Risk of Venous Thromboembolism in Patients by Albuminuria and Estimated GFR

Kidney disease and stroke: epidemiology and potential mechanisms of susceptibility

Patients with chronic kidney disease (CKD) have an increased risk of both ischaemic and haemorrhagic stroke compared with the general population. Both acute and chronic kidney impairment are independently associated with poor outcome after the onset of a stroke, after adjustment for confounders. End-stage kidney disease (ESKD) is associated with a 7- and 9-fold increased incidence of both ischaemic and haemorrhagic strokes, respectively, poorer neurological outcome and a 3-fold higher mortality. Acute kidney injury (AKI) occurs in 12% of patients with stroke and is associated with a 4-fold increased mortality and unfavourable functional outcome. CKD patients seem to have less access to revascularisation techniques like thrombolysis and thrombectomy despite their poorer prognosis. Even if CKD patients could benefit from these specific treatments in acute ischaemic stroke, their prognosis remains poor. After thrombolysis, CKD is associated with a 40% increased risk of intracerebral haemorrhage (ICH), a 20% increase in mortality and poorer functional neurological outcomes. After thrombectomy, CKD is not associated with ICH but is still associated with increased mortality, and AKI with unfavourable outcome and mortality. The beneficial impact of gliflozins on the prevention of stroke is still uncertain. Non-traditional risk factors of stroke, like uraemic toxins, can lead to chronic cerebrovascular disease predisposing to stroke in CKD, notably through an increase in the blood-brain barrier permeability and impaired coagulation and thrombosis mechanisms. Preclinical and clinical studies are needed to specifically assess the impact of these non-traditional risk factors on stroke incidence and outcomes, aiming to optimize and identify potential therapeutic targets.

Association of the Urine-to-Plasma Urea Ratio With CKD Progression

RATIONALE & OBJECTIVES

The urine-to-plasma (U/P) ratio of urea is correlated with urine-concentrating capacity and associated with progression of autosomal dominant polycystic kidney disease. As a proposed biomarker of tubular function, we hypothesized that the U/P urea ratio would also be associated with progression of more common forms of chronic kidney disease (CKD).

STUDY DESIGN

Observational cohort study.

SETTING & PARTICIPANTS

3,723 adults in the United States with estimated glomerular filtration rate (eGFR) of 20-70 mL/min/1.73 m², enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study.

EXPOSURE

U/P urea ratio, calculated from 24-hour urine collections and plasma samples at baseline.

OUTCOME

Associations of U/P urea ratio with eGFR slope, initiation of kidney replacement therapy (KRT), and CKD progression, defined as 50% decline in eGFR or incident KRT.

ANALYTICAL APPROACH

Multivariable linear mixed-effects models tested associations with eGFR slope. Cox proportional hazards models tested associations with dichotomous CKD outcomes.

RESULTS

The median U/P urea ratio was 14.8 (IQR, 9.5-22.2). Compared with participants in the highest U/P urea ratio quintile, those in the lowest quintile had a greater eGFR decline by 1.06 mL/min/1.73 m² per year (P < 0.001) over 7.0 (IQR, 3.0-11.0) years of follow-up observation. Each 1-SD lower natural log-transformed U/P urea ratio was independently associated with CKD progression (HR, 1.22 [95% CI, 1.12-1.33]) and incident KRT (HR, 1.22 [95% CI, 1.10-1.33]). Associations differed by baseline eGFR (P interaction = 0.009). Among those with an eGFR ≥30 mL/min/1.73 m², each 1-SD lower in ln(U/P urea ratio) was independently associated with CKD progression (HR, 1.30 [95% CI, 1.18-1.45]), but this was not significant among those with eGFR <30 mL/min/1.73 m² (HR, 1.00 [95% CI, 0.84-1.20]).

LIMITATIONS

Possibility of residual confounding. Single baseline 24-hour urine collection for U/P urea ratio.

CONCLUSIONS

In a large and diverse cohort of patients with common forms of CKD, U/P urea was independently associated with disease progression and incident kidney failure. Associations were not significant among those with advanced CKD at baseline.

