Association Between Low-Molecular-Weight Heparin and Risk of Bleeding Among Hemodialysis Patients: A Retrospective Cohort Study

Bleeding Risk in Hemodialysis Patients

Cardiovascular diseases are highly prevalent among patients on dialysis. For these diseases, antiplatelets and antithrombotic therapies including heparin, vitamin K antagonists, and direct oral anticoagulants, are being used. However, the benefit-risk balance of these therapies could differ for dialysis patients compared with the general population. This review article focuses on the bleeding risk associated with the use of heparin, antiplatelets, vitamin K antagonists, and direct oral anticoagulants in patients receiving hemodialysis.

Single-Bolus Tinzaparin Anticoagulation in Extended Hemodialysis Session: A Feasibility Study

Key Points

A single bolus of tinzaparin is effective for 8-hour hemodialysis session. Eight-hour simulation sessions with anti-Xa monitoring are useful to adjust tinzaparin dose.

Background

Few studies have assessed the use of low-molecular weight heparins for anticoagulation during extended hemodialysis (HD) sessions. This study aimed to evaluate the efficacy of a single bolus of tinzaparin for anticoagulation of the extracorporeal circuit and dialyzer in 8-hour HD sessions.

Methods

This single-center study included all patients who underwent a single 8-hour simulation session as part of their nocturnal home HD training between 2009 and 2020. Tinzaparin was delivered as a single-bolus injection at time 0 with dosing on the basis of doubling of standard 4-hour session dose. Tinzaparin efficacy was examined using visual observations (score 1–4) of the dialyzer and venous bubble trap at the end of dialysis and using anti-Xa measured at 15 and 30 minutes and 1, 2, 4, 6, and 8 hours after HD start.

Results

Forty-seven patients were included. The mean tinzaparin dose was 107±20 IU/kg. Anti-Xa levels peaked at 15 minutes with 1.3±0.4 IU/ml and progressively declined reaching 0.9±0.3 IU/ml at 1 hour, 0.4±0.21 IU/ml at 4 hours, and 0.15±0.15 IU/ml at 8 hours. After the 8-hour session, none of the patients had severe clotting of their dialyzer or venous chamber. Moderate blood clotting was observed in the dialyzer of 6 patients (20%) and in the venous chamber of 22 patients (61%). On the basis of the simulation results, tinzaparin dose was increased in 27 patients (58%) with a mean home-discharge dose of 123±28 IU/kg.

Conclusions

This study shows that anti-Xa levels stabilized rapidly after administration of tinzaparin for 8-hour HD. Administration of a single-bolus tinzaparin at the start of an 8-hour dialysis session seemed effective, although dose adjustment may be required.

Using dalteparin in quotidian and nocturnal hemodialysis patients: A prospective study

INTRODUCTION

Low-molecular weight heparin, such as dalteparin, is an alternative anticoagulation method in conventional hemodialysis (HD). However, there are limited studies on its use in quotidian and nocturnal HD. We assessed the optimal dose, treatment efficacy, and patient safety of dalteparin in quotidian and nocturnal HD populations.

METHODS

This study included 10 quotidian (7 in-center and 3 home) and 8 nocturnal home HD patients. Dalteparin was initiated and titrated based on clotting score in these patients. Trough anti-Xa levels were measured. The dalteparin dose, the dialyzer and HD circuit clotting scores, and bleeding episodes were recorded at 4 weeks. Patients who continued dalteparin were followed to 12 months.

FINDINGS

For the 10 quotidian HD patients, the median dalteparin dose was 1875 units [1250, 2500] after 4 weeks. For nocturnal HD patients, five of the eight patients switched back to heparin due to high clotting scores while on dalteparin within 4 weeks. However, three patients continued on dalteparin at 4 weeks. After 12 months, one maintained on 5000 units and the other two maintained on 7500 units of dalteparin. All the clotting scores at month 12 were ≤2. One patient died due to an unrelated cause. For all patients who continued on dalteparin, only 9% of the HD treatments had circuit clotting score >2 after reaching stable dose. All trough anti-Xa levels were <0.1 IU/mL. There were no episodes of bleeding. Fistula compression times were not increased.

DISCUSSION

This small pilot study suggests that dalteparin can be used effectively and relatively safety in quotidian HD. However, its use in nocturnal HD was only successful in a small proportion of patients. Alternative methods, including second dalteparin bolus after 4 hours of HD treatment, should be assessed for efficacy and practicality.