Two-Week Wearable Heart Monitor After Unexplained Fainting Doubles Arrhythmia Detection and Halves One-Year Death Rate
核心洞察
A 14-day wearable ECG monitor fitted within 72 hours of A&E attendance more than doubled detection of clinically significant arrhythmias (22% vs. 9%) in 2,233 patients with unexplained syncope (搜索).
One-year all-cause mortality was nearly halved in the monitoring group (1.5% vs. 2.9%), alongside earlier diagnosis (median 22 vs. 55 days) and higher rates of pacemaker implantation and anti-arrhythmic therapy.
The primary endpoint of recurrent syncope (搜索) showed no significant difference (1.37 vs. 1.58 episodes; IRR 0.89; 95% CI 0.68–1.18; p=0.43), but researchers argue the survival benefit supports routine ED use.
Fitting patients who attend the emergency department (ED) with a wearable heart monitor for 14 days more than doubled the detection of life-threatening heart rhythm problems and was associated with a near-halving of the one-year death rate, according to results from the ASPIRED trial presented in a Hot Line session at ESC Congress 2026 and published simultaneously in the New England Journal of Medicine.
The Edinburgh-led trial, funded by the British Heart Foundation, enrolled 2,233 adults (mean age 58.3 years; 48% female) across 45 UK hospitals, making it the largest randomised trial to date assessing immediate ambulatory ECG monitoring in patients with unexplained syncope (搜索). Syncope, also called fainting or blackout, accounts for around 650,000 ED visits in the UK every year. While most cases are benign, some are caused by potentially life-threatening cardiac arrhythmias.
Earlier Detection of Hidden Arrhythmias
Using the two-week monitor, which is about the size of a car key fob and worn in the middle of the chest, more than doubled the detection rate of heart rhythm problems. After one year, clinically significant cardiac arrhythmias were identified in 22% of the monitor group compared with 9% of those receiving standard care.
The monitoring strategy also led to earlier diagnosis. Heart rhythm problems were identified in a median of 22 days in those with chest-worn monitors, compared with 55 days with standard care. This included life-threatening arrhythmias such as complete heart block, ventricular tachycardia, and a pause in the heartbeat of over six seconds.
Professor Matthew Reed, Professor of Emergency Medicine at the University of Edinburgh and Principal Investigator of the ASPIRED trial, said: "We were able to begin patient monitoring within 72 hours of people arriving at A&E, much faster than the current standard."
He added: "Continuous data on a patient's heart rhythm for two weeks is invaluable to cardiologists when they are trying to diagnose an arrhythmia (搜索). As the results show, more patients with hidden heart rhythm problems were identified, and their treatment could be sped up."
A Survival Benefit Despite No Change in Recurrent Fainting
The death rate after one year in the two-week monitoring group, at 1.5%, was almost half that of the standard care group, at 2.9% — a 50% reduction in all-cause mortality. However, the trial's primary endpoint showed no significant difference in the mean number of self-reported syncope (搜索) episodes at one year (1.37 vs. 1.58; incidence rate ratio 0.89; 95% confidence interval 0.68 to 1.18; p=0.43).
Improved detection nonetheless translated into more patients receiving treatment. In the monitoring group, 10.8% were given anti-arrhythmic medication and 6.8% had a pacemaker implanted, versus 7.3% and 4.6% respectively in the standard care group.
"Although immediate ECG monitoring did not reduce recurrent fainting, it enabled earlier identification of serious cardiac rhythm disorders, allowing patients to receive treatment much sooner, reducing uncertainty and anxiety, and potentially preventing avoidable deaths," summarized Professor Reed. "These findings suggest that early monitoring should be considered as part of routine ED care for patients with unexplained syncope (搜索), while further research explores the observed survival benefit."
Why Arrhythmias Are Often Missed
Arrhythmias in patients with unexplained fainting are difficult to diagnose. People who have fainted have usually recovered by the time they reach the ED, meaning their heart rhythm has likely returned to normal, and tests performed in the ED will not show any abnormalities.
Currently, patients with unexplained fainting are referred for tests such as a Holter monitor, a small wearable device that records the heart's rhythm. However, a Holter monitor is usually worn for only 48 hours, so it can only identify an arrhythmia (搜索) within this narrow time window. Patients must also attend an outpatient cardiology clinic first, meaning monitoring is done at any point from six weeks to two years after their ED attendance.
In the ASPIRED trial, half of the study volunteers who attended one of 45 UK EDs with unexplained fainting were fitted with the new monitor, while the other half received current standard monitoring. Participants were instructed to press a button on the heart monitor if they experienced another syncopal event, and patients in both groups recorded any syncopal episodes in a paper diary. Data from the monitors were sent to clinicians after the two-week period, who then determined whether recordings showed signs of an arrhythmia (搜索) and whether treatment was needed. If the monitor had picked up a serious arrhythmia, the patient's clinician was alerted within 24 working hours.
Implications for Clinical Practice
The researchers hope that now the new strategy has been shown to help doctors treat more dangerous heart problems and reduce death rates, it will become standard practice in the NHS. Professor Bryan Williams, Chief Scientific and Medical Officer at the British Heart Foundation, said: "This large trial is a good example of how BHF investment in research can drive life changing innovations in healthcare."
He added: "The study shows that monitoring the heart with simple new technology after a patient has had a sudden collapse can identify potentially life-threatening disturbances in heart rhythm that can be treated to reduce risk of death. The results of this trial should certainly help inform future clinical practice when treating patients with sudden unexplained collapse in the future."
Patients also reported very high acceptability of the monitoring device. Stephen, a 68-year-old trial participant from West Lothian who joined after fainting twice within a week, described the device as "very user friendly," noting that it "goes in the middle of your chest and it's small enough that it doesn't get in the way at all." Data from his device revealed that his atrial fibrillation (搜索) was not being controlled by his medication, with his heart beating at 227 beats per minute at certain points, prompting clinicians to raise his dosage of bisoprolol. "I haven't fainted since, it looks like the treatment has been working," he said.