Evaluation of anticoagulation selection for acute venous thromboembolism

Antiplatelets and antithrombotics in neurointerventional procedures: Guideline update

BACKGROUND

Antiplatelet and antithrombotic medication management before, during, and after neurointerventional procedures has significant practice variation. This document updates and builds upon the 2014 Society of NeuroInterventional Surgery (SNIS) Guideline 'Platelet function inhibitor and platelet function testing in neurointerventional procedures', providing updates based on the treatment of specific pathologies and for patients with specific comorbidities.

METHODS

We performed a structured literature review of studies that have become available since the 2014 SNIS Guideline. We graded the quality of the evidence. Recommendations were arrived at through a consensus conference of the authors, then with additional input from the full SNIS Standards and Guidelines Committee and the SNIS Board of Directors.

RESULTS

The management of antiplatelet and antithrombotic agents before, during, and after endovascular neurointerventional procedures continues to evolve. The following recommendations were agreed on. (1) It is reasonable to resume anticoagulation after a neurointerventional procedure or major bleeding episode as soon as the thrombotic risk exceeds the bleeding risk in an individual patient (Class I, Level C-EO). (2) Platelet testing can be useful to guide local practice, and specific approaches to using the numbers demonstrate marked local variability (Class IIa, Level B-NR). (3) For patients without comorbidities undergoing brain aneurysm treatment, there are no additional considerations for medication choice beyond the thrombotic risks of the catheterization procedure and aneurysm treatment devices (Class IIa, Level B-NR). (4) For patients undergoing neurointerventional brain aneurysm treatment who have had cardiac stents placed within the last 6-12 months, dual antiplatelet therapy (DAPT) is recommended (Class I, Level B-NR). (5) For patients being evaluated for neurointeventional brain aneurysm treatment who had venous thrombosis more than 3 months prior, discontinuation of oral anticoagulation (OAC) or vitamin K antagonists should be considered as weighed against the risk of delaying aneurysm treatment. For venous thrombosis less than 3 months in the past, delay of the neurointerventional procedure should be considered. If this is not possible, see atrial fibrillation recommendations (Class IIb, Level C-LD). (6) For patients with atrial fibrillation receiving OAC and in need of a neurointerventional procedure, the duration of TAT (triple antiplatelet/anticoagulation therapy=OAC plus DAPT) should be kept as short as possible or avoided in favor of OAC plus single antiplatelet therapy (SAPT) based on the individual's ischemic and bleeding risk profile (Class IIa, Level B-NR). (7) For patients with unruptured brain arteriovenous malformations there is no indication to change antiplatelet or anticoagulant management instituted for management of another disease (Class IIb, Level C-LD). (8) Patients with symptomatic intracranial atherosclerotic disease (ICAD) should continue DAPT following neurointerventional treatment for secondary stroke prevention (Class IIa, Level B-NR). (9) Following neurointerventional treatment for ICAD, DAPT should be continued for at least 3 months. In the absence of new stroke or transient ischemic attack symptoms, reversion to SAPT can be considered based on an individual patient's risk of hemorrhage versus ischemia (Class IIb, Level C-LD). (10) Patients undergoing carotid artery stenting (CAS) should receive DAPT before and for at least 3 months following their procedure (Class IIa, Level B-R). (11) In patients undergoing CAS during emergent large vessel occlusion ischemic stroke treatment, it may be reasonable to administer a loading dose of intravenous or oral glycoprotein IIb/IIIa or P2Y12 inhibitor followed by maintenance intravenous infusion or oral dosing to prevent stent thrombosis whether or not the patient has received thrombolytic therapy (Class IIb, C-LD). (12) For patients with cerebral venous sinus thrombosis, anticoagulation with heparin is front-line therapy; endovascular therapy may be considered particularly in cases of clinical deterioration despite medical therapy (Class IIa, Level B-R).

CONCLUSIONS

Although the quality of evidence is lower than for coronary interventions due to a lower number of patients and procedures, neurointerventional antiplatelet and antithrombotic management shares several themes. Prospective and randomized studies are needed to strengthen the data supporting these recommendations.

