Differences in coagulation between hemodialysis and peritoneal dialysis

Dialysis Modality and Incident Stroke Among Patients With End-Stage Kidney Disease: A Registry-Based Cohort Study

BACKGROUND

Patients with end-stage kidney disease undergoing dialysis are at significant risk of stroke. Whether dialysis modality is associated with cerebrovascular disease is unclear. This study compared the risk of incident stroke in patients undergoing peritoneal dialysis or hemodialysis.

METHODS

Thirty-nine thousand five hundred forty-two patients without a history of stroke who initiated dialysis between January 1, 2010, and December 31, 2014 were retrospectively studied using Taiwan's National Health Insurance Research Database. We matched 3809 patients undergoing peritoneal dialysis (mean age 59±13 years; 46.5% women) and 11 427 patients undergoing hemodialysis (mean age 59±13 years; 47.3% women) by propensity score in a 1:3 ratio with follow-up through December 31, 2015. The primary outcome was incident acute ischemic stroke. Secondary outcomes included hemorrhagic stroke, acute coronary syndrome, and all-cause mortality. Cox proportional hazard models were conducted to determine hazard ratios of clinical outcomes according to the dialysis modality.

RESULTS

During a median follow-up of 2.59 (interquartile range 1.50-3.93) years, acute ischemic stroke, hemorrhagic stroke, and acute coronary syndrome occurred in 783 (5.1%), 376 (2.5%), and 1350 (8.9%) patients, respectively. In a multivariable Cox model that accounted for the competing risk of death, acute ischemic stroke occurred more frequently in the peritoneal dialysis group than in the hemodialysis group (subdistribution hazard ratio, 1.32 [95% CI, 1.13-1.54]; P=0.0005). There were no significant treatment-related differences in the risk of hemorrhagic stroke (subdistribution hazard ratio, 0.89 [95% CI, 0.70-1.14]; P=0.3571) and acute coronary syndrome (subdistribution hazard ratio, 0.99 [95% CI, 0.88-1.12]; P=0.9080). Patients undergoing peritoneal dialysis were more likely to die from any cause than patients undergoing hemodialysis (adjusted hazard ratio, 1.24 [95% CI, 1.15-1.33]; P<0.0001).

CONCLUSIONS

Peritoneal dialysis was associated with a significantly increased risk of acute ischemic stroke compared with hemodialysis. Further studies are needed to clarify whether more aggressive cerebrovascular preventive strategies might mitigate the excess risk for ischemic stroke among patients receiving peritoneal dialysis.

Higher D-dimer and activated partial thromboplastin time are poor prognostic factors in patients with peritoneal dialysis-related peritonitis

INTRODUCTION

Coagulation system dysfunction is associated with adverse outcomes of peritoneal dialysis (PD) and bacterial infection. We investigated the association between coagulation system and treatment failure of peritoneal dialysis-related peritonitis (PDRP).

METHODS

We collected records of patients aged ≥18 years with PDRP. PDRP episodes were divided into: shortened activated partial thromboplastin time (APTT) group and prolonged APTT group, low D-dimer (DD) group and high DD group. The baseline characteristics of the groups were collected and compared. The association between APTT, DD and treatment failure of PDRP was analyzed using logistic regression analysis.

RESULTS

Thirty episodes of treatment failure were observed in 110 episodes of PDRP in our study. After adjusting for variables, prolonged APTT (OR = 1.166 [1.049-1.296], p = 0.004) or high level of DD (OR = 1.374 [1.057-1.787], p = 0.017) was associated with treatment failure of PDRP.

CONCLUSION

Prolonged baseline APTT or high level of DD increased the risk of treatment failure of PDRP.

Plasma fibrinogen: a driver of left ventricular remodeling in patients undergoing peritoneal dialysis and its related risk factors

BACKGROUND AND AIM

Plasma fibrinogen has been proven to be significantly associated with cardiovascular mortality in patients undergoing peritoneal dialysis (PD). The study aimed to investigate the role of fibrinogen in left ventricular (LV) remodeling and functions in patients on PD, and explore risk factors related to high fibrinogen level.

