Warfarin control in patients transitioning to warfarin after non-vitamin K oral anticoagulant (NOAC) therapy

Oral anticoagulant switching in patients with atrial fibrillation: a scoping review

INTRODUCTION

Oral anticoagulants (OACs) prevent stroke in patients with atrial fibrillation (AF). Several factors may cause OAC switching.

OBJECTIVES

To examine the phenomenon of OAC switching in patients with AF, including all available evidence; frequency and patterns of switch, clinical outcomes, adherence, patient-reported outcomes, reasons for switch, factors associated with switch and evidence gaps.

DESIGN

Scoping review.

DATA SOURCES

MEDLINE, Embase and Web of Science, up to January 2022.

RESULTS

Of the 116 included studies, 2/3 examined vitamin K antagonist (VKA) to direct-acting OAC (DOAC) switching. Overall, OAC switching was common and the definition of an OAC switch varied across. Switching from VKA to dabigatran was the most prevalent switch type, but VKA to apixaban has increased in recent years. Patients on DOAC switched more to warfarin than to other DOACs. OAC doses involved in the switches were hardly reported and patients were often censored after the first switch. Switching back to a previously taken OAC (frequently warfarin) occurred in 5%-21% of switchers.The risk of ischaemic stroke and gastrointestinal bleeding in VKA to DOAC switchers compared with non-switchers was conflicting, while there was no difference in the risk of other types of bleeding. The risk of ischaemic stroke in switchers from DOAC versus non-switchers was conflicting. Studies evaluating adherence found no significant changes in adherence after switching from VKA to DOAC, however, an increase in satisfaction with therapy were reported. Reasons for OAC switch, and factors associated with OAC switch were mostly risk factors for stroke and bleeding. Clinical outcomes, adherence and patient-reported outcomes were sparse for switches from DOACs.

CONCLUSIONS

OAC switching is common in patients with AF and patients often switch back to an OAC they have previously been on. There are aspects of OAC switching that have received little study, especially in switches from DOACs.

[Venous stenting in acute period of total and subtotal deep vein thrombosis]

OBJECTIVE

To study the efficacy and safety of venous stenting and long-term anticoagulation with inhibitors of blood clotting factor XA in the treatment of total and subtotal deep vein thrombosis.

MATERIAL AND METHODS

We analyzed 60 patients with total and subtotal deep vein thrombosis divided into 2 comparable groups by 30 people. Patients of the first group underwent regional catheter thrombolysis and percutaneous mechanical thrombectomy. The same endovascular treatment supplemented by venous stenting was performed in the second group. In the first group, rivaroxaban was prescribed before, during and for 6 months after surgery; apixaban was used in the second group. Complications of endovascular and anticoagulant therapy were recorded. After 12 months, control ultrasound and clinical examination of patients was performed to analyze recanalization of deep veins and severity of venous outflow disorders. Recanalization of veins was evaluated as follows: less than 50% - minimal, 50-99% - partial, 100% - complete.

RESULTS

In the first group, complete and partial recanalization of veins was found in 63.3 and 36.7% of patients, respectively. In the second group, these values were 93.3 and 6.7%, respectively. In the first group, venous outflow disorders were absent in 56.7%, mild violations presented in 36.6%, moderate violations - in 6.7% of patients. In the second group, venous outflow was normal in 93.3% of patients, and mild disorders presented in 6.7% of patients. Hemorrhagic complications developed in 8 (13.3%) patients, equally in both groups.

[One-year results of conservative and endovascular treatment of deep venous thrombosis followed by severe acute venous insufficiency]

OBJECTIVE

To compare the results of conservative and endovascular treatment of deep vein thrombosis followed by acute severe venous insufficiency.

MATERIAL AND METHODS

Two statistically valid groups of patients with deep vein thrombosis and acute severe venous insufficiency were compared. Warfarin was administered in the first group, endovascular methods - in the second group (n=30). At the first step, we performed catheter-guided thrombolysis, then transcutaneous mechanical thrombectomy and venous stent deployment. Anticoagulation was achieved with Apixaban. Hemorrhagic complications were monitored during the treatment. One-year results were assessed considering lumen patency restoration and severity of venous congestion with Villalty score.

