Off-label Use for Direct Oral Anticoagulants: Valvular Atrial Fibrillation, Heart Failure, Left Ventricular Thrombus, Superficial Vein Thrombosis, Pulmonary Hypertension-a Systematic Review

Platelet hyperresponsiveness and increased platelet-neutrophil aggregates in dogs with myxomatous mitral valve disease and pulmonary hypertension

BACKGROUND

Pulmonary hypertension (PH) in dogs with myxomatous mitral valve disease (MMVD) is caused by increased pulmonary venous pressure. Thrombosis, vascular remodeling, and vasoconstriction mediated by platelets could exacerbate PH.

HYPOTHESIS

Dogs with PH will exhibit a hypercoagulable state, characterized by increased platelet activation, platelet-leukocyte, and platelet-neutrophil aggregate formation.

ANIMALS

Eleven dogs (≥3.5 kg) diagnosed with MMVD and PH and 10 dogs with MMVD lacking PH.

METHODS

Prospective cohort ex vivo study. All dogs underwent echocardiographic examination, CBC, 3-view thoracic radiographs, and heartworm antigen testing. Severity of PH and MMVD were assessed by echocardiography. Viscoelastic monitoring of coagulation was assessed using thromboelastography (TEG). Platelet activation and platelet-leukocyte/platelet-neutrophil interactions were assessed using flow cytometry. Plasma serotonin concentrations were measured by ELISA.

RESULTS

Unstimulated platelets from dogs with MMVD and PH expressed more surface P-selectin than MMVD controls (P = .03). Platelets from dogs with MMVD and PH had persistent activation in response to agonists. The number of platelet-leukocyte aggregates was higher in dogs with MMVD and PH compared with MMVD controls (P = .01). Ex vivo stimulation of whole blood resulted in higher numbers of platelet-neutrophil aggregates in dogs with MMVD and PH (P = .01). Assessment of hypercoagulability based on TEG or plasma serotonin concentrations did not differ between groups.

CONCLUSION AND CLINICAL IMPORTANCE

Platelet hyperresponsiveness and increased platelet-neutrophil interaction occur in dogs with MMVD and PH, suggesting that platelets play a role of in the pathogenesis of PH. Clinical benefits of antiplatelet drugs in dogs with MMVD and PH require further investigation.

Direct oral anticoagulants compared with warfarin in patients with left ventricular thrombus: a cohort study from China

Background

Current guidelines recommend vitamin K antagonist (VKA) for left ventricular (LV) thrombus. This study aimed to compare the effectiveness and safety of direct oral anticoagulant (DOAC) and warfarin in Chinese patients with LV thrombus.

Methods

Patients with LV thrombus admitted to Beijing Anzhen Hospital of Capital Medical University between January 2018 and January 2022, were enrolled in this cohort study. The primary endpoint was defined as thrombus resolution within 90 days. The secondary endpoints included thrombus resolution within 180 days, major bleeding events, and minor bleeding events. All patients were followed up for at least 90 days after diagnosis of LV thrombus. Patients were divided into the VKA and DOAC groups according to the anticoagulants. Differences in clinical endpoint events between the two groups were compared.

Results

This study included 129 and 111 patients in the VKA and DOAC groups, respectively. After adjusting for gender and smoking status, no significant difference was observed in thrombus resolution within 90 days between the VKA and DOAC groups. Additionally, there was no difference between the two groups in the secondary endpoints of thrombus resolution within 180 days, major bleeding, and minor bleeding. In subgroup analysis, rivaroxaban and dabigatran did not show significant differences in primary and secondary endpoints.

Conclusions

This study showed no significant difference in thrombus resolution between DOAC and warfarin. DOAC might be an alternative to warfarin for the treatment of LV thrombus. However, further large prospective studies are required to explore the efficacy and safety of DOAC in patients with LV thrombus.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Off-Label Dosing of Direct Oral Anticoagulants Among Inpatients With Atrial Fibrillation in the United States

BACKGROUND

Among patients hospitalized for atrial fibrillation, the frequency of off-label direct oral anticoagulant (DOAC) dosing, associated factors, hospital-level variation, and temporal trends in contemporary practice are unknown.

