Edoxaban may be an effective alternative to warfarin—the current standard of care—for patients undergoing bioprosthetic valve surgery, new research has shown.
Chisato Izumi (National Cerebral and Cardiovascular Center, Suita, Japan) presented findings of the ENBALV trial, in which researchers compared edoxaban to warfarin in 410 patients undergoing aortic or mitral valve replacement surgery at 24 centres in Japan, at the American Heart Association (AHA) 2024 Scientific Session (16–18 November, Chicago, USA).
Embolic events such as stroke are high after bioprosthetic valve surgery, Izumi noted in her presentation, especially among patients without anticoagulation therapy, and is typically caused by thrombus formation around the valve, perioperative atrial fibrillation (AF) and cardiac dysfunction shortly after the procedure.
Warfarin, a vitamin K antagonist, is presently the only recommended anticoagulant for this group of patients, but comes with several disadvantages, including a narrow therapeutic range which requires frequent blood tests for dose adjustment, as well as interactions with various other drugs and foods.
“These are burdens on patients and medical staff,” commented Izumi, noting that, by contrast, direct oral anticoagulants (DOACs) can be used with a constant dose, without the need for frequent blood tests for monitoring anticoagulation activity. “If DOACs were available for this group of patients, it could simplify the care process and reduce the burden on patients and medical staff,” she said.
The ENBALV trial evaluated the effectiveness and safety of edoxaban, which was approved by the US Food and Drug Administration (FDA) in 2015 for patients with non-valvular AF, compared to warfarin within three months after bioprosthetic valve surgery. Researchers randomised the participants into two equal groups to receive either edoxaban or warfarin for 12 weeks after their surgery.
Reporting on an analysis among 389 of the 410 enrolled patients, the investigators found edoxaban was equally or more effective than warfarin at preventing stroke and systemic embolism, with 0.5% of patients receiving edoxaban having a stroke or systemic embolism, compared to 1.5% of patients receiving warfarin.
Major bleeding was higher among patients receiving edoxaban, occurring in 4.1% of the edoxaban group and in 1% of the warfarin group, though no fatal bleeding or intracranial haemorrhage was observed in patients treated with edoxaban, whereas one fatal cerebral haemorrhage occurred in the warfarin group. Intracardiac thrombus did not occur in any of the patients in the edoxaban group, but did occur in 1% of patients in the warfarin group. Additionally, patients who received edoxaban did experience higher instances of gastrointestinal bleeding compared to patients who received warfarin (2.1% vs. 0%, respectively).
“Our findings show that edoxaban could help prevent blood clots and stroke as effectively as warfarin, indicating that it is a viable post-surgery treatment alternative to consider for patients who have received a bioprosthetic heart valve replacement,” Izumi said. “Edoxaban could make life easier for patients recovering from heart valve surgery. Since this medication does not require regular blood tests to monitor anticoagulation activity and can be taken in a fixed dose, without fears of interaction with food or other medications, it reduces the burden on patients and improves their quality of life, especially in those crucial first few months after surgery.”
Researchers have said that future research is needed to understand which patients have the highest risk of bleeding with the use of edoxaban and how to mitigate this risk while still offering effective treatment options in post-surgery treatment and recovery.
“Edoxaban can be considered for this indication,” commented Manesh Patel (Duke University School of Medicine, Durham, USA) who summarised the implications of the findings following Izumi’s presentation. “I would say this area of our practice has to importantly improve the stratification of patients importantly undergoing valvular surgery, specifically those that are undergoing bioprosthetic valvular surgery without known atrial fibrillation to see who is at risk for stroke and systemic embolism in that short term period.”