RESULTS

In the first group, each third patient had hemorrhagic complications that required cessation of anticoagulant therapy in 1.3% of patients. In the second group, hemorrhagic events occurred in 10% of patients and were managed by lowering Apixaban dosage. Complete restoration of lumen patency was detected in 23.3% in the first group and 93.3% in the second group. Partial restoration developed in 63.3% and 6.7%, occlusion in 13.3% and 0%, respectively. Only 23.3% of patients in the first group had no clinical evidence of venous congestion. Mild congestion was found in 20%, severe - in 56.7% of cases. In the second group, 6.7% of patients had minimal venous congestion.

The SAMe-TT2R2 Score Predicts Warfarin Control in an Australian Population with Atrial Fibrillation

BACKGROUND

Warfarin requires regular monitoring with the time in therapeutic range (TTR), a common indicator of control and TTR > 70% is indicative of efficient anticoagulation. The SAMe-TT2R2 (sex, age, medical history, treatment, tobacco use, race) model has been utilised as a predictor of warfarin control, with a score ≥ 2 indicative of poor control. However, it has been suggested that race may be over-represented in this model. To date, no Australian studies have applied this model, possibly because race is not routinely recorded. Therefore, the aim of this study was to apply the SAMe-TT2R2 model in an Australian population on warfarin managed by both a warfarin care program (WCP) and general practitioner (GP).

METHODS

Retrospective data was collected for patients receiving warfarin via a WCP in Queensland and whilst being managed by a GP. Patient data was used to calculate the SAMe-TT2R2 score and the TTR for each patient. Mean TTR was used for analysis and comparison with the categorised SAMe-TT2R2 score.

RESULTS

Of the 3911 patients managed by a WCP, there was a significantly lower mean TTR for patients with a SAMe-TT2R2 score ≥ 2 compared to 0-1 (78.6 ± 10.7% vs. 80.9 ± 9.5%, p < 0.0001). Of these patients, 200 were analysed whilst managed by a GP and the categorised SAMe-TT2R2 score did not result in a statistically different mean TTR (69.3 ± 16.3% with 0-1 vs. 63.6 ± 15.0% with ≥2, p = 0.089), but a score ≥2 differentiated patients with a TTR less than 65%.

CONCLUSIONS

The SAMe-TT2R2 model differentiated Australian patients with reduced warfarin control, despite the exclusion of race. In Australia, the SAMe-TT2R2 score could assist clinicians in identifying Australian patients who may obtain reduced warfarin control and benefit from additional interventions such as a dedicated WCP.

Treatment Expectations, Convenience, and Satisfaction with Anticoagulant Treatment: Perceptions of Patients in South-East Queensland, Australia

Background: Warfarin has long been the only oral anticoagulant (OAC) available, but options now include non-vitamin K antagonists. Prescribing an OAC may be influenced by patient factors and preferences influenced by dosing, monitoring, and adverse effects, which may ultimately impact patient satisfaction and convenience. The aim of this study was to explore the perception of OAC treatment by Australian patients in terms of treatment expectations, convenience, and satisfaction. Methods: The Perception of Anticoagulant Treatment Questionnaire was distributed to patients dispensed OAC medication from three pharmacies in South-East Queensland. Responses to questions using a five-point Likert scale were collated and mean results utilised to assess expectations, convenience, and satisfaction, including an analysis across demographic groups. Results: A total of 56 (26.8%) surveys were returned, with the majority of respondent’s male (58.2%). Highest mean scores for treatment expectation were for an OAC that was easy to take (4.85 ± 0.79) and that could be taken care of by the respondents themselves (4.11 ± 1.14). The mean overall score for convenience was 68.90 ± 11.44% and for satisfaction 69.43 ± 16.58%. Significantly higher mean convenience scores were found in females and patients with atrial fibrillation. Conclusions: Patients’ highest expectations were for an OAC that would be easy to take, and overall satisfaction and convenience was around 69%. Factors including demographics can influence perceptions of therapy, and addressing individual preferences for OAC therapy may increase ratings of satisfaction and convenience.