Pieter M. Vandervoort
MUNICH — A smartphone app designed to screen for atrial fibrillation using noninvasive plethysmography was shown to be safe and effective in patients, detecting mostly asymptomatic cases in a manner that can easily reach a large population, according to data from the DIGITAL-AF study presented at the European Society of Cardiology Congress.
“One out of four of you in the audience will develop atrial fibrillation at some point in your lifetime, resulting in 14 to 17 million people with atrial fibrillation in the [European Union] by 2030,” Pieter M. Vandervoort, MD, PhD, from the department of cardiology at Ziekenhuis Oost-Limburg in Genk, Belgium, said during a presentation. “We know that people with AF have a 1.5- to twofold increase in mortality; however, we know that treatment with anticoagulation may prevent morbidity and mortality.”
ESC guidelines recommend opportunistic screening by pulse palpation or ECG in adults aged 65 years and older, as well as systematic ECG screening in adults aged at least 75 years or those at increased risk for stroke, Vandervoort said. Additionally, ECG and 72-hour monitoring are recommended for all patients presenting with transient ischemic attack or stroke.
“Currently, the ECG and the 24-hour Holter monitor are the gold standard for diagnosing atrial fibrillation,” Vandervoort said. “However, they are cumbersome and are only available in the doctor’s office or hospital. So, more innovative technologies are being developed to diagnose and detect atrial fibrillation.”
Vandervoort and colleagues analyzed data from 12,328 adults (mean age, 49 years; 42% women), recruited via a local newspaper article to use FibriCheck (Qompium), a medically certified app in Europe (CE class IIa) to detect heart rhythm disorders via a smartphone. The app uses pulse plethysmogram (PPG), a measure of variations in the capillary volume resulting from ventricular contractions in the arterial BP wave. These changes in volume, Vandervoort said, can be picked up via smartphone camera, which can decompose the signal in its RGB components for further analysis.
Participants received instructions on how to download the app and create an account, scanning a QR code to activate. Participants then received instructions on how to complete a 60-second PPG recording and add additional symptoms, such as shortness of breath or fatigue. All participants were instructed to perform two measurements daily for 7 days, while seated upright in a steady position. At the end of each measurement, participants received instant feedback on heart rhythm and heart rate, and all tracings were also transferred to a central server for offline analysis. At the end of the week, all participants received a report, and those who received a report detecting AF were recommended to visit their family physician, Vandervoort said.
Across 120,446 PPG signals during the study period, 98,586 were classified as normal rhythms, 9,733 were classified as insufficient quality and 12,127 were classified as possible irregularities that were reviewed by technicians. Among irregular readings, researchers observed 615 traces in which AF was identified in 136 participants (mean age, 62 years; 26% women), including 38 patients with persistent or permanent AF and 98 with paroxysmal AF.
Among those with AF identified via the app, 76% did not report symptoms, Vandervoort said. Overall AF prevalence in the screening population was 1.1%, ranging from less than 0.5% among adults aged 40 to 49 years to 11% among adults aged 80 years and older.
A smartphone app that screens for atrial fibrillation using noninvasive plethysmography is safe and effective in patients.
Source: Adobe Stock
Among 100 of the patients with identified AF who completed a 4-month follow-up survey, 60 had known AF; 43 of those patients remained on the same care path and 17 received a therapy adjustment, Vandervoort said. Among 40 patients with a new diagnosis of AF, 21 had their diagnosis confirmed and 19 did not seek medical attention.
“Using digital technology only, without any need for additional hardware, we can reach large populations very quickly — in less than 48 hours — and collect clinically meaningful data, without the need for any clinical infrastructure,” Vandervoort said. “We didn’t need any ECGs, no doctors or nursing time, and this increased comfort for the patient. They can do measurements anytime, anywhere, and at a fraction of the cost.”
The FibriCheck app studied in DIGITAL-AF is not currently regulated for use in the United States. – by Regina Schaffer
Vandervoort PM. Late-Breaking Science in Telemedicine. Presented at: European Society of Cardiology Congress; Aug. 25-29, 2018; Munich.
Disclosure: Vandervoort reports he receives research grants for conducting validation studies for Qompium.