ECG screening in the home can improve the long-term detection of atrial fibrillation in older patients with an elevated risk of stroke, new research suggests.
In the study, participants who wore a ECG monitoring patch for two weeks were more likely to have an AF diagnosis two-and-a-half years later than those who were not remotely screened.
Patients who underwent remote screening were also treated with anticoagulants for an average of two weeks longer over the follow-up period.
Dr Rohan Wijesurendra. Source: Nuffield Health
“However, AF diagnosis unrelated to the patch occurred more commonly than anticipated and over half of the patch-detected AF burden was low burden (below 10%),” commented lead study author Dr Rohan Wijesurendra, a consultant cardiologist and electrophysiologist at the Oxford University Hospitals NHS Foundation Trust.
“This suggests that AF screening in this setting may have limited impact on stroke events,” he added.
The AMALFI study, published in JAMA [link here], recruited 5,040 older adults (mean age 78 years, 47% female) with a moderate-to-high risk of stroke (CHA2DS2VASc score of at least 3 for men, or at least 4 for women) and no history of AF or atrial flutter, who were randomised to receive remote screening (n=2,520) or usual care (n=2,520).
Participants who underwent remote screening were sent a self-applied, non-invasive single-lead ECG patch (Zio XT, iRhythm) which they wore for 14 days, allowing continuous ambulatory monitoring, and then returned by post.
In total, 2,126 participants (84%) wore and returned the ECG patch, with AF detected in 89 patients (4%).
In the majority of these cases (55%) the AF burden was less than 10%, although a third of patients (33%) had an AF burden of 100%.
Two-and-a-half years after randomisation, primary care data showed that 6.8% in the remote screening group had a record of AF – a significantly higher proportion than the 5.4% who received standard care (p=0.03).
At the same time point, similar proportions of patients in the remote monitoring and usual care groups had been prescribed oral anticoagulants (14% vs 13%), but mean exposure to oral anticoagulation was longer in the remote monitoring group (1.63 months vs 1.14 months, p<0.001).
However, the rate of stroke was similar in both the remote screening and usual care arms (2.7% vs 2.5%), while the risk of cardiovascular death and any-cause death were also comparable.
“We found that the rate of AF diagnosis in the control group in AMALFI and the proportion of individuals in the intervention group whose clinical AF diagnosis was unrelated to the patch were both substantially higher than predicted ahead of the trial,” wrote the study authors.
“Consequently, the difference in the proportion of patients with an AF diagnosis in each group at 2.5 years was much closer than expected,” they said.
Taken together, findings of the trial show that mail-based AF screening in older patients at moderate to high risk of stroke “led to a modest long-term increase in AF diagnosis at 2.5 years”, but that its impact on stroke events was limited, the authors concluded.