Wearable ECG patch improves AF diagnosis in mSToPS
A wearable electrocardiogram (ECG) chest patch markedly improves the rate of atrial fibrillation (AF) diagnosis vs routine care in the digital, nationwide mSToPS* trial.
“The quality of data collected through the patch is as good as what we see clinically,” said lead investigator Dr Steven Steinhubl from the Scripps Translational Science Institute in La Jolla, California, US. “At 1 year, patients who wore the chest monitor had nearly thrice the likelihood of being diagnosed with AF. A significant proportion of them was started on anticoagulant therapy to lower their stroke risk.”
The primary endpoint of the incidence of AF was 6.3 percent (unadjusted odds ratio [OR], 2.8; p<0.0001) in patients monitored using the ECG patch vs 2.3 percent (adjusted OR, 3.0; p<0.0001) in those monitored with routine care at 1 year. Active monitoring led to a significantly higher rate of initiating anticoagulant therapy (5.4 percent vs 3.4 percent in controls). There was also a small but significant increase in antiarrhythmic therapy (0.8 percent vs 0.3 percent) and pacemaker or implantable cardioverter-defibrillator placement (0.7 percent vs 0 percent) in the active monitoring group. [ACC.18,18-LB-18063]
Steinhubl and colleagues sought to determine if participant-generated data available through the ECG patch can better identify AF relative to routine care and facilitate timely anticoagulation.
mSToPs included 1,738 Aetna members aged ≥75 years with prior cerebrovascular accident or heart failure, diabetes and hypertension, or obstructive sleep apnoea, who were enrolled through a web-based platform to undergo active monitoring at home with the iRhythm Zio patch that records an ECG continuously. Patients had no known AF but at moderate risk. They were taught how to apply the patch and made to wear it for an average of 12 days. Each case was matched with two controls of similar age-, sex-, and CHA2DS2-VASc (n=3,476). Data on AF treatment, physician and emergency department visits, blood clot, and stroke events were collected.
Patients on ECG patch had significantly more primary care visits vs controls (78.7 percent vs 75 percent) and cardiology outpatient visits (31.6 percent vs 23.6 percent). There was no difference in stroke rate between groups (1.9 percent vs 2.1 percent). Emergency department visits or hospitalizations were also comparable.
“We found that remote AF monitoring is a feasible, scalable, and clinically valuable way to screen for AF in an at-risk nationwide population,” said Steinhubl. “Monitoring is associated with greater initiation of guideline-recommended therapies, with increased healthcare utilization at 1 year.”
However, he acknowledged that one of the limitations of the study was the low percentage of patients approached who consented. “Only 5.4 percent of patients who received an invitation to participate in mSToPS actually enrolled in the trial.
Thirty-eight percent of those who initially consented to participate never got to wear the patch due to a lack of built-in digital prompting,” Steinhubl said.
AF is the most commonly sustained arrhythmia. For those over the age of 55, there is about a 37 percent lifetime risk of developing AF, he said. “AF is associated with a fivefold increased risk for stroke and a twofold increased risk for mortality. Fortunately, once recognized, therapeutic anticoagulation can decrease the risk for stroke by about 65 percent and mortality by 30 percent.”
Further follow-up through 3 years is planned to better understand the clinical impact of ECG patch monitoring in patients at moderate risk of developing AF, he concluded.