METHODS

From February 2008 to July 2018, adult patients on regular PD for at least 1 month were recruited and followed up for two years. Correlation analysis was performed to explore the fibrinogen level and echocardiography measurements. Pathogenic factors correlated to the left ventricular hypertrophy (LVH) progression were explored by logistic regression models and the role of fibrinogen in it was verified by receiver operating characteristic (ROC) curves. Linear regression models were conducted to identify factors associated with fibrinogen level.

RESULTS

A total of 278 patients undergoing PD (168 males, 60.4%) were recruited. Patients were trisected according to fibrinogen levels at baseline. Mean wall thickness (MWT), relative wall thickness (RWT), and left ventricular mass index (LVMI) were positively associated with fibrinogen level while E/A ratio was negatively associated with it. Multivariate logistic regression and ROC curve showed that fibrinogen was an independent risk factor for LVH progression. Multivariate linear regression analysis identified age, total cholesterol (CHO), fasting blood glucose (FBG), and high-sensitivity C-reactive protein (hsCRP) were significantly related to plasma fibrinogen level.

CONCLUSIONS

An elevated fibrinogen level was independently associated with LVH progression in patients undergoing PD. Older age, higher level of FBG, CHO, and hsCRP were risk factors for elevated plasma fibrinogen level.

Prognostic Significance of the Albumin to Fibrinogen Ratio in Peritoneal Dialysis Patients

Background

Albumin to fibrinogen ratio (AFR) is a demonstrated predictor of mortality in various diseases. The aim of this study was to evaluate the prognostic value of AFR to predict mortality in peritoneal dialysis (PD) patients.

Methods

We retrospectively analyzed 212 incident PD patients from January 2010 to December 2017 and followed them until December 2019. We used receiver operating curve (ROC) analysis to determine the optimal cut-off point for AFR at baseline to predict overall and cardiovascular mortality during the follow-up period. Kaplan-Meier curve and Cox regression analysis were applied to evaluate the association between AFR and all-cause and cardiovascular mortality.

Results

The optimal threshold for AFR to predict mortality was 8.48. A low AFR was strongly correlated with worse all-cause and cardiovascular mortality in PD patients. Multivariate analysis revealed that elevated AFR was an independent marker predicting reduced all-cause and cardiovascular mortality (HR 2.41, 95% CI 1.11–5.22, P = 0.026; and HR 2.18, 95% CI 1.21–3.95, P = 0.010, respectively).

Conclusions

Patients with a high AFR had reduced all-cause and cardiovascular mortality. AFR is a potential prognostic biomarker in PD patients.

Joint Deep-Learning-Enabled Impact of Holistic Care on Line Coagulation in Hemodialysis

In order to investigate the impact of holistic care on line coagulation and safety in hemodialysis and to address limitations of the conventional ultrasound flow vector imaging (VFM) technique, which requires proprietary software to acquire raw Doppler and scatter tracking data, a combined deep-learning-enabled holistic care approach to line coagulation in hemodialysis is proposed. First, velocity along the direction of the sound beam, which is provided by the color Doppler echocardiogram, is obtained as the radial velocity component using a velocity scale. Moreover, the left ventricular wall contour is automatically identified using a U-Net network and the left ventricular wall velocity is calculated as the boundary condition of continuity equation by a retrained PWC-Net model. Likewise, the velocity component of each blood mass in the vertical direction of the sound beam is obtained by solving the continuity equation (i.e. tangential velocity component). Finally, the velocity vector map of cardiac flow field was synthesized and visualized in the flow diagram. For this purpose, sixty patients admitted to receive hemodialysis from February 2019 to June 2020 were randomly divided into two groups of 30 patients where the control group implemented conventional care and the study group implemented all-round care on the basis of conventional care. The nursing effects of both groups were compared. Incidence of pipeline coagulation and complications in the study group were lower than those in the control group and the difference was statistically significant (P < 0.05). The nursing detail score, nursing attitude score, nursing professionalism score, and total satisfaction score in the study group were higher than those in the control group and the difference was statistically significant (P < 0.05). Applying all-round nursing in hemodialysis can effectively reduce the incidence of line coagulation complications and improve the safety of hemodialysis, as well as improve patients' satisfaction with nursing care.

