Anticoagulation Monotherapy vs Antiplatelet Monotherapy After Transcatheter Aortic Valve Implant
View Full PaperWhy the trial?
The optimal antithrombotic regimen after TAVI is unsettled: aspirin is standard, yet leaflet thrombosis is frequent and its prevention unproven. ACASA-TAVI asked whether NOAC monotherapy protects the valve better without excess bleeding.
Does NOAC monotherapy reduce valve leaflet thrombosis and maintain safety compared to ASA monotherapy in patients aged 65-80 years undergoing TAVI for severe aortic valve stenosis?
Population
360 patients aged 65–80 undergoing TAVI for severe AS (mean 74.5; 37% female)
Comparison
Factor Xa NOAC monotherapy vs aspirin (ASA) monotherapy for 12 months
Design
Randomized (1:1), open-label, blinded-endpoint trial at 3 Norwegian centres
Follow-up
12 months
Key result
NOAC monotherapy reduced TAVI valve leaflet thrombosis at 12 months compared to ASA monotherapy (16.2% vs 28.6% (27/167 vs 48/168); risk ratio 0.55, 95% CI 0.37-0.82; P=0.004) and was noninferior for safety (7.5% vs 10.6%; risk difference -3.3%, 95% CI -9.5% to 2.8%; P for noninferiority <0.001).
Authors
Interventional · Oslo University Hospital
Looking forward to discussing ACASA-TAVI with this community.
ACASA-TAVI co-author
Replying to
Looking forward to discussing ACASA-TAVI with this community.
Wouldn’t it be better to diagnose subclinical valve thrombosis first with CT followed bij randomisation of only positive patients to continuing ASA vs DOAC (POPULAR ATLANTIS)
Captured external expert commentary on this trial, strongest first. Original sources linked on every quote.
“@ShariqShamimMD @djc795 We will report 5 and 10 year data on durability and outcomes, but ultimately we need a dedicated clinical outcomes trial. ACASA-TAVI underscores the need for such a monotherapy vs. monotherapy trial.”
“@ShariqShamimMD @djc795 I would not recommend changing practice based on ACASA-TAVI, but I would consider using SAPT rather than DAPT. ACASA-TAVI does challenge the perception of the risk of NOAC therapy in the younger patients, but stronger evidence on effect on hard outcomes should come first.”
NOAC monotherapy reduces TAVI leaflet thrombosis with noninferior safety; extends antithrombotic options beyond aspirin in moderate-risk patients.
| Outcome | NOAC | ASA |
|---|---|---|
| HALT (valve leaflet thrombosis) on 4D CT at 12 months | ||
| Co-primary efficacy · in-world sources disagree (abstract 16.2% vs 28.6%; structured record 17.2% vs 32.6%); values withheld pending review |
Safety
VARC-3 bleeding, thromboembolic events, or death (co-primary safety) occurred in 13 (7.5%) vs 19 (10.6%); RD −3.3% (95% CI −9.5% to 2.8%); noninferior (p<0.001).
Design limitations
In-world sources disagree on the primary HALT rates, so the efficacy result needs manual reconciliation.
Subgroup caution
HALT is a subclinical imaging endpoint; its link to clinical events is not established by this trial.
Representation
Findings apply to patients aged 65–80 without another indication for anticoagulation.
Does NOAC monotherapy reduce valve leaflet thrombosis and maintain safety compared to ASA monotherapy in patients aged 65-80 years undergoing TAVI for severe aortic valve stenosis?
In patients aged 65-80 undergoing TAVI, NOAC monotherapy for 12 months significantly reduced subclinical valve leaflet thrombosis and was noninferior for clinical safety events compared to standard aspirin monotherapy.
Relative Risk: 0.55 (95% CI 0.37–0.82)
Absolute Event Rate: 16.2% vs 28.6%
p-value: p=.004
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Dodgson et al. (2026) conducted an RCT in Severe aortic valve stenosis (n=360). NOAC monotherapy vs. Acetylsalicylic acid (ASA) monotherapy was evaluated on TAVI valve leaflet thrombosis defined as the presence of hypoattenuated leaflet thickening (HALT) on blinded core laboratory 4-dimensional cardiac computed tomographic (CT) scan at 12 months (RR 0.55, 95% CI 0.37 to 0.82, p=.004). NOAC monotherapy reduced TAVI valve leaflet thrombosis at 12 months compared to ASA monotherapy (16.2% vs 28.6% (27/167 vs 48/168); risk ratio 0.55, 95% CI 0.37-0.82; P=0.004) and was noninferior for safety (7.5% vs 10.6%; risk difference -3.3%, 95% CI -9.5% to 2.8%; P for noninferiority <0.001).
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