Suspected Rivaroxaban-Induced Anaphylaxis Secondary to Ingestion of Rivaroxaban and Nimesulide Without Cross-Reactivity to Dabigatran - A Case Report

Here, we describe a case of anaphylaxis secondary to rivaroxaban in a 61-year-old woman 24 hours after orthopedic surgery. 10-15 minutes after ingestion of rivaroxaban and nimesulide, the patient's palms started itching, her face and lips swelled, her face flushed, she developed shortness of breath and subsequently lost consciousness. Serum tryptase levels at the time of the anaphylactic reaction were elevated, with subsequent measurement one month later returning a value within the normal range. Dabigatran and meloxicam were identified as suitable alternative drugs by oral provocation at an allergy clinic. Even though rivaroxaban rarely causes serious allergic reactions, when prescribing it, it is important to analyze patients' medical history for possible previously experienced drug-induced allergic reactions and to be aware of the risks of possible undesired drug interactions.

Practice patterns surrounding referral to a specialty venous thromboembolism (VTE) clinic: a retrospective review

This study audited prescribing practices for patients with acute venous thromboembolism (VTE) prior to and after being seen in an outpatient VTE clinic. This retrospective chart review conducted between June 2018 through May 2019 included patients with confirmed acute VTE, seen for an initial appointment. Exclusion criteria were patients with additional indications for anticoagulation, lack of information to determine primary outcome and active cancer. To assess practices, the time taken to be seen in clinic, anticoagulant therapies (prior to/following clinic) used and concordance of anticoagulant use with product monographs were assessed. Of the 325 (40.6%) patients included, the median age was 57.7 years, most were referred with pulmonary embolism (PE) (54.5%) and the majority of referrals came through the emergency department (45.2%). The median time to be seen in clinic was 13 days, with no differences in time between type of VTE or proximity of clot. Prior to being seen in VTE clinic, most were prescribed direct oral anticoagulants (DOACs) (81.9%), with a small portion receiving low molecular weight heparin (LMWH) (12.9%) and warfarin (5.2%). Most received anticoagulants concordant with product monographs (87.7%), with more discordance with warfarin (52.9%) and LMWH (14.3%) compared to DOACs (9.4%) (P < 0.001). At the initial VTE clinic visit, 70 (21.5%) patients had therapy changes, with most being from LMWH/warfarin to a DOAC (47.1%). Our data reflects high uptake of DOACs for acute VTE treatment with most prescribed in accordance with product monographs.

Use of Direct Oral Anticoagulants Versus Traditional Therapies for Acute Venous Thromboembolism After Direct Discharge From the Emergency Department or After Hospitalization: An Audit of 16 Canadian Hospitals

PURPOSE

This study compares and describes the use of direct oral anticoagulants (DOACs) versus traditional therapies (parenteral anticoagulant with or without warfarin) for acute venous thromboembolism (VTE) between individuals discharged directly from the emergency department (ED) versus those hospitalized. This study also reports patterns based on discharge from an academic, community, or rural-based site.

METHODS

This retrospective medical records study included patients discharged with acute VTE (2015-2016) from 16 institutions across 4 provinces. Patients with atypical clots, other indications for anticoagulants, or an anticipated lifespan <3 months or those who were pregnant or breastfeeding were excluded.

FINDINGS

Overall, 590 individuals (30.0%) discharged from the ED and 809 (53.8%) discharged after hospitalization were studied. Hospitalized patients were significantly older, had more comorbidities (cancer, pulmonary disease, and heart failure), and were more likely to have pulmonary embolism than deep vein thrombosis. DOAC use was significantly higher in the ED cohort versus the hospitalized cohort (51.4% vs 44.3%; P < 0.004) and more common for those having lower risk of pulmonary embolisms (simplified Pulmonary Embolism Severity Index score of 0 compared with ≥1) in the ED (58.0% and 26.5%; P < 0.0001) and hospitalized cohorts (57.1% and 35.7%; P < 0.0001). Use of DOACs was lowest in academic settings (46.2%) and highest in rural sites (56.7%). Follow-up patterns were different, with specialists and VTE clinics being most common in academic sites and family physicians being most common in rural practices.

IMPLICATIONS

DOACs were used in less than half of all patients, with more use in EDs and rural sites. Follow-up patterns (VTE clinic or specialist vs family physician) varied and likely contributed to therapy selection. Over time, use of DOACs is likely to increase, and patient factors (eg, those younger with fewer comorbidities) and health care contact (eg, place of discharge or availability of an ambulatory VTE clinic) will likely continue to influence practice patterns.

