Risk and complications of venous thromboembolism in dialysis patients

Background

Contemporary data on venous thromboembolism (VTE) risk in dialysis patients are limited. Our objective was to determine the risk and complications of VTE among incident maintenance dialysis patients.

Methods

We performed a retrospective cohort study using administrative databases. We included adult incident dialysis patients from 2004 to 2010 (n = 13 315). Dialysis patients were age- and sex-matched to individuals of the general population using a 1:4 ratio (n = 53 260). We determined the 3-year cumulative incidence and incidence rate (IR) of VTE, pulmonary embolism (PE) and deep venous thrombosis (DVT). We examined outcomes of bleeding and all-cause mortality following a VTE event among matched dialysis patients who did and did not experience a VTE. We used Cox proportional hazards regression models, stratified on matched sets, to calculate the hazard ratios (HRs) for all outcomes of interest.

Results

VTE occurred in 1114 (8.4%) dialysis patients compared with 1233 (2.3%) individuals in the general population {IR 37.1 versus 8.1 per 1000 person-years; HR 4.5 [95% confidence interval (CI) 4.1-4.9]; adjusted HR 2.9 (95% CI 2.6-3.4)}. Both components of VTE [PE and DVT; adjusted HR 4.0 (95% CI 2.9-5.6) and HR 2.8 (95% CI 2.4-3.2), respectively] occurred more frequently in dialysis patients. Compared with dialysis patients without a VTE, those with a VTE had a higher risk of bleeding [adjusted HR 2.0 (95% CI 1.3-2.9)] and all-cause mortality [adjusted HR 2.4 (95% CI 2.0-2.8)].

Conclusions

VTE is common in dialysis patients and confers a high risk of major bleeding and all-cause mortality. Thromboprophylaxis and VTE treatment studies in dialysis patients are needed.

Re-envisioning Fistula First in a patient-centered culture

The main options for vascular access in hemodialysis patients are arteriovenous fistulas (AVFs), arteriovenous grafts, and tunneled cuffed central venous catheters. AVFs have the lowest complication rate and require the fewest interventions and lowest cost to maintain. There has been a dramatic national increase in prevalent AVFs among patients with ESRD in the United States driven, in part, by the Fistula First Breakthrough Initiative. The Fistula First Breakthrough Initiative has engaged stakeholders in the dialysis community to disseminate best practices and quality improvement activities to increase AVF prevalence in suitable candidates. In the pursuit of maximizing AVF placement and prevalence, less emphasis has been placed on the individual patient context. An AVF may not be the best access choice in a subset of patients, particularly those with poor long-term prognoses or comorbid chronic diseases with a short life expectancy, those patients more likely to die than to have their CKD progress to ESRD requiring dialysis, and those with vascular anatomy not amenable to successful AVF placement. Placement of an AVF in these patients subjects them to uncomfortable and likely unnecessary and/or unsuccessful surgeries at an expense, while doing little to improve their clinical outcome or their individual experience of care. AVF prevalence as a pay-for-performance measure without the appropriate case-mix adjustment may penalize providers for accepting higher-risk patients. Although a functioning AVF that provides reliable hemodialysis remains the gold standard for vascular access for most patients, it may not be the most suitable option for every patient.

Confusion about the appropriate use of erythropoiesis-stimulating agents in patients undergoing maintenance dialysis

The introduction of recombinant erythropoietin for clinical use in dialysis patients in 1989 was considered a major milestone for the long-term treatment of these vulnerable patients. It was assumed that increasing hemoglobin concentrations would not only improve patient-reported outcomes, as shown in early trials, but also reduce morbidity and mortality. Evidence that has accumulated over the ensuing two decades has repeatedly contradicted this assumption. The presence of powerful stake holders, strong competing incentives, strong prior beliefs, and scarce and confusing evidence have maintained uncertainty about the appropriate treatment of patients with chronic kidney disease who are anemic, including those requiring dialysis. This commentary recalls the decades-long scientific and regulatory journey and attempts to make the case for the urgent need for potentially paradigm-shifting evidence generation to identify the therapeutic sweet spot that would maximize net benefits of treatment with erythropoiesis-stimulating agents in patients undergoing dialysis.

Cardiorenal syndrome type 4-cardiovascular disease in patients with chronic kidney disease: epidemiology, pathogenesis, and management

The term cardiorenal syndrome refers to the interaction between the heart and the kidney in disease and encompasses five distinct types according to the initial site affected and the acute or chronic nature of the injury. Type 4, or chronic renocardiac syndrome, involves the features of chronic renal disease (CKD) leading to cardiovascular injury. There is sufficient epidemiologic evidence linking CKD with increased cardiovascular morbidity and mortality. The underlying pathophysiology goes beyond the highly prevalent traditional cardiovascular risk burden affecting renal patients. It involves CKD-related factors, which lead to cardiac and vascular pathology, mainly left ventricular hypertrophy, myocardial fibrosis, and vascular calcification. Risk management should consider both traditional and CKD-related factors, while therapeutic interventions, apart from appearing underutilized, still await further confirmation from large trials.