An interventional study of CardioWatch 287-2 Group and Control Group in Atrial Fibrillation (AF), sponsored by Medical University of Graz. Not yet recruiting at 1 site in Austria. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Medical University of Graz · Not applicable, Interventional, and Diagnostic
Early detection of atrial fibrillation detected after stroke (AFDAS) is crucial for secondary stroke prevention, as initiating direct oral anticoagulants (DOACs) can reduce atrial fibrillation (AF)-related stroke risk by up to 60%. In cryptogenic stroke (CS), AFDAS likely represents the most frequent underlying etiology, yet paroxysmal and short-duration AF episodes often elude standard monitoring. The Graz AF Risk Score, implemented across all Neurology Departments in Styria, Austria, stratifies patients into tailored monitoring pathways but remains limited by delays in implantable loop recorder (ILR) implantation, patient refusal, and restricted access to early ambulatory ECG monitoring.
The study aims to close diagnostic gaps in the current AF detection pathway by implementing a non-invasive, wrist-worn photoplethysmography (PPG) device (i.e., CardioWatch 287-2 [CW2]) for early cardiac rhythm monitoring in CS patients.
Methods:
CATCH-AF is an investigator-initiated, prospective, longitudinal, multi-center, pre-post interventional study including all CS patients admitted to one of five Styrian Neurology Departments. In the pre-intervention phase, AF detection will follow the established Graz AF Risk Score-based algorithm. In the intervention phase, CardioWatch 287-2 screening will replace Holter-ECG screening in moderate-risk patients and will be used for high-risk patients with delayed or declined ILR implantation. Suspected AF episodes will be confirmed by ECG- based assessment at the discretion of the treating cardiologist. The primary endpoint isAFDAS detection at 3 months; secondary endpoints include AFDAS at 12 months, time to AF detection and DOAC initiation, cerebrovascular event recurrence, cardiovascular death, and all-cause mortality at 3 and 12 months. Data will be collected via REDCap and analyzed using descriptive, univariable, and multivariable regression methods, adjusted for confounders with inverse probability of treatment weighting.
The investigators hypothesize that CardioWatch 287-2 implementation will increase early AFDAS detection and reduce diagnostic and therapeutic delays, potentially lowering recurrent cerebrovascular events and mortality over 12 months.
CATCH-AF represents the first European, population-wide evaluation of a wrist-worn PPG device integrated into an established AF detection pathway for cryptogenic stroke, aiming to improve early diagnosis, treatment initiation and secondary prevention outcomes.
Background:
The early identification of atrial fibrillation detected after stroke (AFDAS) is essential to optimize secondary stroke prevention, as the initiation of direct oral anticoagulants (DOACs) reduces atrial fibrillation (AF)-related stroke risk by up to 60%. However, AFDAS often occurs paroxysmal and in short episodes, which complicates its detection. In acute ischemic stroke of undetermined source after the initial workup (=cryptogenic stroke, CS), AFDAS may represent the most frequent etiology. Randomized clinical trials (NAVIGATE ESUS, RESPECT ESUS, ATTICUS) failed to demonstrate superiority of treating unselected CS patients with direct oral anticoagulants (DOACs) compared to standard antiplatelet treatment. Moreover, the recently published ARCADIA trial was not able to identify a reduction in recurrent ischemic stroke using Apixaban in cryptogenic stroke patients with echocardiographic and/or laboratory signs of atrial cardiopathy.
These results support the necessity for detecting AF in CS patients, but costs and availability in daily clinical routine represent barriers in the use of prolonged cardiac rhythm monitoring.
Therefore, a clinical risk score based on electrocardiographic, echocardiographic, neuroimaging, and blood biomarkers (Graz AF Risk Score) was developed and implemented across all hospitals in the Province of Styria, Austria, which collectively provide care for more than 2,000 stroke patients annually. The score, routinely applied within the first days after admission, determines the subsequent AF detection strategy. Patients with low scores (0-1 points) do not undergo further cardiac rhythm monitoring (negative predictive value: >99%). Those with scores of 2 or 3 receive further ambulatory ECG monitoring of at least 24 hours, while patients with scores ≥4 are offered an implantable loop recorder.
