Non-vitamin K Antagonist Oral Anticoagulants and Drug-Food Interactions: Implications for Clinical Practice and Potential Role of Probiotics and Prebiotics

Non-vitamin K antagonist oral anticoagulants (NOACs) are a therapeutic option to prevent stroke in patients with atrial fibrillation (AF). In fact, NOACs have become the recommended choice by international clinical practice guidelines over vitamin K antagonists (VKA), because of their efficacy and safety profile, especially in newly initiated patients. The more predictable pharmacokinetic and pharmacodynamic profile of this family of drugs allows preventing anticoagulation drug monitoring. Furthermore, NOACs have significantly fewer drug and food interactions in comparison with VKAs. Despite this, there are no studies that compare the effects on the quality of anticoagulation of NOACs with the intake of potential interactions drugs of P-glycoprotein and cytochrome P450 (CYP). This review brings an overview of NOACs pharmacokinetics profile and their potential drug-food interactions. We also briefly discuss the potential role of prebiotics and probiotics in patients under therapy with NOACs.

Acute hemorrhage and death in calves following chlorophacinone exposure

Three calves were submitted to the Iowa State University Veterinary Diagnostic Laboratory for diagnostic evaluation following an abrupt increase in morbidity and mortality in a calf herd associated with epistaxis and widespread hemorrhage. Each of the submitted calves had moderate-to-severe hemorrhage within various tissues and body cavities, including the thymus, subcutaneous region of the neck, mediastinum, lungs, pericardial sac, heart, spleen, perirenal fat, urinary bladder, and skeletal muscle, including the diaphragm. An anticoagulant rodenticide screen was performed on the livers of each calf. Significant concentrations of chlorophacinone were detected at 4.2, 3.6, and 2.9 ppm in liver. Multiple piles and an open pail of white powdery material were present within the facility in which the calves were housed and were identified as the sources of chlorophacinone. Acute hemorrhage and death occurred in fourteen 1.5-mo-old, crossbred calves following ingestion of the vitamin K antagonist chlorophacinone.

Outcomes of left atrial appendage occlusion vs. non-vitamin K antagonist oral anticoagulants in atrial fibrillation

Background The effects of left atrial appendage (LAA) occlusion compared to non-vitamin K antagonist oral anticoagulant (NOAC) therapy in patients with atrial fibrillation (AF) remain unknown. Aims We aimed to evaluate the outcomes in patients with AF who received LAA occlusion vs. NOAC therapy. Methods We utilised data from TriNetX which is a global federated health research network currently containing data for 88.5 million patients. ICD-10 codes were employed to identify AF patients treated with either LAA occlusion or NOAC between 1st December 2010 and 17th January 2019. Clinical outcomes of interest were analysed up to 2 years. Results 108,697 patients were included. Patients who underwent LAA occlusion were younger, more likely to be white Caucasian and male, had a greater incidence of comorbidities, and were less likely to be prescribed other cardiovascular medications. Using propensity score matching, the risk of all-cause mortality was significantly lower among patients who received LAA occlusion compared to NOAC therapy [1.51% vs. 5.60%, RR 0.27 (95% CI 0.14–0.54)], but there were no statistical differences in the composite thrombotic or thromboembolic events [8.17% vs. 7.72%, RR 1.06 (95% CI 0.73–1.53)], ischaemic stroke or TIA [4.69% vs. 5.45%, RR 0.86 (95% CI 0.54–1.38)], venous thromboembolism [1.66% vs. 1.51%, RR 1.10 (95% CI 0.47–2.57)] and intracranial haemorrhage [1.51% vs. 1.51%, RR 1.00 (95% CI 0.42–2.39)]. Conclusion Overall, LAA occlusion might be a suitable alternative to NOAC therapy for stroke prevention in patients with AF. Graphical abstract

Use of Direct Oral Anticoagulant and Outcomes in Patients With Atrial Fibrillation after Transcatheter Aortic Valve Replacement: Insights From the STS/ACC TVT Registry

Background Clinical evidence on the safety and effectiveness of using direct oral anticoagulants (DOACs) in patients with atrial fibrillation after transcatheter aortic valve replacement (TAVR) remains limited. The aim of this study was to investigate the trends and outcomes of using DOACs in patients with TAVR and atrial fibrillation. Methods and Results Data from the STS/ACC TVT (Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy) Registry was used to identify patients who underwent successful TAVR with preexisting or incident atrial fibrillation who were discharged on oral anticoagulation between January 2013 and May 2018. Patients with a mechanical valve, valve‐in‐valve procedure, or prior stroke within a year were excluded. The adjusted primary outcome was 1‐year stroke events. The adjusted secondary outcomes included bleeding, intracranial hemorrhage, and death. A total of 21 131 patients were included in the study (13 004 TAVR patients were discharged on a vitamin K antagonist and 8127 were discharged on DOACs.) The use of DOACs increased 5.5‐fold from 2013 to 2018. The 1‐year incidence of stroke was comparable between DOAC‐treated patients and vitamin K antagonist‐treated patients (2.51% versus 2.37%; hazard ratio [HR], 1.00; 95% CI, 0.81–1.23) whereas DOAC‐treated patients had lower 1‐year incidence of any bleeding (11.9% versus 15.0%; HR, 0.81; 95% CI, 0.75–0.89), intracranial hemorrhage (0.33% versus 0.59%; HR, 0.54; 95% CI, 0.33–0.87), and death (15.8% versus 18.2%; HR, 0.92; 95% CI, 0.85–1.00). Conclusions In patients with TAVR and atrial fibrillation, DOAC use, when compared with vitamin K antagonists, was associated with comparable stroke risk and significantly lower risks of bleeding, intracranial hemorrhage, and death at 1 year.