Reversal of direct oral anticoagulants: Guidance from the Anticoagulation Forum

Two specific reversal agents for direct oral anticoagulants (DOACs) have been approved in the United States: idarucizumab for dabigatran reversal and andexanet alfa for apixaban and rivaroxaban reversal. Non-specific prohemostatic agents such as prothrombin complex concentrate (PCC) and activated PCC have also been used for DOAC reversal. The goal of this document is to provide comprehensive guidance from the Anticoagulation Forum, a North American organization of anticoagulation providers, regarding use of DOAC reversal agents. We discuss indications for reversal, provide guidance on how the individual reversal agents should be administered, and offer suggestions for stewardship at the health system level.

Hospital length of stay in patients initiated on direct oral anticoagulants versus warfarin for venous thromboembolism: a real-world single-center study

This study was conducted to describe the real-world hospital length of stay in patients treated with all of the U.S. Food and Drug Administration approved direct oral anticoagulants (DOACs) versus warfarin for new-onset venous thromboembolism (VTE) at a large, tertiary, academic medical center. A retrospective cohort analysis of all adult patients diagnosed with acute onset VTE was conducted. Of the 441 patients included, 261 (57%) patients received DOACs versus 180 (41%) patients received warfarin. In the DOAC group, a total of 92 (35%) patients received rivaroxaban, followed by 83 (32%) patients received apixaban, 50 (19%) patients received dabigatran, and 36 (14%) patients received edoxaban. Patients initiated on DOACs had a statistically significant shorter hospital length of stay compared to patients initiated on warfarin (median 3 days, [IQR 0-5] vs. 8 days [IQR 5-11], P < 0.05). Despite the shorter hospital length of stay in patients receiving DOACs, the overall reported differences between the DOACs group and the warfarin group in terms of recurrent VTE, major bleeding, intracranial bleeding, and gastrointestinal bleeding at 3 and 6 months were deemed to be statistically insignificant.

Temporal trends in initiation of VKA, rivaroxaban, apixaban and dabigatran for the treatment of venous thromboembolism - A Danish nationwide cohort study

Danish nationwide registries were used to investigate temporal trends in initiation of rivaroxaban or apixaban or dabigatran versus vitamin K antagonists (VKA) in patients with venous thromboembolism (VTE). Patients treated with one of the NOACs (rivaroxaban, dabigatran, apixaban) or VKA were identified between February 2012 and September 2016. A total of 19,578 patients were included of which 10,844 (55.4%) were treated with VKA and 8,734 (44.6%) were treated with NOACs (rivaroxaban 7,572, apixaban 1,066, and dabigatran 96). Temporal trends showed a decrease in the initiation of VKA (p-value for decreasing trend, p < 0001) and an increase in the initiation of rivaroxaban and apixaban (p-value for increasing trend, p < 0001). By September 2016, 12%, 70%, 16%, and 2% of patients with VTE were initiated on VKA, rivaroxaban, apixaban, and dabigatran. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with one of the NOACs. In conclusion the initiation of rivaroxaban and apixaban is increasing significantly over time in patients with VTE. Patients with previous VTE, chronic kidney disease, liver disease, cancer, and thrombophilia were more likely to be initiated on VKA compared with rivaroxaban or apixaban.

NOACs for treatment of venous thromboembolism in clinical practice

Randomised controlled trials have provided important information on the efficacy and safety of the non-vitamin K antagonist oral anticoagulants (NOACs) for treatment of venous thromboembolism (VTE), leading to registration and increasing use in clinical practice. Many questions remain to be answered, and observational studies are often more suitable for answering "real-world" questions than randomised controlled trials. Patient satisfaction, quality of life, and adherence and persistence in clinical practice with the drug regimen can only be assessed with an open-label design. Evaluation of risk for long-term sequelae of the disease requires much longer follow-up than is possible in registration trials. Treatment patterns and utilisation of health care resources can be assessed from observations in the clinical practice setting. We will review published as well as currently active observational studies with NOACs in VTE, with or without a comparator anticoagulant. These studies are based on cohorts of different sizes, registries, or administrative health care databases. We will also discuss some limitations in analysis and interpretation of observational studies.