Comparative analysis of therapeutic effects between medium cut-off and high flux dialyzers using metabolomics and proteomics: exploratory, prospective study in hemodialysis

In this single-center prospective study of 20 patients receiving maintenance hemodialysis (HD), we compared the therapeutic effects of medium cut-off (MCO) and high flux (HF) dialyzers using metabolomics and proteomics. A consecutive dialyzer membrane was used for 15-week study periods: 1st HF dialyzer, MCO dialyzer, 2nd HF dialyzer, for 5 weeks respectively. ¹H-nuclear magnetic resonance was used to identify the metabolites and liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis was used to identify proteins. To compare the effects of the HF and MCO dialyzers, orthogonal projection to latent structure discriminant analysis (OPLS-DA) was performed. OPLS-DA showed that metabolite characteristics could be significantly classified by 1st HF and MCO dialyzers. The Pre-HD metabolites with variable importance in projection scores ≥ 1.0 in both 1st HF versus MCO and MCO versus 2nd HF were succinate, glutamate, and histidine. The pre-HD levels of succinate and histidine were significantly lower, while those of glutamate were significantly higher in MCO period than in the HF period. OPLS-DA of the proteome also substantially separated 1st HF and MCO periods. Plasma pre-HD levels of fibronectin 1 were significantly higher, and those of complement component 4B and retinol-binding protein 4 were significantly lower in MCO than in the 1st HF period. Interestingly, as per Ingenuity Pathway Analysis, an increase in epithelial cell proliferation and a decrease in endothelial cell apoptosis occurred during the MCO period. Overall, our results suggest that the use of MCO dialyzers results in characteristic metabolomics and proteomics profiles during HD compared with HF dialyzers, which might be related to oxidative stress, insulin resistance, complement-coagulation axis, inflammation, and nutrition.

Fibrinogen Modification and Fibrin Formation in Patients with an End-Stage Renal Disease Subjected to Peritoneal Dialysis

End-stage renal disease (ESRD) is a condition accompanied by increased inflammation, oxidative stress, risk of cardiovascular complications, and coagulopathies. The structure of fibrinogen and characteristics of fibrin from plasma samples of ESRD patients on peritoneal dialysis (PD) was investigated. Fibrinogen from ESRD patients had a higher degree of carbonylation than fibrinogen from healthy individuals. The Aα chain was the most susceptible to oxidation, followed by the Bβ chain, whereas the γ-chain was the most resistant to oxidation. Spectrofluorimetric analysis suggested a higher extent of modification of amino acid side chains in fibrinogen from ESRD patients. The tertiary structure of fibrinogen was more affected than its secondary structure. The kinetics (time and rate) of fibrinogen coagulation did not differ between the tested groups. Fibrin prepared from the isolated fibrinogen had a similar structure in both groups. Our results confirm that oxidation and structural alterations of fibrinogen occur in ESRD patients on PD, although these modifications produce no direct effect on the fibrin formation. Taking into account that some patients suffer from bleeding, whereas others develop thrombotic complications, further research on this subject is required to identify other components and processes that contribute to the outcome.

Plasma fibrinogen and mortality in patients undergoing peritoneal dialysis: a prospective cohort study

BACKGROUND

Plasma fibrinogen is significantly associated with cardiovascular (CV) events and mortality in the general population. However, the association between plasma fibrinogen and mortality in patients undergoing peritoneal dialysis (PD) is unclear.