METHODS

Using the Get With The Guidelines-Atrial Fibrillation registry, patients admitted from January 1, 2014, to March 31, 2020, and discharged on DOACs were stratified according to receipt of underdosing, overdosing, or recommended dosing. Factors associated with off-label dosing (defined as underdosing or overdosing) were identified using logistic regression. Median odds ratio (OR) and time-series analyses were used to assess hospital-level variation and temporal trends, respectively.

RESULTS

Of 22 470 patients (70.1±12.1 years, 48.1% female, 82.5% White) prescribed a DOAC at discharge from hospitalization for atrial fibrillation (66% apixaban, 29% rivaroxaban, and 5% dabigatran), underdosing occurred among 2006 (8.9%), overdosing among 511 (2.3%), and recommended dosing among 19 953 (88.8%). The overall rate of off-label dosing was 11.2%. Patient-related factors associated with off-label dose included age (underdosing: OR, 1.06 per 1-year increase [95% CI, 1.06-1.07]; overdosing: OR, 1.07 per 1-year increase [95% CI, 1.06-1.09]), dialysis dependence (underdosing: OR, 5.50 [95% CI, 3.76-8.05]; overdosing: OR, 5.47 [95% CI, 2.74-10.88]), female sex (overdosing: OR, 0.79 [95% CI, 0.63-0.99]), and weight (overdosing: OR, 0.96 per 1-kg increase [95% CI, 0.95-1.00]). Across hospitals, the adjusted median OR for off-label DOAC dose was 1.45 (95% CI, 1.34-1.65; underdosing: OR, 1.52 [95% CI, 1.39-1.76]; overdosing: OR, 1.32 [95% CI, 1.20-1.84]), indicating significant hospital-level variation. Over the study period, recommended dosing significantly increased over time (81.9%-90.9%; P<0.0001 for trend) with a corresponding decline in underdosing (14.4%-6.6%; P<0.0001 for trend) and overdosing (3.8%-2.5%; P=0.001 for trend).

CONCLUSIONS

Over 1 in 10 patients hospitalized for atrial fibrillation are discharged on an off-label DOAC dose with significant variation across hospitals. While the proportion of patients receiving recommended dosing has significantly improved over time, opportunities to improve DOAC dosing persist.

Assessment of non-vitamin K antagonist oral anticoagulants for the management of left ventricular thrombus

Although several studies have assessed the effect of non-vitamin K antagonist oral anticoagulants (NOACs) relative to that of vitamin K antagonists (VKAs) in patients with left ventricular thrombus, the results remain controversial. Herein, a meta-analysis was performed to compare the effectiveness and safety of NOACs versus VKAs for the treatment of left ventricular thrombus. We systematically searched the Cochrane Library, PubMed and Embase databases until November 2020 for studies that compared the effects of NOACs versus VKAs in patients with left ventricular thrombus. The treatment effects were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) and pooled by a random-effects model. Seven retrospective studies involving 865 patients with left ventricular thrombus (266 NOAC and 599 VKA users) were included. The pooled analysis suggested no difference in the rate of thrombus resolution between the NOAC and VKA groups (OR = 0.83, 95% CI 0.61-1.13). There were also no differences in the rates of stroke or systemic embolism (OR = 0.62, 95% CI 0.20-1.97), bleeding events (OR = 0.73, 95% CI 0.37-1.45), or all-cause death (OR = 0.92, 95% CI 0.50-1.69) between patients treated with NOACs and those treated with VKAs. In addition, the rates of thrombus resolution, stroke or systemic embolism, bleeding events, and all-cause death between NOAC- and warfarin-treated patients were also similar. Our current evidence suggested that NOAC and VKA users had similar rates of thrombus resolution and clinical outcomes among patients with left ventricular thrombus. Further large-scale prospective studies should confirm our results.