Peripheral vascular disease-related procedures in dialysis patients: predictors and prognosis

Phosphorus Content of Commonly Prescribed Medications Among Patients With Chronic Kidney Disease

OBJECTIVES

This study aimed to build a brand-specific library of phosphorus content in medications and to determine the median daily phosphorus intake from medications among chronic kidney disease (CKD) patients in Singapore.

METHODS

This is a single-center, cross-sectional study conducted in 200 patients with CKD Stages 3-5D. Package inserts of medications commonly used by the CKD patients were reviewed to identify brands containing phosphorus. Drug manufacturers were contacted to obtain phosphorus content of products. The median daily phosphorus intake from medications of the 200 patients was then calculated using the information.

RESULTS

A total of 399 formulations of 204 medications and supplements were reviewed (March 2020). Fifty-eight (15%) formulations were found to contain phosphorus. Forty-three (11%) formulations had missing information regarding the phosphorus content. Based on available information, the median daily phosphorus intake from medications was 1.28 mg (interquartile range = 0.006-16.08) across the CKD stages. Patients with CKD Stage 5D had a higher median intake of 4.09 mg (P = .009). A dose-independent variation in phosphorus content of excipients between generic and branded formulations was noted in this study. We have developed a library of phosphorus content in medications.

CONCLUSIONS

The inorganic phosphorous content in frequently prescribed medications for CKD patients is generally low, with excipients (as opposed to the active ingredient or counterions) being the main source of phosphorus. Although this may seem almost negligible in comparison to the recommended dietary intake, prescribers should still exercise care, given the wide range of phosphorus content possible between different brands of the same medication, and the unpredictable absorption of inorganic phosphate in CKD patients.

Characteristics of patients at initiation of renal replacement therapy - experience of a hemodialysis center

The monitoring and care of patients with chronic kidney disease (CKD) before the dialysis initiation contribute to a better survival rate and an improvement in quality of life. The patients who do not benefit from a good predialysis management have a worse short and long-term prognosis. A retrospective, unicentric study was performed to evaluate the status of patients with stage 5 CKD at the time of initiation of renal replacement treatment. A total of 109 patients were included in the study. The evaluation of the patients included the clinical manifestations leading to hemodialysis initiation, the clinical and laboratory data of the patients when the hemodialysis was started. Based on the obtained data, a statistical analysis was performed using the Chi-square test, Fisher's exact test, ANOVA, and Kruskal-Wallis H test. The mean age of the patients was 64.61±13.59 years. Of the patients 51.38% were women. Vascular nephropathies and diabetes mellitus dominated the etiology of CKD. The comorbidities were high blood pressure, ischemic heart disease, history of myocardial infarction, heart failure, history of stroke, peripheral artery disease or atrial fibrillation. Only 43 (39.45%) of our patients were monitored before the hemodialysis initiation. Hemodialysis was initiated on central venous catheter (in most cases non-tunneled) in 78.90% of the patients. Most of the patients had an altered general status, fatigue/tiredness with poor exercise capacity when hemodialysis was initiated. Most of the patients (98.17%) had anemia, the average level of hemoglobin being 8.69±1.85 g/dl. In conclusion, careful monitoring of patients in the early stages of CKD would result in lower morbidity and mortality. These objectives can be achieved by implementing screening programs and early interventions.

Drug-Coated Balloon vs. Conventional Balloon Angioplasty in Dialysis Patients With Symptomatic Femoropopliteal Disease - A Matched Comparison

BACKGROUND

Recent randomized trials have shown the treatment benefits of use of a drug-coated balloon (DCB) over conventional percutaneous transluminal angioplasty (PTA) in patients with femoropopliteal disease. However, the effectiveness and safety of DCB for dialysis patients remain unclear.Methods and Results:Consecutive dialysis patients, who underwent PTA or DCB for femoropopliteal disease, were assessed retrospectively via 2:1 propensity score matching. Effectiveness and safety endpoints, including binary restenosis, clinically driven target lesion revascularization (CD-TLR), amputations, major adverse cardiac events (MACE), and deaths, were compared between groups. A total of 278 dialysis patients with 339 limbs were eligible for matching: 84 limbs from 77 patients treated with PTA and 46 limbs from 37 patients treated with DCB were compared after matching. Baseline patient and lesion characteristics were not different between groups. Patients treated with DCB had significantly higher rates of freedom from binary restenosis (52.4% vs. 18.6%, P<0.001) and CD-TLR (56.4% vs. 25.9%, P=0.001) at 2 years compared with patients treated with PTA. Both groups had similar outcomes for amputation, MACE, and death. Cox proportional analysis showed that treatment with DCB was independently associated with a reduction of binary restenosis (hazard ratio [HR] 0.368, P=0.001) and CD-TLR (HR 0.390, P=0.004).