METHODS

This was a prospective cohort study. A total of 1603 incident PD patients from a single center in South China were followed for a median of 46.7 months. A Cox regression analysis was used to evaluate the independent association of plasma fibrinogen with CV and all-cause mortality. Models were adjusted for age, sex, smoking, a history of CV events, diabetes, body mass index, systolic blood pressure, hemoglobin, blood platelet count, serum potassium, serum albumin, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, hypersensitive C-reactive protein, estimated glomerular filtration rate, antiplatelet agents and lipid-lowering drugs.

RESULTS

The mean age was 47.4 ± 15.3 years, 955 (59.6%) patients were male, 319 (19.9%) had a history of CV events, and 410 (25.6%) had diabetes. The average plasma fibrinogen level was 4.12 ± 1.38 g/L. Of the 474 (29.6%) patients who died during follow-up, 235 (49.6%) died due to CV events. In multivariable models, the adjusted hazard ratios (HRs) for quartile 1, quartile 3, and quartile 4 versus quartile 2 were 1.18 (95% confidence interval [CI], 0.72-1.95, P = 0.51), 1.47 (95% CI, 0.93-2.33, P = 0.10), and 1.78 (95% CI, 1.15-2.77, P = 0.01) for CV mortality and 1.20 (95% CI, 0.86-1.68, P = 0.28), 1.29 (95% CI, 0.93-1.78, P = 0.13), and 1.53 (95% CI, 1.12-2.09, P = 0.007) for all-cause mortality, respectively. A nonlinear relationship between plasma fibrinogen and CV and all-cause mortality was observed.

CONCLUSIONS

An elevated plasma fibrinogen level was significantly associated with an increased risk of CV and all-cause mortality in patients undergoing PD.

Fibrinogen/Albumin ratio: A more powerful prognostic index for patients with end-stage renal disease

BACKGROUND

Microinflammation is linked to an increased risk of death due to cardiovascular disease (CVD) in patients with end-stage renal disease (ESRD). Although the fibrinogen/albumin ratio (FAR), a novel inflammatory marker, has been shown to predict mortality in various diseases, limited evidence is available for its role in ESRD. The purpose of this study is to explore the prognostic value of the FAR in ESRD patients on peritoneal dialysis (PD).

METHODS

In this retrospective observational study, we enrolled patients with ESRD who underwent PD therapy in our hospital between 1 January 2011 and 31 December 2017. The Kaplan-Meier method and Cox proportional hazards models were used to determine the contact between the FAR level and mortality.

RESULTS

A total of 562 patients were enrolled in our research. The median FAR was 0.12, and patients were divided into two groups (low FAR group: FAR < 0.12, n = 250, and high FAR group: FAR ≥ 0.12, n = 312) according to the median FAR. Kaplan-Meier curves showed that the cumulative incidences of both all-cause mortality and CVD mortality were significantly higher in patients with FAR ≥ 0.12 (both P < .001). In multivariable analysis, the high FAR group had an important increased risk of all-cause and CVD mortality (HR: 1.80; 95% CI: 1.03-3.14, P = .038 and HR: 2.31; 95% CI: 1.17-4.59, P = .016, respectively).

CONCLUSIONS

Our results suggest that a high baseline FAR value is an independent prognostic factor in ESRD patients on PD.

A synthetic heparin mimetic that allosterically inhibits factor XIa and reduces thrombosis in vivo without enhanced risk of bleeding

BACKGROUND

Human factor XIa (FXIa) is an actively pursued target for development of safer anticoagulants. Our long-standing hypothesis has been that allosterism originating from heparin-binding site(s) on coagulation enzymes is a promising approach to yield safer agents.

OBJECTIVES

To develop a synthetic heparin mimetic as an inhibitor of FXIa so as to reduce clot formation in vivo but not carry high bleeding risk.

