This research is Trending!
View all ESC 2026 trials
Immediate Ambulatory Electrocardiographic Monitoring in Syncope
Key result
Immediate 14-day wearable ECG monitoring fails to reduce syncope episodes at one year versus standard practice.
- IRR 0.89
- 95% CI 0.68 to 1.18
- P=0.42
- n=2,234
Why the trial?
Unexplained syncope often goes undiagnosed for months under standard monitoring, delaying treatment of underlying arrhythmias. ASPIRED asked whether immediate enhanced ambulatory ECG monitoring shortens the time to diagnosis and improves management.
Does 14-day ambulatory ECG monitoring reduce the mean number of patient-reported episodes of syncope at 1 year in adults with unexplained syncope after emergency department evaluation?
Population
2,234 adults with syncope unexplained after ED evaluation (mean age 58.3)
Comparison
Immediate 14-day ambulatory ECG monitoring vs standard care
Design
Open-label randomized controlled trial (1:1) at 45 UK hospitals
Follow-up
1 year
Authors
Discussion
No takes yet. Share an insight, caveat, or question.
Key expert perspectives
Captured external expert commentary on this trial, strongest first. Original sources are linked where available.
The ASPIRED trial randomised 2,233 adults with unexplained syncope across 45 UK hospitals to immediate 14-day ambulatory ECG monitoring versus standard care. While the primary endpoint of self-reported syncope episodes at one year was not significantly different, monitoring more than doubled arrhythmia detection, shortened time to diagnosis, and increased pacemaker implantation and anti-arrhythmic therapy rates. The trial was simultaneously published in NEJM.
“@DrDerekConnolly @DLBHATTMD @ESC_President @PZoungas @vass_vassiliou @mmartinezheart @ShelleyZieroth @robmentz @JennaSkowronski @noshreza @gabrielsteg @co_kobo @elmir1omerovic @Aspirinbk @RizosKonsta @escardio @HighSTEACS @SimoneBiscaglia @KardiologieHH @Marta33717088 @Bweber04 @RonBlankstein @purviparwani @MariamElmegaard @ankeetbhatt @kpnorcal @ratika_parkash @DalhousieU @HeartDocSharon @CMichaelGibson @BaimInstitute @mortschou @shaoliang_chen @panniyammakal @dranulala @heartofthemater @mmamas1973 @WGCPMChair @EAPCIPresident @EACVIPresident @BarbaraStahli @j_hausleiter @oyvlie @RigsHeart @HeartcentreC @netta_doc @LiverpoolCCS @RoWachter @CERG_NTNU @karolinskainst #HOTLINE 10 #ESCCongress Syncope-Stopper & #ASPIRED push us toward smarter syncope workups (since there is so much syncope, I need to hear these talks!) HIS Alternative II asks if His pacing should be our new HF default vs BiV pacing”
MKMD Kemal Karaagac
“Among patients with syncope that remained unexplained after evaluation in the emergency department, the use of 14-day ambulatory ECG monitoring did NOT result in significantly fewer patient-reported syncope episodes at 1 year than standard care.”
“ASPIRED #ESCCongress 2,233 pts with unexplained syncope presenting to ER (48% women ) → immediate 14-day ECG monitor vs usual care No ↓ recurrent syncope at 1 yr, BUT: Arrhythmia detection: 22% vs 9% Mortality: 1.5% vs 2.9% Early monitoring finds actionable”
Implication
Immediate 14-day ECG monitoring does not reduce syncope recurrence at 1 year; challenges routine adoption despite higher arrhythmia detection in unexplained syncope.