The association of venous thromboembolism with blood transfusion in kidney transplant patients

BACKGROUND

Red blood cell transfusion (RBCT) is common after kidney transplantation and could have pro-thrombotic effects predisposing to venous thromboembolism (VTE). The risks for developing of VTE after RBCT in kidney transplant patients are unknown.

STUDY DESIGN AND METHODS

This was a retrospective cohort study of adult kidney transplant recipients from 2002 to 2018. The exposure of interest was receipt of RBCT after transplant. Cox proportional hazards models were used to calculate hazard ratios (HR) for the outcomes of venous thromboembolism [VTE] (deep venous thrombosis [DVT] or pulmonary embolism [PE]) using RBCT as a time-varying, cumulative exposure.

RESULTS

Out of 1258 kidney transplants recipients, 468 (37%) were transfused during the study period. Seventy-nine study participants (6.3%) developed VTE, 72 DVT (5.7%), and 22 PE (1.8%). For the receipt of 1, 2, 3-5, and >5 RBCT, compared to individuals never transfused, the number of events and adjusted HR (95%CI) for VTE were 6 (6.2%) HR 1.57 (0.69-3.58), 9 (7.6%) HR 2.54 (1.30-4.96), 15 (11.9%) HR 2.73 (1.38-5.41), and 23 (18.1%) HR 5.77 (2.99-11.14) respectively; for DVT, it was 6 (6.2%) HR 1.94 (0.84-4.48), 9 (7.6%) HR 2.92 (1.44-5.94), 14 (11.1%) HR 3.29 (1.63-6.65), and 21 (16.5%) HR 6.97 (3.53-13.76), respectively. For PE, among transfused individuals, there were 14 events (3.0%) and the HR was 2.40 (1.02-5.61).

CONCLUSION

The risks for developing VTE, DVT, and PE were significantly increased in kidney transplant patients receiving RBCT after transplant. Receipt of RBCT should prompt considerations for judicious monitoring and assessment for thrombosis.

Proteinuria and venous thromboembolism in pregnancy: a population-based cohort study

Background

Pregnancy-associated venous thromboembolism (VTE) is associated with high morbidity and mortality. Identification of risk factors of VTE may lead to improved maternal and foetal outcomes. Proteinuria confers a pro-thrombotic state, however, its association with VTE in pregnancy remains unknown. We set out to assess the association of proteinuria and VTE during pregnancy.

Methods

We conducted a population-based, retrospective cohort study of all pregnant women (≥16 years of age) with a proteinuria measure within 20 weeks of conception (n = 306 244; mean age 29.8 years) from Ontario, Canada. Proteinuria was defined by any of the following: urine albumin:creatinine ratio ≥3 mg/mmol, urine protein:creatinine ratio ≥5 mg/mmol or urine dipstick proteinuria ≥1. The main outcome measure was a diagnosis of VTE up to 24-weeks post-partum.

Results

A positive proteinuria measurement occurred in 8508 (2.78%) women and was more common with a history of kidney disease, gestational or non-gestational diabetes mellitus and hypertension. VTE events occurred in 625 (0.20%) individuals, with a higher risk among women with positive proteinuria [32 events (0.38%)] compared with women without proteinuria [593 events (0.20%); inverse probability-weighted risk ratio 1.79 (95% confidence interval 1.25-2.57)]. The association was consistent using a more specific VTE definition, in the post-partum period, in high-risk subgroups (hypertension or diabetes) and when the sample was restricted to women with preserved kidney function.

Conclusions

The presence of proteinuria in the first 20 weeks of pregnancy is associated with a significantly higher risk of VTE.

Graft Function, Albuminuria, and the Risk of Hemorrhage and Thrombosis After Kidney Transplantation

Background:

Compared to the general population, kidney transplant recipients are at increased risk of hemorrhage and thrombosis. Whether this risk is affected by graft function and albuminuria is unknown.

Objective:

To determine the association between graft function and albuminuria and the risk of post-transplant hemorrhage and thrombosis.

Design:

Retrospective cohort study.