METHODS

We employed a gamut of methods involving synthetic chemistry, biophysical biochemistry, enzyme assays, blood and plasma coagulation assays, and in vivo thrombosis models in this work.

RESULTS

Sulfated chiro-inositol (SCI), a non-saccharide mimetic of heparin, was synthesized in three steps in overall yields of >50%. SCI inhibited FXIa with potency of 280 nmol/L and preferentially engaged FXIa's heparin-binding site to conformationally alter its active site. SCI inhibition of FXIa could be rapidly reversed by common antidotes, such as protamine. SCI preferentially prolonged plasma clotting initiated with recalcification, rather than thromboplastin, alluding to its intrinsic pathway-based mechanism. Human blood thromboelastography indicated good ex vivo anticoagulation properties of SCI. Rat tail bleeding and maximum-dose-tolerated studies indicated that no major bleeding or toxicity concerns for SCI suggesting a potentially safer anticoagulation outcome. FeCl3 -induced arterial and thromboplastin-induced venous thrombosis model studies in the rat showed reduced thrombus formation by SCI at 250 μg/animal, which matched enoxaparin at 2500 μg/animal.

CONCLUSIONS

Overall, SCI is a highly promising, allosteric inhibitor of FXIa that induces potent anticoagulation in vivo. Further studies are necessary to assess SCI in animal models mimicking human clinical indications.

Serum lipoprotein(a) and risk of hemorrhagic stroke among incident peritoneal dialysis patients: a large study from a single center in China

Background: This retrospective study investigated whether baseline serum lipoprotein(a) (Lp(a)) may predict subsequent stroke in patients under chronic peritoneal dialysis (PD). Methods: Eight hundred and sixty incident PD patients, treated from 1 November 2005 to 28 February 2017, were enrolled, and followed until discontinuation of PD, death, or 31 May 2017. Hemorrhagic or ischemic stroke was the primary outcome. The population was stratified by baseline serum Lp(a) tertile. The risk of each stroke subtype was analyzed using the Cox proportional hazard models. Adjustments were made for: age; gender; history of stroke and hypertension; systolic blood pressure; lipid-lowering, antiplatelet and antihypertensive medications; laboratory profiles including hemoglobin, serum albumin, calcium, triglyceride, total and low-density lipoprotein cholesterol; and apolipoprotein A1. Results: Among the 860 participants, 19.3% and 4.1% had diabetes mellitus and a history of stroke, respectively. The median baseline serum Lp(a) was 328 (172-585) mg/L. After 28 (14-41) months of follow-up, 33 (3.84%) and 12 (1.40%) patients developed hemorrhagic and ischemic stroke, respectively. Participants in the highest Lp(a) tertile had a significantly lower risk of hemorrhagic stroke compared with those in the lowest tertile (hazard ratio (HR) 0.3, 95% confidence interval (CI) 0.1-0.86; p = .026); the rates of ischemic stroke were comparable among the tertiles. Each 10 mg/L rise in serum Lp(a) was associated with a 2% (95% CI 0.96-1; p = .033) lower risk of hemorrhagic stroke. Conclusions: Among patients with incident PD, a higher serum Lp(a) level may predict a lower risk of hemorrhagic stroke.