CONCLUSIONS

This study suggested superior 2-year outcomes using DCB compared with PTA and similar safety profiles in dialysis patients with femoropopliteal disease.

Prevalence and Risk Factors of Lower Limb Amputation in Patients with End-Stage Renal Failure on Dialysis: A Systematic Review

Background. Renal dialysis has recently been recognised as a risk factor for lower limb amputation (LLA). However, exact rates and associated risk factors for the LLA are incompletely understood. Aim. Prevalence and risk factors of LLA in end-stage renal failure (ESRF) subjects on renal dialysis were investigated from the existing literature. Methods. Published data on the subject were derived from MEDLINE, PubMed, and Google Scholar search of English language literature from January 1, 1980, to July 31, 2015, using designated key words. Results. Seventy studies were identified out of which 6 full-text published studies were included in this systematic review of which 5 included patients on haemodialysis alone and one included patients on both haemodialysis and peritoneal dialysis. The reported findings on prevalence of amputation in the renal failure on dialysis cohort ranged from 1.7% to 13.4%. Five out of the six studies identified diabetes as the leading risk factor for amputation in subjects with ESRF on renal dialysis. Other risk factors identified were high haemoglobin A1c, elevated c-reactive protein, and low serum albumin. Conclusions. This review demonstrates high rate of LLA in ESRF patients receiving dialysis therapy. It has also identified diabetes and markers of inflammation as risk factors of amputation in ESRF subjects on dialysis.

Non-traumatic lower limb amputation in patients with end-stage renal failure on dialysis: an Australian perspective

BACKGROUND

End-stage renal failure (ESRF) and dialysis have been identified as a risk factor for lower limb amputations (LLAs). High rate of ESRF amongst the Australian population has been reported, however till date no study has been published identifying magnitude and risk factors of LLA in subjects on renal dialysis.

OBJECTIVE

The study aims to document trends in the prevalence and identify risk factors of non-traumatic LLA in Australian patients on dialysis.

METHODS

A retrospective review of all patients (218) who attended the regional dialysis center between 1st January 2009 and 31st December 2013 was conducted. Demographic, clinical and biochemical data were analyzed.

RESULTS

We identified a high prevalence of 13.3% of LLAs amongst Australian patients with ESRF on dialysis at our center. The associated risk factors were the presence of diabetes (OR 1.67 [1.49-1.88] p < 0.001), history of foot ulceration (OR 81 [18.20-360.48] p < 0.001), peripheral arterial disease (OR 31.29 [9.02-108.56] p < 0.001), peripheral neuropathy (OR 31.29 [9.02-108.56] p < 0.001), foot deformity (OR 23.62 [5.82-95.93] p < 0.001), retinopathy (OR 6.08 [2.64-14.02] p < 0.001), dyslipidemia (OR 4.6 [1.05-20.05] p= 0.049) and indigenous background (OR 3.39 [1.38-8.33] p= 0.01). 75% of the amputees had aboriginal heritage. We also identified higher HbA1c and CRP levels as well as low serum albumin, hemoglobin and vitamin D levels to have a strong association with LLAs (p < 0.05).

CONCLUSION

There is high prevalence of LLAs amongst Australian indigenous patients with diabetes on dialysis in North Queensland. Other strongly associated risk factors include history of foot ulceration, foot deformity and peripheral neuropathy as well as high HbA1c levels and low serum albumin levels.

Assay development of inducible human renal phosphate transporter Npt2A (SLC34A1) in Flp-In-Trex-HEK293 cells

Hyperphosphatemia is associated with severe decline of renal function in chronic kidney disease and elevates cardiovascular mortality. Type II sodium dependent phosphate transporter 2A (Npt2A) plays a major role in renal phosphate reabsorption and could be explored as a target for anti-hyperphosphatemia therapy. Human Npt2A transporter activity was examined upon transfection into CHO, MDCK, HEK293, Flp-In-CHO and Flp-In-HEK293 cells. Only kidney-derived cells expressed functional Npt2A. HEK293 and Flp-In-HEK293 cell lines stably transfected with hNpt2A could be selected, but these cells were inactive in phosphate transport. This suggests that high-level, constitutive Npt2A expression has deleterious effects on the cell. By using the conditional promoter in the Flp-In-Trex vector, functional expression of Npt2A was achieved by doxycycline induction in HEK293 cells. The EGFP tagged and non-tagged, inducible stable hNpt2A-HEK293 cell lines afforded development of a robust phosphate uptake assay mediated by hNpt2A, which can be used to screen hNpt2A inhibitors and inducers of hNpt2A expression. Using this assay, the small molecule LC-1 was identified as a potent inhibitor of hNpt2A, suggesting that it is feasible to develop potent specific hNpt2A inhibitors to control phosphate overloading for hyperphosphatemia therapy.

