“Atrial fibrillation detection with smartphone cameras and wearables – Results of the DETECT AF PRO and WATCH AF trials”
Jens ECKSTEIN (Basel, Switzerland)
During the late-breaking science sessions, at the 2018 annual conference of the European Heart Rhythm Association in Barcelona, Jens Eckstein has presented results of the WATCH AF trial for the first time. It is the world’s first international, prospective and double-blinded clinical trial (ClinicalTrials.gov ID: NCT02956343) evaluating the accuracy of a smartwatch to detect atrial fibrillation. Preventicus, a German based company, provided the application for blinded analysis of 1 minute plethysmographic raw data (recorded with Samsung Gear Fit II smartwatch) of 636 study participants. Total accuracy of the application was 95.7% with a positive predictive value of 97.8% in comparison to the ECG based diagnosis of two cardiologists by mutual agreement.
The smartwatch application “Preventicus Nightwatch®” incorporates that algorithm. It can continuously 24/7 analyze plethysmographic raw data and document AF events lasting at least 1 minute. The application will be launched in Europe as a certified medical device.
The same AF detection algorithm is already available in a smartphone camera application (“Preventicus® Heartbeats”, a CE marked medical device in the EU). The results of the corresponding DETECT AF PRO trial (ClinicalTrials.gov ID: NCT02949180) were introduced for the first time in the same session. DETECT AF PRO is a separate trial from WATCH AF and is a prospective, double-blinded, international study as well with 672 participants. Total accuracy of the smartphone camera application to detect AF was 96.5% with a positive predictive value of 99.3% compared to the ECG based diagnosis of two cardiologists by mutual agreement.
How are AF events captured by smartwatches or smartphones accessible to Medical Professionals?
All detected AF events are accessible on a dedicated ICT platform, allowing medical professionals to oversee their patients using the new technology. The Preventicus algorithm analyses every single heartbeat recorded and classifies it as regular or irregular. The resulting report enables medical professionals to beat by beat comprehend the recorded events.
Why screening of AF with smart devices makes sense and why it helps to prevent strokes?
Stroke is the second most cause of death and is strongly associated with undetected or untreated AF – the most common sustained cardiac arrhythmia. AF may come and go and is often not noticed (silent AF). Its sporadic occurrence is the main reason why it is so difficult to capture. Chances to detect sporadic AF with „classic” methods (e.g. 24h-Holter-ECG) are around 25% only. It is estimated that every ten seconds a stroke happens in combination with unknown or untreated AF. Only when AF is detected and confirmed, e.g. pharmaceutical treatment can be started and stroke rate can be significantly reduced. This is why smartwatches and smartphone camera applications now aim to close a gap. They are considered as new AF screening tools in a recent EHRA consensus statement and make AF population screening – to prevent strokes – available to patients and medical professionals.
Further information here.