Evaluation of hemostasis in patients with end-stage renal disease

An increased bleeding risk is reported for patients with end-stage renal disease. This study aims to analyze, whether bleeding risk can be assessed by global tests of hemostasis. Standard laboratory tests and an extended evaluation of hemostasis by rotational thromboelastometry, platelet function analyzer (PFA) and multiple electrode aggregometry as well as thrombin generation assays and measurement of fibrinolytic potential were performed in 20 patients on hemodialysis, 10 patients on peritoneal dialysis, 10 patients with chronic kidney disease stage G5 (CKD5) and in 10 healthy controls (HC). Hemoglobin was significantly lower in patients with end-stage renal disease versus HC (each p<0.01). Patients on peritoneal dialysis showed increased fibrinogen levels compared to HC (p<0.01), which were also reflected by FIBTEM results (each p<0.05). 41% of hemodialysis patients and 44% of CKD5 patients presented with prolonged PFA-ADP-test (p<0.05), while no patient on peritoneal dialysis and no HC offered this modification. Thrombin generating potential was significantly lower in patients on hemodialysis, while clot lysis time revealed a hypofibrinolytic state in patients on hemo- and peritoneal dialysis compared to HC (p<0.001). In conclusion, patients with end-stage renal disease have complex hemostatic changes with both hyper- and hypocoagulable features, which are dependent on use and type of dialysis. Hypercoagulable features include elevated fibrinogen levels and a hypofibrinolytic state, whereas hypocoagulable features include decreased thrombin generating capacity and platelet dysfunction. Our results may contribute to a more rational approach to hemostatic management in these patients.

Unsupervised analysis of combined lipid and coagulation data reveals coagulopathy subtypes among dialysis patients

Hemodialysis (HD) and peritoneal dialysis (PD) are the primary means of managing end stage renal disease (ESRD). However, these treatment modalities are associated with the onset of coagulation abnormalities. Effective management of coagulation risk among these patients requires the identification of surrogate markers that provide an early indication of the coagulation abnormalities. The role of sphingolipids in the manifestation and prediction of coagulation abnormalities among dialysis patients have never been investigated. Herein, we report the first instance of an in depth investigation into the sphingolipid changes among ESRD patients undergoing HD and PD. The results reveal distinct differences in terms of perturbations to specific sphingolipid biosynthetic pathways that are highly dependent on the treatment modality. Our studies also demonstrated strong correlation between specific sphingolipids and coagulation parameters, such as HexCer(d18:1/26:0) and maximal amplitude (MA), SM(d18:1/24:1) and tissue factor pathway inhibitor, and sphingosine 1-phosphate d18:1 and FX (Spearman ρ of 0.93, 0.89, and -0.89, respectively). Furthermore, our study revealed the potential for using HexCer(d18:1/22:0), HexCer(d18:1/24:0), and HexCer(d18:1/26:0) (r² = 0.71, 0.82, and 0.63, respectively) and coagulation parameter MA (r² = 0.7) for successful diagnosis of differential coagulopathies among ESRD patients undergoing HD, providing an opportunity toward personalized disease management.

Differences in coagulation in clotting of vascular access in hemodialysis patients

Arteriovenous graft (AVG) thrombosis is a frequent cause of graft failure. We evaluated coagulation protein concentrations, platelet function, and viscoelasticity factors in 20 hemodialysis (HD) patients with AVGs. The goal was to determine whether significant differences in protein concentrations, platelet function, and viscoelasticity factors exist among dialysis patients requiring frequent AVG declot procedures vs. those who do not. Twenty HD patients were enrolled: 10 frequent clotters (>3 declots in the previous year) and 10 were nonclotters. Patients on antiplatelets or chronic anticoagulation were excluded. Laboratories were drawn pretreatment and heparinase was added to counteract any potential heparin effect. Coagulation protein concentrations including tissue factor (TF), thrombin/antithrombin III complex (TAT), and prothrombin fragment 1 + 2 (F(1+2)) were assayed. The time to clot onset was measured by force onset time (FOT). Platelet contractile force (PCF) measured the force produced by platelets during clot retraction, whereas clot rigidity was measured as clot elastic modulus (CEM). FOT, CEM, and PCF were measured by Hemodyne. Both groups had upregulation of the TF pathway, as TF, TAT, and F(1+2) levels were similarly increased over baseline levels. Hemodialysis patients with frequent AVG clotting had higher levels of both PCF and CEM compared with nonclotters. Additionally, the frequent clotters had a lower FOT relative to nonclotters, although both were considered in the normal range. Our study suggests that HD patients with recurrent AVG thrombotic events form clots with higher tensile strength compared with HD patients without recurrent graft thrombosis.