Higher serum levels of soluble intracellular cell adhesion molecule-1 and soluble vascular cell adhesion molecule predict peripheral artery disease in haemodialysis patients

AIM

Serum levels of soluble intracellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM) and monocyte chemotactic protein 1 (MCP-1), are elevated in patients with peripheral artery disease (PAD). However, the levels of these cell adhesion molecules in patients undergoing haemodialysis (HD) are unclear.

METHOD

A total of 112 HD patients were included and PAD was diagnosed using the ankle-brachial index and Doppler ultrasound. Serum levels of sICAM-1, sVCAM-1 and MCP-1 were assayed using enzyme linked immunosorbent assay.

RESULTS

Out of 106 HD patients, 31 (27.7%) were diagnosed with PAD. After adjusting for risk factors, higher serum levels of sVCAM-1 and sICAM-1 were associated with PAD in HD patients, with an odds ratio of 5.3 (95% CI 3.3-65.5) and 2.7 (95% CI 1.2-21.8) respectively. Using sVCAM-1 and sICAM-1 for diagnosis of PAD in HD patients, sVCAM-1 had a sensitivity of 72.4% and specificity of 62.3% for sVCAM-1 and sICAM-1 had a sensitivity of 89.3% and a specificity of 40%. MCP-1 was not associated with PAD in HD patients. In addition, the fistula of HD patients with PAD had a lower A-V access flow.

CONCLUSION

sVCAM-1 and sICAM-1 was associated with higher risk of PAD in HD patients. Moreover, HD patients with PAD had a lower blood flow and lower A-V access flow. Our results showed that sVCAM-1 and sICAM-1 may be used as screening markers for PAD in HD patients.

Phosphate: a stealthier killer than previously thought?

The kidneys excrete excess dietary phosphate, and patients with chronic kidney disease may suffer from phosphate overload and hyperphosphatemia. In chronic kidney disease, hyperphosphatemia has emerged as a risk factor for vascular calcification, cardiovascular mortality, left ventricular hypertrophy, and progression of chronic kidney disease. Serum phosphate at the upper limits of normal has also been associated with adverse outcomes in patients with relatively preserved kidney function. Of note, hyperphosphatemia is not a sensitive indicator of phosphate overload. In this regard, increased circulating fibroblast growth factor-23, a phosphatonin that is released in response to phosphate overload, is independently associated with adverse outcomes in patients with and without chronic kidney disease. Direct effects of extracellular phosphate on vascular calcification or cardiovascular cell biology; adverse consequences of adaptive mechanisms activated to limit phosphate overload, such as left ventricular hypertrophy induced by fibroblast growth factor-23; or epidemiological associations of additional cardiovascular risk factors with chronic kidney disease may underlie these observations. We now review the pathophysiology of phosphate, its relationship with cardiovascular outcomes, the potential consequences for patient care related to dietary phosphate and phosphate binders, and the clinical relevance for patients without overt chronic kidney disease.

Soluble P-selectin levels are associated with cardiovascular mortality and sudden cardiac death in male dialysis patients

BACKGROUND/AIMS

P-selectin is released by activated platelets and endothelium contributing to inflammation and thrombosis. We evaluated the association between soluble P-selectin and atherosclerotic cardiovascular disease (ASCVD) in dialysis patients.

METHODS

We measured soluble P-selectin in serum from 824 incident dialysis patients. Using Cox proportional hazards models, we modeled the association of P-selectin levels with ASCVD events, cardiovascular mortality and sudden cardiac death.

RESULTS

After adjustment for demographics, comorbidity and traditional cardiovascular risk factors, higher P-selectin levels were associated with increased risk of ASCVD and cardiovascular mortality among males (p = 0.02 and p = 0.01, respectively), but not females (p = 0.52 and p = 0.31, respectively; p interaction = 0.003), over a median of 38.2 months. Higher P-selectin was associated with a greater risk of sudden cardiac death among males (p = 0.05). The associations between increasing P-selectin and cardiovascular mortality as well as sudden cardiac death in males persisted after adjustment for C-reactive protein, interleukin-6, serum albumin and platelet count (p = 0.01 and p = 0.03, respectively). The risk for sudden cardiac death was more than 3 times greater for males in the highest tertile of soluble P-selectin compared with the lowest tertile after adjustment (HR: 3.19; 95% CI: 1.18 - 8.62; p = 0.02).

CONCLUSION

P-selectin is associated with ASCVD, cardiovascular mortality and sudden cardiac death among male dialysis patients.