Management of dabigatran-induced bleeding: expert statement

Association between platelet count and the risk of bleeding among patients with nonvalvular atrial fibrillation taking dabigatran after radiofrequency ablation: a cohort study

Background

A reduction in platelet count or function can be a risk factor for bleeding in anticoagulated patients. However, the association between platelet count and the risk of bleeding among nonvalvular atrial fibrillation (NVAF) patients taking dabigatran remains unclear. The aim of this study was to investigate the relationship between platelet count and the risk of bleeding among patients with NVAF taking dabigatran after radiofrequency ablation.

Methods

In this multicenter, prospective and observational study, a total of 576 NVAF patients treated with dabigatran (110 mg bid) after radiofrequency ablation were recruited from 12 centers in China from February 2015 to December 2017. All patients were followed for 3 months. The association between platelet count and the risk of bleeding was evaluated by Cox proportional hazards regression analysis. To explore the nonlinearity between platelet count and bleeding, we used a Cox proportional hazards regression model with cubic spline functions and smooth curve fitting and a two-piecewise Cox proportional hazards model.

Results

During a median follow-up duration of 87 days, 50 patients experienced bleeding events. Overall, there was an inverse relationship between the risk of bleeding and platelet count. Low platelet count (<100×10⁹/L) were associated with an increased risk of bleeding [hazard ratio (HR), 4.05; 95% confidence interval (CI): 1.32-12.46] compared to normal counts. The adjusted smooth curve showed a nonlinear relationship between platelet count and bleeding events. The inflection point of the platelet count was 105×10⁹/L. For platelet counts <105×10⁹/L, the HR (95% CI) was 0.89 (0.84-0.95), and for platelet counts ≥105×10⁹/L, the HR (95% CI) was 1.01 (0.95-1.08).

Conclusions

Low platelet counts were associated with an increased risk for bleeding among patients with NVAF taking dabigatran after catheter ablation.

Association Between the Change in Total Bilirubin and Risk of Bleeding Among Patients With Nonvalvular Atrial Fibrillation Taking Dabigatran

There is still a lack of effective biomarkers for the prediction of the risk of bleeding events among patients with nonvalvular atrial fibrillation (NVAF) taking dabigatran. This study aimed to investigate the association between change in total bilirubin (CTBIL) and risk of bleeding among patients with NVAF taking dabigatran. The CTBIL was the difference in serum total bilirubin at out of follow-up from baseline serum total bilirubin. A total of 486 patients with NVAF treated with dabigatran (110 mg twice daily) were recruited from 12 centers in China from February 2015 to December 2017. All patients were followed for 3 months. Cox proportional hazards regression analysis was used to evaluate the association between the CTBIL and bleeding. Moreover, a Cox proportional hazards regression with cubic spline functions and smooth curve fitting (the penalized spline method) and 2 piecewise Cox proportional hazards models were used to address the nonlinearity between CTBIL and bleeding. The mean (SD) follow-up duration was 81.2 (20.2) days. In all, 67 patients experienced bleeding events. A U-shaped association was observed between the CTBIL and bleeding, with increased hazard ratios (HRs) in relation to either low or high CTBIL levels. For CTBIL <6.63 µmol/L, the HR (95% confidence interval [CI]) was 0.90 (0.84-0.96), and for CTBIL ≥6.63 µmol/L, the HR (95% CI) was 1.35 (1.14-1.60). Our findings showed a U-shaped relationship between CTBIL and bleeding. Both low and high levels of CTBIL were associated with a higher risk of bleeding.

Emergency care of patients receiving non-vitamin K antagonist oral anticoagulants

Non-vitamin K antagonist oral anticoagulants (NOACs), which inhibit thrombin (dabigatran) and factor Xa (rivaroxaban, apixaban, edoxaban) have been introduced in several clinical indications. Although NOACs have a favourable benefit-risk profile and can be used without routine laboratory monitoring, they are associated-as any anticoagulant-with a risk of bleeding. In addition, treatment may need to be interrupted in patients who need surgery or other procedures. The objective of this article, developed by a multidisciplinary panel of experts in thrombosis and haemostasis, is to provide an update on the management of NOAC-treated patients who experience a bleeding episode or require an urgent procedure. Recent advances in the development of targeted reversal agents are expected to help streamline the management of NOAC-treated patients in whom rapid reversal of anticoagulation is required.

[Consensus statement: Stroke prevention in nonvalvular atrial fibrillation in special consideration of the new direct oral anticoagulants]

The introduction of new direct oral anticoagulants has changed the treatment of nonvalvular atrial fibrillation. However, these changes are not yet fully reflected in current guidelines.This consensus statement, endorsed by six Austrian medical societies, provides guidance to current prophylactic approaches of thromboembolic events in nonvalvular atrial fibrillation on the basis of current evidence and published guidelines. Furthermore, some special subjects are treated, like changes in laboratory parameters and their interpretation under treatment with direct oral anticoagulants, treatment of bleedings, approach to operations, cardioversion and ablation, and specific neurological aspects. For a CHA2DS2-VASc-Score of ≥ 2, anticoagulation is recommended with a high level of evidence (1A). At the end of the consensus statement, recommendations for a number of specific patient subgroups can be found, in order to help treating physicians to arrive at appropriate therapeutic decisions.

[Prevention of venous thromboembolism in musculoskeletal surgery]

Musculoskeletal surgery is associated with a high risk of venous thrombosis and pulmonary embolism. The introduction of direct oral anticoagulants (DOAK) has broadened the possibilities for prevention of venous thromboembolism in the course of orthopedic and trauma surgery. Addressing this recent development, the Austrian Societies of Orthopedics and Orthopedic Surgery (ÖGO), Trauma Surgery (ÖGU), Hematology and Oncology (OeGHO) and of Anaesthesiology, Reanimation und Intensive Care Medicine (ÖGARI) have taken the initiative to create Austrian guidelines for the prevention of thromboembolism after total hip and knee replacement, hip fracture surgery, interventions at the spine and cases of minor orthopedic and traumatic surgery. Furthermore, the pharmacology of the DOAK and the pivotal trial data for each of the three currently available substances - apixaban, dabigatran, and rivaroxaban - are briefly presented. Separate chapters are dedicated to "anticoagulation and neuroaxial anesthesia" and "bridging".

Perioperative management issues of direct oral anticoagulants

The treatment repertoire of oral anticoagulation has changed dramatically over the past few years from one class of vitamin K1 antagonists to an increasing number of direct oral anticoagulants (DOACs). Clinicians are confronted with the problem of managing patients on novel agents in the critical setting before, during, and after surgery, where the risk of bleeding and thrombosis are increased simultaneously. Randomized clinical data are insufficient to date, but clinical exposure enlarges the body of experience. The following review considers perioperative management issues in various categories, including minor elective surgery, major elective surgery, and acute surgery. This review is a credo to personalized medicine where the patient's underlying thromboembolic risk status, the potential bleeding risk, or actual hemorrhagic manifestation determine the selection of multi-modal targeted management strategies.