Fainting with no clear cause: a 14-day ECG patch from the ER found more than twice as many arrhythmias but did not cut repeat faints, NEJM trial shows

Many people who come to the emergency department after fainting (syncope) leave without a clear explanation. A heart-rhythm problem may be the cause but can be missed. The ASPIRED trial, published in the New England Journal of Medicine (29 October 2026 print issue; results first presented at the ESC Congress in August), tested whether attaching a 14-day ambulatory ECG patch at the first visit helps.

The study

• Design: open-label randomised controlled trial at 45 UK hospitals, funded by the British Heart Foundation and NHS Research Scotland.
• Patients: 2,234 adults with syncope unexplained after ED evaluation (mean age 58.3); 1,123 got the patch, 1,111 standard care.
• Primary outcome: mean number of patient-reported fainting episodes at 1 year.

Results

• Primary outcome — no significant difference: 1.37 vs 1.58 episodes (incidence rate ratio 0.89; P=0.42). About 28% in each group fainted again.
• Clinically relevant arrhythmias found in 22.0% vs 9.0% (odds ratio 2.95), and found sooner (median 22 vs 54.5 days).
• More patients started anti-arrhythmic treatment (10.8% vs 7.3%) or got a pacemaker (6.8% vs 4.6%).
• All-cause death at 1 year was 1.5% vs 2.9% (odds ratio 0.50), a secondary finding.
• Adverse events: 49 vs 8, with one serious event in each group.

Limitations

The trial was open-label, and the primary outcome relied on self-reported episodes; 264 randomised patients gave no follow-up and were excluded from the primary analysis. The lower death rate is a secondary outcome with few events, so it should be seen as hypothesis-generating rather than proof. The trial was conducted in the UK NHS. Patients with fainting should discuss testing options with their doctor.