To the best of our knowledge, this is the largest continuously evaluated AF detection pathway of CS patients in Europe. Despite its success in improving AF identification rates, recent findings highlight important limitations.
Limitations of present diagnostic pathway
The present pathway is constrained by significant limitations:
Delay to monitoring start:
Although implantation of implantable loop recorders is typically recommended during hospital stay, delays of more than 7 days are often observed. A recent pooled-data analysis conducted by our group in collaboration with the international multicenter BIOSIGNAL study (Hatab I, Kneihsl M, STROKE 2025) highlighted the importance of early AFDAS detection. Closing the diagnostic gap using more readily available and applicable tools, such as the CardioWatch 287-2 (CW2), could significantly improve early AF detection rates.
Refusal of implantable devices:
Based on our data, one in every five patients declines loop recorder implantation, opting instead for non-invasive monitoring techniques. However, in daily clinical practice, access to alternatives that monitor for at least 24 hours is limited. Therefore, non-invasive and more easily available monitoring tools capable of cardiac rhythm monitoring are needed to improve AFDAS detection.
According to the Graz AF Risk score, individuals with scores of 2 to 3 points undergo prolonged cardiac rhythm monitoring through ambulatory ECG monitoring of at least 24 hours. However, early availability is limited, which might reduce its effectiveness for early AFDAS detection.
Aims and hypothesis Primary aims and hypotheses The primary objective of this project (CATCH AF) is to improve AFDAS detection in CS patients by closing the diagnostic gaps using a non-invasive easily applicable cardiac rhythm monitoring tool, i.e. the CardioWatch 287-2 (CW2).
Secondary aims and hypotheses As secondary objectives, we aim
Clinical innovation of the project To the best of our knowledge, this proposed project would be the first to utilize a wrist-worn photoplethysmography (PPG) device for cardiac rhythm monitoring (i.e., CardioWatch 287-2 (CW2), as an adjunct to close diagnostic gaps in AFDAS detection.
Furthermore, the project will employ an internationally recognized diagnostic pathway that is under continuous evaluation. This unique approach allows for a pre- and post-analysis, with the CardioWatch 287-2 (CW2) serving as the intervention. It will provide valuable insights into the benefits of using additional devices to improve AFDAS detection rates and reduce diagnostic delays.
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 1,500 is above the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →Medical University of Graz is the lead sponsor of 471 studies on the registry; 98 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
During the pre-interventional observation period, all participating Neurology Departments will continue their routine clinical care without implementing any additional study-specific AF-detection measures. This includes in-depth investigation of stroke etiology using a guideline-based thorough and standardized diagnostic workup including brain imaging (mostly MRI), ultrasound and / or MRI-based investigation of brain-supplying vessels, electrocardiogram (ECG), ECG-monitoring for 48 hours and echocardiography. In patients whose stroke etiology remains cryptogenic after the guideline-based work-up, prolonged cardiac rhythm monitoring is based on a uniform algorithm including a clinical risk score (i.e., Graz AF Risk Score) as proposed by Kneihsl et al. in 2022 and which has already been established in all Neurology Departments of the Province of Styria, Austria.
Device: Control Group
To close diagnostic gaps of the present diagnostic pathway (i.e., Delay to ECG-Holter monitoring start, Refusal of implantable devices) the CardioWatch 287-2 (CW2) will be implemented as wearable PPG based diagnostic tool to identify AF in CS patients in all five Styrian Neurology Departments.
Device: CardioWatch 287-2 Group
* Low Risk (Graz AF Risk Score: 0-1 points, negative predictive value: \>99%): No additional monitoring will be done * Moderate Risk (Graz AF Risk Score: 2-3 points): CardioWatch 287-2 (CW2) will be used in all patients whose stroke etiology remains cryptogenic after the initial work-up instead of Holter-ECG. * High Risk (Graz AF Risk Score: \>= 4 points): An implantable loop recorder implantation will be offered. If there is a delay of more than 7 days before implantation, or if the patient refuses the procedure, a CardioWatch 287-2 (CW2) will be used instead of the Holter-ECG.