Setting:

We used linked health care databases in Alberta, Canada.

Patients/sample/participants:

We included adult kidney transplant recipients from 2002 to 2015 with a functioning graft at 1 year.

Measurements:

Estimated glomerular filtration rate (eGFR) and albuminuria measurements at 1 year post-transplant were used to categorize recipients (eGFR: ≥45 vs. <45 mL/min/1.73 m²; albuminuria: absence vs. presence). We determined the rates of post-transplant hemorrhage and venous thrombosis based on validated diagnostic and procedural codes.

Methods:

We determined the association between categories of eGFR and albuminuria and post-transplant hemorrhage and venous thrombosis using Poisson regression with log link.

Results:

Of 1284 kidney transplant recipients, 21% had an eGFR <45 mL/min/1.73 m² and 40% had presence of albuminuria at 1 year post-transplant. Over a median follow-up of 6 years, there were 100 hemorrhages (12.6 events per 1000 person-years) and 57 venous thrombosis events (7.1 events per 1000 person-years). The age- and sex-adjusted rate of hemorrhage and thrombosis was over 2-fold higher in recipients with lower eGFR and presence of albuminuria compared to higher eGFR and no albuminuria (hemorrhage: incidence rate ratio, IRR, 2.6, 95% confidence interval [CI]: 1.5-4.4, P = .001; thrombosis: IRR, 2.3, 95% CI: 1.1-5.0, P = .046).

Limitations:

Complete relevant medication information, such as anticoagulants, were not available in our datasets. Due to sample size, this study was underpowered to conduct a fully adjusted analysis.

Conclusion:

Among kidney transplant recipients, lower eGFR and presence of albuminuria at 1 year post-transplant were associated with an over 2-fold higher risk of hemorrhage and venous thrombosis. Graft function and albuminuria at 1 year post-transplant are important prognostic factors in determining risk of post-transplant hemorrhage and venous thrombosis. Further research, including medication data, are needed to further delineate outcomes and safety.

Trial registration:

Not applicable (cohort study).

Health risk of travel for chronic kidney disease patients

The number of people with chronic kidney disease (CKD) has increased and so has their demand for travel. However, the health risk posed by travel in these patients is unclear. Few reports document the travel risk in CKD and dialysis patients. The aim of this study is to summarize the existing evidence of the influence of travel on risks in CKD patients. We aim to describe the association between the impact of travel risks and patients with CKD. A detailed review of recent literature was performed by reviewing PubMed, Google Scholar, and Ichushi Web from the Japan Medical Abstracts Society. Screened involved the following keywords: “traveler's thrombosis,” “venous thromboembolism,” “deep vein thrombosis,” “altitude sickness,” “traveler's diarrhea,” “jet lag syndrome,” “melatonin,” with “chronic kidney disease” only, or/and “dialysis.” We present a narrative review summary of the literature from these screenings. The increased prevalence of thrombosis among travelers with CKD is related to a decrease in the estimated glomerular filtration rate and an increase in urine protein levels. CKD patients who remain at high altitudes are at an increased risk for progression of CKD, altitude sickness, and pulmonary edema. Traveler's diarrhea can become increasingly serious in patients with CKD because of decreased immunity. Microbial substitution colitis is also common in CKD patients. Moreover, time differences and disturbances in the circadian rhythm increase cardiovascular disease events for CKD patients. The existing literature shows that travel-related conditions pose an increased risk for patients with CKD.

Safety and Efficacy of Direct Oral Anticoagulants for Atrial Fibrillation in Patients with Renal Impairment

Direct oral anticoagulants (DOACs) are gaining popularity for patients with nonvalvular atrial fibrillation (AF) for stroke prevention. Less bleeding risk with comparable stroke prevention compared to warfarin was shown. DOACs have predictable anticoagulant effects, infrequent monitoring requirements and less drug-food interactions compared to warfarin. However, safety and efficacy data of DOACs in patients with chronic kidney disease (CKD) are limited. This is a retrospective study to evaluate thromboembolic and bleeding events in patients with AF (with/without CKD) in October 2010 and July 2017. A total of 495 patients were included and only 150 patients had CKD. Our study found that patients with renal impairment on a DOAC do not have a higher incidence of bleeding events. It showed significant increase in thromboembolic events in CKD patients with dabigatran compared to CKD patients with apixaban with odds ratio of 6.58 (95%CI 1.35-32.02, p = 0.02).

