively. Cholecalciferol was supplemented at a dose of 25,000 IU/week over 12 weeks followed by 1500 IU/day. KTRs-free (n. 69) and KTRs-treated (n. 49) consecutive outpatients entered the study. KTRs-free were younger (p < 0.05), with a lower prevalence of diabetes (p < 0.05) and of osteopenia at FN (46.3 % vs. 61.2 %) compared to KTRs-treated. At the entry none of the study subjects had a sufficient level of cholecalciferol; Z-score and T-score at LV and FN were not different between groups. At the end of the study period, serum cholecalciferol concentration was significantly increased in both groups (p < 0.001); the KTRs-free group presented an improvement in both T-score and Z-score at LV (p < 0.05) as well as a lower prevalence of osteoporotic cases (21.7% vs. 15.9%); in contrast, no changes were recorded in KTR-treated individuals. In conclusion, supplementation with cholecalciferol ameliorated Z-score and T-score at LV in long-term KTRs who had been never treated with active or inactive vitamin D sterols, bisphosphonates, and calcimimetics. Future endeavours are needed to confirm these preliminary findings.