* Low Risk (Graz AF Risk Score: 0-1 points, negative predictive value: \>99%): No additional monitoring will be done * Moderate Risk (Graz AF Risk Score: 2-3 points): An ambulatory Holter-ECG of at least 24 hours will be used to monitor for covert AF * High Risk (Graz AF Risk Score: \>= 4 points): An implantable loop recorder implantation will be offered. If there is a delay of more than 7 days before implantation, or if the patient refuses the procedure, a Holter-ECG of at least 24 hours will be used instead.
Occurrence of atrial fibrillation detected after stroke (AFDAS) within 3 months post-stroke
Proportion of participants with AFDAS detected within 3 months after the index stroke. Define AFDAS according to the study protocol. Unit of Measure: Participants / %
Time frame: 3 months post-stroke
Occurrence of AFDAS within 12 months post-stroke
Proportion of participants with AFDAS detected within 12 months after the index stroke. Unit of Measure: Participants / %
Time frame: 12 months after index stroke
Time to first AFDAS detection
Time from the index stroke to first documented detection of AFDAS. Unit of measure: Days
Time frame: Up to 12 months after index stroke
Time to initiation of direct oral anticoagulant (DOAC) therapy
Time from the index stroke to initiation of DOAC therapy. Specify the analysis population according to the protocol. Unit of measure: Days
Time frame: Up to 12 months after index stroke
Occurrence of recurrent ischemic stroke within 3 months post-stroke
Proportion of participants experiencing recurrent ischemic stroke within 3 months after the index stroke. Unit of measure: Participants / %
Time frame: 3 months after the index stroke
Occurrence of myocardial infarction within 3 months post-stroke
Proportion of participants experiencing myocardial infarction within 3 months after the index stroke. Unit of measure: Participants / %
Time frame: 3 months after the index stroke
Occurrence of acute peripheral arterial occlusion within 3 months post-stroke
Proportion of participants experiencing acute peripheral arterial occlusion within 3 months after the index stroke. Unit of measure: Participants / %
Time frame: 3 months after the index stroke
Occurrence of recurrent ischemic stroke within 12 months post-stroke
Proportion of participants experiencing recurrent ischemic stroke within 12 months after the index stroke. Unit of measure: Participants / %
Time frame: 12 months after the index stroke
Occurrence of myocardial infarction within 12 months post-stroke
Proportion of participants experiencing myocardial infarction within 12 months after the index stroke. Unit of measure: Participants / %
Time frame: 12 months after the index stroke
Occurrence of acute peripheral arterial occlusion within 12 months post-stroke
Proportion of participants experiencing acute peripheral arterial occlusion within 12 months after the index stroke. Unit of measure:
Time frame: 12 months after the index stroke
Cardiovascular mortality within 3 months post-stroke
Proportion of participants who die from a cardiovascular cause within 3 months after the index stroke. Unit measure: Participants / %
Time frame: 3 months after the index stroke
Cardiovascular mortality within 12 months post-stroke
Proportion of participants who die from a cardiovascular cause within 12 months after the index stroke. Unit of measure: Participants / %
Time frame: 12 months after the index stroke
All-cause mortality within 3 months post-stroke
Proportion of participants who die from any cause within 3 months after the index stroke. Unit of measure: Participants / %
Time frame: 3 months after the index stroke
All-cause mortality within 12 months post-stroke
Proportion of participants who die from any cause within 12 months after the index stroke. Unit of measure: Participants / %
Time frame: 12 months after the index stroke
Start is estimated for Oct 2026; primary completion for Aug 2029, 34 months later.
Of 796 non-industry interventional studies with no phase under Atrial Fibrillation, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 34 months is below that.
Counting every sponsor, half of 1,051 studies reached it within 33 months; a quarter within 18 and three quarters within 54.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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