Thirty-year risk of ischemic stroke in individuals with sickle cell trait and modification by chronic kidney disease: The atherosclerosis risk in communities (ARIC) study

Sickle cell trait (SCT) has been associated with hypercoagulability, chronic kidney disease (CKD), and ischemic stroke. Whether concomitant CKD modifies long-term ischemic stroke risk in individuals with SCT is uncertain. We analyzed data from 3602 genotyped black adults (female = 62%, mean baseline age = 54 years) who were followed for a median 26 years by the Atherosclerosis Risk in Communities Study. Ischemic stroke was verified by physician review. Associations between SCT and ischemic stroke were analyzed using repeat-events Cox regression, adjusted for potential confounders. SCT was identified in 236 (7%) participants, who more often had CKD at baseline than noncarriers (18% vs 13%, P = .02). Among those with CKD, elevated factor VII activity was more prevalent with SCT genotype (36% vs 22%; P = .05). From 1987-2017, 555 ischemic strokes occurred in 436 individuals. The overall hazard ratio of ischemic stroke associated with SCT was 1.31 (95% CI: 0.95-1.80) and was stronger in participants with concomitant CKD (HR = 2.18; 95% CI: 1.16-4.12) than those without CKD (HR = 1.09; 95% CI: 0.74-1.61); P for interaction = .04. The hazard ratio of composite ischemic stroke and/or death associated with SCT was 1.20 (95% CI: 1.01-1.42) overall, 1.44 (95% CI: 1.002-2.07) among those with CKD, and 1.15 (95% CI: 0.94-1.39) among those without CKD; P for interaction = .18. The long-term risk of ischemic stroke associated with SCT relative to noncarrier genotype appears to be modified by concomitant CKD.

Anticoagulation in Patients With Advanced Chronic Kidney Disease: Walking the Fine Line Between Benefit and Harm

Chronic kidney disease affects more than 3 million Canadians and is highly associated with cardiovascular diseases that require anticoagulation, such as atrial fibrillation and venous thromboembolism. Patients with chronic kidney disease are at a problematic crossroads; they are at high risk of thrombotic conditions requiring anticoagulation and bleeding complications due to anticoagulation. The limited high-quality clinical evidence to guide decision-making in this area further compounds the dilemma. In this review, we discuss the physiology and epidemiology of bleeding and thrombosis in patients with kidney disease. We specifically focus on patients with advanced kidney disease (estimated glomerular filtration rate ≤ 30 mL/min) or who are receiving dialysis and focus on the nephrologist perspective regarding these issues. We summarize the existing evidence for anticoagulation use in the prevention of stroke with atrial fibrillation and provide practical clinical recommendations for considering anticoagulation use in this population. Last, we examine specific scenarios such as the use of a glomerular filtration rate estimating equation and dosing, the use of existing prediction tools for stroke and hemorrhage risk, current patterns of anticoagulation use (including during the dialysis procedure), and vascular calcification with vitamin K antagonist use in patients with chronic kidney disease.

Venous Thromboembolism Prophylaxis and Risk for Acutely Medically Ill Patients Stratified by Different Ages and Renal Disease Status