Evaluation of the Modified SAMe-TT2R2 Score to Predict Good Anticoagulation Control with Warfarin Among non-valvular Atrial Fibrillation Patients

Background: The SAMe-TT2 R2 Score was developed to identify vitamin K antagonists control outliers before non-valvular atrial fibrillation (AF) patients start treatment. SAMe-TT2 R2 Score was derived and validated using a primarily white Caucasian population to predict TTR. Given that non-Caucasian race already confers 2 points in this score, the SAMe-TT2 R2 score requires validation and/or re-calibration despite race of population. Method: We conducted a cohort retrospective study that included all non-valvular atrial fibrillation patients who were on warfarin therapy from January to December 2019. Then we calculated the modified SAMe-TT2 R2 and SAMe-TT2 R2 for all study populations and we correlated the result with patients' TTR. The TTR was calculated through the Rosendaal's method. Results: We had 662 patient using warfarin therapy, among those 662, 60.9% were under cardiology and using it for cardiac indication, and only 18.1% diagnosed to have non-valvular AF. Modified SAMe-TT2 R2 score has good relation to original SAMe-TT2 R2 score as showed 75.71% (95% CI. 63.99 to 85.17%), 100% (95% CI. 92.89 to 100%) and 15% (95% CI. 3.21 to 77.95%); accuracy, sensitivity and specificity in relation to SAMe-TT2 R2 respectively. In addition to that in this small cohort we found that there is universal relationship between SAMe-TT2 R2 score, Modified SAMe-TT2 R2 score and TTR; TTR >=65% associate with low score (<2) of both SAMe-TT2 R2 , Modified SAMe-TT2 R2 score. Conclusion: The use of Modified SAMe-TT2 R2 score allows clinicians to make an informed decision on whether to start vitamin K antagonist or other non-vitamin K antagonist oral anticoagulant despite the race of the patients.

Safety and differences between direct oral anticoagulants and vitamin K antagonists in the risk of post-traumatic intrathoracic bleeding after rib fractures in elderly patients

Closed chest traumas are frequent consequences of falls in the elderly. The presence of concomitant oral anticoagulant therapy can increase the risk of post-traumatic bleeding even in cases of trauma with non-severe dynamics. There is limited information about the differences between vitamin K antagonists and direct oral anticoagulants in the risk of post-traumatic bleeding. To assess differences in the risk of developing intra-thoracic hemorrhages after chest trauma with at least one rib fracture caused by an accidental fall in patients over 75 years of age taking oral anticoagulant therapy. This study involved data from four emergency departments over two years. All patients on oral anticoagulant therapy and over 75 years of age who reported a closed thoracic trauma with at least one rib fracture were retrospectively evaluated. Patients were divided into two study groups according their anticoagulant therapy. Of the 342 patients included in the study, 38.9% (133/342) were treated with direct oral anticoagulants and 61.1% (209/342) were treated with vitamin K antagonist. A total of 7% (24/342) of patients presented intrathoracic bleeding, while 5% (17/342) required surgery or died as a result for the trauma. Posttraumatic intrathoracic bleeding occurred in 4.5% (6/133) of patients receiving direct oral anticoagulants and 8.6% (18/209) of patients receiving vitamin K antagonist. Logistic regression analysis, revealed no difference in the risk of intrathoracic haemorrhages between the two studied groups. Direct oral anticoagulants therapy presents a risk of post-traumatic intrathoracic haemorrhage comparable to that of vitamin K antagonist therapy.

Case Report: Leaflet Thrombosis After Transcatheter Aortic Valve Replacement With Worsening Heart Failure—A Successful Resolution Using Non-vitamin K Antagonist Oral Anti-coagulant

Background: Transcatheter aortic valve replacement (TAVR) is indicated for treating symptomatic severe aortic valve stenosis (AS) with intermediate-to-high surgical risks. Few reports are available on managing leaflet thrombosis after TAVR with worsening heart failure.Case Summary: A 77-year-old man with severe AS and coronary artery disease (CAD) received a successful TAVR with Edwards Sapien 3 valve. A year later, the patient developed a worsening heart failure with pulmonary edema, new-onset atrial fibrillation (Af), an increase in mean trans-aortic valve pressure gradient to 48 mmHg, worsening mitral regurgitation (MR), and pulmonary hypertension (PH). The response of the patient to intravenous diuretics and inotropic treatments was poor. Multi-slice CT (MDCT) revealed hypo-attenuated thrombus and thickened transcatheter heart valve leaflets. A non-vitamin K antagonist oral anti-coagulant (NOAC) was added to treat the new-onset Af and leaflet thrombosis on top of the con-current single antiplatelet for CAD. A series of follow-up echocardiograms showed a progressive decrease in trans-aortic valve pressure gradient to 17 mmHg and reductions in MR and PH. Three months after the NOAC treatment, MDCT revealed the resolution of hypo-attenuated thrombus and thickened leaflets. Symptoms of heart failure were also improved gradually.Discussion: Worsening heart failure or an increase in trans-aortic valve pressure gradient after TAVR warranted further MDCT studies. Leaflet thrombosis can be resolved after using NOAC as in our present case.