TS
Tomas SharmaSep 8
Hi
Anticoagulation for Atrial Fibrillation with Intermediate Stroke Risk
Why the trial?
Guidelines firmly recommend anticoagulation at high stroke risk and against it at low risk, but atrial fibrillation with intermediate risk (CHA2DS2-VA 1) sits in an evidence gap. Whether the stroke protection of a DOAC outweighs its bleeding cost in these patients had never been settled in a dedicated randomised trial.
Does DOAC therapy reduce the composite of stroke, systemic embolism, major bleeding, or cardiovascular death in patients with atrial fibrillation at intermediate risk for stroke compared to no anticoagulation?
Population
1803 patients with AF at intermediate stroke risk (mean age 60.4, 23.7% women)
Comparison
DOAC therapy vs no anticoagulation
Design
Randomized controlled trial, 1:1 (blinding not reported; South Korea)
Follow-up
24 months
Key result
In patients with intermediate-risk atrial fibrillation, DOAC therapy reduced stroke, systemic embolism, major bleeding, or CV death compared to no anticoagulation (HR 0.31; 95% CI 0.10-0.94; P=0.03).
Authors
Discussion
2 takesMember takes
Where experts stand
Experts broadly read SINGLE-AF as the first randomized evidence supporting DOAC therapy in intermediate-risk AF, with many calling it practice-changing, though some flag very low event rates and a single-country cohort as reasons for caution.
Cardiologists and electrophysiologists are welcoming the result as long-awaited randomized backing for a guideline recommendation that previously rested on observational data alone. The dominant reaction is that this trial strengthens the case for anticoagulating AF patients with a single non-sex stroke risk factor. The live question is whether the low absolute event rates and the exclusively South Korean population allow confident generalization to broader, more diverse settings.
Agreement
Multiple clinicians agree that SINGLE-AF provides the first randomized evidence supporting DOAC therapy in AF patients at intermediate stroke risk, filling a gap that current guidelines addressed only with observational data.
4 clinicians say this directly
What they’re arguing about
supportiveneutralcautiouscritical
Counts are expert takes we classified by axis. Tap a row to see the takes behind its count.
Still unclear
Whether these findings generalize beyond a South Korean population, given the single-country cohort and very low overall event rates. It also remains open whether guidelines will upgrade the class IIa recommendation to a stronger endorsement on the basis of one trial, and whether longer follow-up or larger studies are needed to confirm the bleeding safety signal.
Key expert perspectives
SINGLE-AF is practice-changing and reminds us undertreatment has consequences
Calls SINGLE-AF the first randomized evidence supporting DOAC therapy in intermediate-low stroke risk AF and labels it practice-changing. Adds that the broader message is that while clinicians increasingly discuss when not to anticoagulate, this trial highlights the real cost of undertreatment.
This trial may shift the anticoagulation threshold in AF
Frames SINGLE-AF as the first randomized evidence addressing the longstanding question of whether to anticoagulate intermediate-risk AF patients. Highlights the 69% relative reduction in adverse outcomes with DOACs as a signal that the treatment threshold may need to move.
RCT evidence finally backs the class IIa guideline call
Summarizes the key numbers and frames the result as randomized evidence that finally supports the existing class IIa guideline recommendation for anticoagulation in intermediate-risk AF.
Distilled from their postX post
Overview
Supports DOAC use in intermediate-risk AF; extends randomized evidence beyond high-risk populations.
Key Points
- To determine whether direct oral anticoagulant therapy reduces cardiovascular events compared with no anticoagulation in patients with atrial fibrillation at intermediate risk for stroke.
- Randomized trial (SINGLE-AF, NCT04437654) enrolling 1803 patients with atrial fibrillation and intermediate stroke risk, assigned 1:1 to direct oral anticoagulant (DOAC) therapy (N=902) or no anticoagulation (N=901).
- Follow-up lasted 24 months to assess the primary composite end point of stroke, systemic embolism, major bleeding, or cardiovascular death.
- The primary composite end point occurred in 4 patients (cumulative incidence, 0.5%) in the DOAC group versus 13 patients (cumulative incidence, 1.5%) in the no-anticoagulation group (difference, -1.0 percentage points; 95% CI, -2.0 to -0.1; P = 0.03; HR, 0.31; 95% CI, 0.10 to 0.94).
- Stroke occurred in 3 patients (0.3%) in the DOAC arm versus 10 patients (1.1%) in the control arm, with similar rates of systemic embolism and major bleeding between groups and no cardiovascular deaths in either group.
- Serious adverse events occurred in 80 patients (8.9%) in the DOAC group and 84 patients (9.3%) in the no-anticoagulant group.
Evidence details
What drove the result?
| Outcome | DOAC | No OAC |
|---|---|---|
| Stroke, systemic embolism, major bleeding, or CV death | 4 (0.5%) | 13 (1.5%) |
| HR 0.31 (95% CI 0.10-0.94); difference -1.0 pp (-2.0 to -0.1); P=0.03 | ||
| Stroke | 3 (0.3%) | 10 (1.1%) |
| Composite component - drove the result | ||
| Death from cardiovascular causes | 0 | 0 |
| No cardiovascular deaths in either group | ||
Limitations & tradeoffs
Safety
Serious adverse events 80/902 (8.9%) vs 84/901 (9.3%).
Statistical certainty
only 17 primary end-point events occurred, and the wide CI (0.10-0.94) is compatible with anything from a large to a minimal benefit.
Representation
patients were relatively young (mean 60.4 years) and enrolled in South Korea.
Structured PICO
Does DOAC therapy reduce the composite of stroke, systemic embolism, major bleeding, or cardiovascular death in patients with atrial fibrillation at intermediate risk for stroke compared to no anticoagulation?
P
Population
1,803 patients (mean age 60.4 years, 23.7% women) with atrial fibrillation at intermediate risk for stroke, followed for 24 months.
I
Intervention
Direct oral anticoagulant (DOAC) therapy
C
Comparator
No anticoagulation
O
Outcome
Composite of stroke, systemic embolism, major bleeding, or death from cardiovascular causes at 24 monthscomposite
Main Result
Hazard Ratio: 0.31 (95% CI 0.1–0.94)
Absolute Event Rate: 0.5% vs 1.5%
Absolute Risk Reduction: 1%
p-value: p=0.03
In patients with atrial fibrillation at intermediate stroke risk, DOAC therapy significantly reduced the composite risk of stroke, systemic embolism, major bleeding, or cardiovascular death at 24 months compared to no anticoagulation.
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Cite This Study
Kim et al. (2026) conducted an RCT in Atrial fibrillation with intermediate stroke risk (n=1,803). Direct oral anticoagulant (DOAC) therapy vs. No anticoagulation was evaluated on Composite of stroke, systemic embolism, major bleeding, or death from cardiovascular causes at 24 months (HR 0.31, 95% CI 0.10 to 0.94, p=0.03). In patients with intermediate-risk atrial fibrillation, DOAC therapy reduced stroke, systemic embolism, major bleeding, or CV death compared to no anticoagulation (HR 0.31; 95% CI 0.10-0.94; P=0.03).