The objectives of this study were to examine venous thromboembolism (VTE) prophylaxis patterns and risk for VTE events during hospitalization and in the outpatient continuum of care among patients hospitalized for acute illnesses in the United States with stratification by different age groups and renal disease status. Acutely ill hospitalized patients were identified from the MarketScan databases (January 1, 2012-June 30, 2015) and grouped by age (<65, 65-74, ≥75 years old) and whether or not they had a baseline diagnosis of renal disease, separately. Of acutely ill hospitalized patients, 60.1% (n = 10 748) were <65 years old, 15.7% (n = 2803) were 65 to 74 years old, and 24.3% (n = 4344) were ≥75 years old; 32.9% (n = 5892) had baseline renal disease. Among the study cohorts, the majority of patients received no VTE prophylaxis regardless of age or baseline renal status (52.1%-63.6%). Rates of VTE during hospitalization and in the 6 months postdischarge were 4.7%, 4.6%, and 4.5% for patients <65, 65 to 74, and ≥75 years old, respectively, and 6.3% and 3.8% for patients with and without baseline renal disease. The risk for VTE was elevated for 30 to 40 days after index admission regardless of age and renal disease status.

Glomerular Filtration Rate as a Prognostic Factor for Long-Term Mortality after Acute Pulmonary Embolism

BACKGROUND

In-hospital mortality for patients presenting with acute pulmonary embolism (PE) has been reported to be up to 7 times higher for patients with decreased estimated glomerular filtration rate (eGFR). However, few studies have assessed its effect on long-term mortality.

OBJECTIVE

To determine the impact of eGFR and creatinine clearance (CrCl) on long-term all-cause mortality following acute PE in association with other routine laboratory analyses and comorbidities.

PATIENTS/METHODS

The prospective study enrolled 141 consecutive patients presenting with objectively confirmed acute PE. Demographic, clinical data, comorbidities, and laboratory values were recorded. CrCl and GFR were estimated using the Cockcroft-Gault, MDRD, and chronic kidney disease (CKD)-EPI equations. Patients were followed up at 90 days and 1 year after the event.

RESULTS

In univariate analyses, age, active cancer, PE severity index (PESI), CrCl and eGFR, D-dimer value, and high-density lipoprotein level were found to be significantly associated with mortality in 90 days and 1 year. Additionally, body mass index was significant in the 1-year follow-up. CrCl by Cockcroft-Gault (90-day: area under the curve [AUC] 0.763; 1-year: AUC 0.718) demonstrated higher discriminatory power for predicting mortality than eGFR by the MDRD (AUC 0.686; AUC 0.609) and CKD-EPI (AUC 0.697; AUC 0.630) equations. In multivariate analyses, active cancer, CrCl by Cockcroft-Gault (90-day: hazard ratio [HR] 0.948, 95% CI 0.919-0.979; 1-year: HR 0.967, 95% CI 0.943-0.991), eGFR by CKD-EPI (90-day: HR 0.948, 95% CI 0.915-0.983; 1-year: HR 0.971, 95% CI 0.945-0.998) were found to be independent predictors of mortality. eGFR by MDRD, D-dimer, and PESI value were significant prognostic factors for 90-day mortality.

CONCLUSION

Decreased renal function is a prognostic factor for increased all-cause mortality 90 days and 1 year after acute PE.

Novel oral anticoagulants in chronic kidney disease: ready for prime time?

PURPOSE OF REVIEW

Patients with chronic kidney disease (CKD) are at increased risk of atrial fibrillation, stroke, and bleeding posing unique clinical challenges. Novel oral anticoagulants (NOACs) including dabigatran, rivaroxaban, and apixaban have become recognized as alternative therapy to Vitamin K Antagonists (VKA) regarding the prevention of venous thromboembolism (VTE) and reduce the risk of stroke in atrial fibrillation. However, the understanding of NOACs in CKD is still underdeveloped. This review summarizes recent literature on the efficacy and safety of NOACs in patients with CKD.

RECENT FINDINGS

Studies focusing on patients with moderate kidney disease were drawn from post hoc analyses from three major NOAC trials, meta-analyses, and postmarketing surveillance studies. Cumulatively, these studies continue to demonstrate NOACs as equivalent if not superior therapies to VKAs in regards to both efficacy and safety. These studies are limited by small sample sizes as well as a lack of direct comparison between NOACs.

SUMMARY

The role of NOACs in managing VTE and atrial fibrillation is increasing. Current research suggests that NOACs are at least as efficacious and well tolerated as VKAs. More research is required to elucidate which NOAC is preferable in the clinical setting.