NEJM · ESC 2026 · RCT. Immediate 14-day ECG monitoring after syncope doesn't reduce recurrence at 1 year. ASPIRED: Immediate Ambulatory Electrocardiographic Monitoring in Syncope Unexplained syncope often goes undiagnosed for months under standard monitoring, delaying treatment of underlying arrhythmias. Does 14-day ambulatory ECG monitoring reduce the mean number of patient-reported episodes of syncope at 1 year in adults with unexplained syncope after emergency department evaluation? 2234 participants, Open-label randomized controlled trial…. Arrhythmia detection: 14-day ECG 22% vs Standard 9%. Read with care. Adverse events were 49 vs 8, with 1 serious adverse event in each arm. The trial was open-label with a self-reported primary outcome whose large standard deviations (±5.10 and ±8.56)… 264 patients (11.8%) with no follow-up were excluded from the primary analysis. Where experts stand: Dr. Matthew J. Reed (Professor of Emergency Medicine · The Usher…): “Although immediate ECG monitoring did not reduce recurrent fainting, it enabled earlier identification of serious cardiac rhythm disorders, allowing…” Martha Gulati (Cardiologist · @drmarthagulati): “@DrDerekConnolly @DLBHATTMD @ESC_President @PZoungas @vass_vassiliou @mmartinezheart @ShelleyZieroth @robmentz @JennaSkowronski @noshreza…” From their public comments on the paper Still open: Should the mortality difference change practice despite a neutral primary endpoint? Read the evidence. See where experts stand. synapsesocial.com/papers/6a8fbb6617152b56e6b6483a
Key Points
- To assess whether immediate 14-day ambulatory electrocardiographic (ECG) monitoring reduces recurrent syncope episodes at 1 year in patients presenting to the emergency department with unexplained syncope.
- Open-label, randomized controlled trial conducted across 45 hospitals in the United Kingdom (ISRCTN10278811).
- Enrolled 2234 adults with syncope unexplained after emergency department evaluation, randomly assigned 1:1 to receive 14-day ambulatory ECG monitoring (N=1123) or standard care (N=1111), with 1-year follow-up.
- In the primary analysis (N=1970), the mean (±SD) number of patient-reported syncope episodes at 1 year was 1.37±5.10 in the intervention group versus 1.58±8.56 in the standard-care group (incidence rate ratio, 0.89; 95% CI, 0.68 to 1.18; P=0.42).
- Adverse events occurred in 49 patients in the 14-day monitoring group versus 8 patients in the standard-care group, with 1 serious adverse event reported in each arm.
Evidence details
What drove the result?
| Outcome | 14-day ECG | Standard |
|---|---|---|
| Patient-reported syncope episodes at 1 year (mean) | 1.37 | 1.58 |
| Primary · IRR 0.89 (95% CI 0.68–1.18; p=0.42) — no significant reduction | ||
| Arrhythmia detection | 22% | 9% |
| From the trial record; not reported in the publication abstract | ||
| All-cause mortality | 1.5% | 2.9% |
| From the trial record, not the abstract · hypothesis-generating only | ||
Limitations & tradeoffs
Safety
Adverse events were 49 vs 8, with 1 serious adverse event in each arm.
Design limitations
The trial was open-label with a self-reported primary outcome whose large standard deviations (±5.10 and ±8.56) indicate highly skewed episode counts.
Statistical certainty
264 patients (11.8%) with no follow-up were excluded from the primary analysis.
Subgroup caution
Arrhythmia-detection and mortality figures come from the trial record rather than the publication abstract.
Structured PICO
Does 14-day ambulatory ECG monitoring reduce the mean number of patient-reported episodes of syncope at 1 year in adults with unexplained syncope after emergency department evaluation?
P
Population
2,234 adults with unexplained syncope after emergency department evaluation, randomized to 14-day ambulatory ECG monitoring or standard care, followed for 1 year.
I
Intervention
14-day ambulatory electrocardiographic (ECG) monitoring
C
Comparator
Standard care provided for patients with unexplained syncope at each participating site
O
Outcome
Mean number of patient-reported episodes of syncope at 1 yearpatient reported
Main Result
Relative Risk: 0.89 (95% CI 0.68–1.18)
Absolute Event Rate: 1.37% vs 1.58%
p-value: p=0.42
In patients with unexplained syncope after emergency department evaluation, 14-day ambulatory ECG monitoring did not significantly reduce patient-reported syncope episodes at 1 year compared to standard care.
Coverage & sources
Journal, society, and media accounts. Useful signal, not independent expert judgment.
Cite This Study
Reed et al. (2026) conducted an RCT in Unexplained syncope (n=2,234). 14-day ambulatory electrocardiographic (ECG) monitoring vs. Standard care was evaluated on Mean number of patient-reported episodes of syncope at 1 year (IRR 0.89, 95% CI 0.68 to 1.18, p=0.42). 14-day ambulatory ECG monitoring did not significantly reduce the mean number of patient-reported syncope episodes at 1 year compared to standard care (IRR 0.89; 95% CI 0.68-1.18; P=0.42).