Anticoagulant Monotherapy Reduces Thrombosis, Improves Bleeding After TAVI

Anticoagulation therapy after transcatheter aortic valve implantation (TAVI) substantially reduced subclinical leaflet thrombosis and was noninferior for bleeding, thromboembolic events, and death compared with acetylsalicylic acid (ASA) monotherapy in the recent ACASA-TAVI trial.¹

These data, presented at the European Society of Cardiology (ESC) Congress 2026 in Munich, Germany, by Oyvind Lie, MD, PhD, MSc, a senior consultant in interventional cardiology at Oslo University Hospital in Norway, represent a step forward in challenging guideline recommendations for treatment and management post-TAVI. Currently, US guidelines strongly discourage anticoagulation in patients without an independent indication, based on results from 2 trials evaluating combinations of anticoagulants and antiplatelet therapies. The present trial contrasts this recommendation with evidence of the potential efficacy of anticoagulant monotherapy in this population.¹

“We have seen during observational studies and related trials that the prevalence of thrombotic processes on the leaflets of the TAVI valves is substantially lower in patients who have anticoagulation therapy, meaning patients with atrial fibrillation, venous thromboembolism, or other indications,” Lie told HCPLive in an exclusive interview. “This raised the question of whether or not there is merit to the anticoagulation domain of antithrombotic therapy, which led us into constructing this trial.”

ACASA-TAVI was a multicenter, randomized controlled trial that enrolled patients aged >65 and <80 years who had undergone successful TAVI. Patients with a strict indication or contraindication for anticoagulation or antiplatelet therapy, overt cognitive failure, or concomitant use of inducers or inhibitors of CYP3A4 or P-glycoprotein were excluded.²

Participants were then randomly assigned in a 1:1 ratio to 12 months of treatment with either a factor Xa inhibitor non-vitamin K antagonist oral anticoagulant (NOAC) for the duration of the study and changed over to ASA indefinitely following the study (intervention) or to ASA monotherapy indefinitely (control). Patients assigned to receive NOAC began standard dosing of any commercially available anti-factor Xa NOAC within 72 hours of TAAVI, with standard dosing of 5 mg apixaban twice daily, 60 mg edoxaban once daily, or rivaroxaban 20 mg once daily. The ASA cohort received 75 mg ASA without dose adjustments.¹

The study’s co-primary endpoints were hypoattenuated leaflet thickening (HALT) and a safety composite of bleeding events, thromboembolic events, and all-cause death at 12 months. Secondary endpoints included a clinical efficacy composite of freedom from all-cause mortality, stroke, hospitalization for procedure- or valve-related causes, and Kansas City Cardiomyopathy Questionnaire overall summary score of ≤45 or a decline from baseline of ≥10 points, among other criteria.¹

A total of 1983 patients were scanned, of whom 360 were enrolled – 180 patients were assigned to each group. In the NOAC group, 51% were given apixaban, 41% received edoxaban, and 8% received rivaroxaban. 11 patients in the ASA group received clopidogrel instead of ASA. A total of 47 patients had treatment deviations. 36 patients crossed over, 5 aborted therapy, and 6 had temporary treatment interruptions. All patients completing the trial with no deviations reported good adherence.¹

The co-primary efficacy endpoint occurred in 27 of 167 patients receiving NOAC (16.2%) and in 48 of 168 patients receiving ASA (28.6%) (risk ratio, 0.55; 95% CI, 0.37 to 0.82; P = .004). The number of patients with grade 1 HALT was similar between groups, but more severe HALT was more common in the ASA cohort. The primary safety endpoint occurred in 13 patients from the NOAC group (7.5%) and in 19 patients from the ASA group (10.6%) (absolute risk difference, -3.3%; 95% CI, -9.5% to 2.8%).¹

Ultimately, Lie and colleagues concluded that the present study serves as a demonstration for the efficacy of NOAC treatment following TAVI, contradicting widely accepted guideline recommendations. However, the team also notes a handful of limitations associated with the study, including its open-label design and the inability to extrapolate the results to older patients undergoing TAVI due to its focus on younger patients.¹

“I think the paradigm is challenged; how that will materialize into new practice guidelines, I am not the one to decide,” Lie said. “But this is absolutely not enough evidence to turn the guidelines around. For that, we need larger studies, longer-term follow-up, and convincing clinical outcomes.”

Editors’ Note: Lie reports disclosures with Edwards Lifesciences, Medtronic, and Abbott.

References

1. Dodgson CS, Herstad J, Kløve SF, et al. Anticoagulation monotherapy vs Antiplatelet Monotherapy after transcatheter aortic valve implant. JAMA. Published online August 30, 2026. doi:10.1001/jama.2026.17036

2. Oslo University Hospital. AntiCoagulation Versus AcetylSalicylic Acid After Transcatheter Aortic Valve Implantation (ACASA-TAVI). ClinicalTrials.gov Identifier: NCT05035277. Updated June 9, 2026. Accessed September 10, 2026. https://clinicaltrials.gov/study/NCT05035277