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OpenTrials
Completed

NCT Number: NCT05207150

Continuous Rhythm Monitoring With Implantable Cardiac Monitors And Wearable Devices With Real-time Smartphone Alerts During AF Episodes

Atrial fibrillation (AF) is the most common arrhythmia affecting 1.3 million people in the UK. AF causes an irregular and fast heartbeat, which makes the heart pump poorly. As a result, blood clots may form inside the heart and, if they travel to the brain, can lead to an AF-related stroke. Patients with AF have a risk of stroke five-times higher than patients with normal rhythm.

Anticoagulants make the blood less likely to clot and, thus, reduce the chances of an AF-related stroke. For most people, once anticoagulation is started it must be taken for the rest of their lives irrespective of the amount of AF someone has. However, anticoagulants make patients more prone to bleeding.

New studies have reported a lower stroke risk in patients with short and infrequent AF episodes. If there are long time gaps in between AF episodes, short periods of anticoagulation around the time of AF may be enough to avoid clots from forming and reducing the overall risk of bleeding. To use anticoagulants only when needed will require an accurate and reliable way to detect AF when it occurs and alert patients. New technologies, such as small heart monitors placed under the skin, watches and rings, can track the heart rhythm continuously and send real-time alerts to patients via mobile phone message if AF is detected.

The purpose of this study is to investigate if implantable cardiac monitors (LINQ II) and wearable devices (Apple Watch and CART-I ring) can detect AF episodes, send real-time alerts to patients and who will respond to these alerts within a short timeframe. The investigators will recruit 50 patients and follow them for six months. All participants will receive a LINQ II and a wearable device.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Oxford Univeristy Hospitals NHS Foundation Trust

Oxford, Oxfordshire, OX89DU, United Kingdom

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Participant is willing and able to give informed consent for participation in the trial.
  • Male or Female aged 18 years or above.
  • Paroxysmal AF with symptoms, Holter recording and/or implantable device evidence of >1 but <15 episodes of AF in the last 3 months.
  • Persistent AF scheduled for repeat cardioversion (i.e. having had at least one prior cardioversion).
  • Currently have an Apple IOS or Android smartphone.

Exclusion criteria

  • Diagnosis of permanent AF.
  • Contra-indications for implantable cardiac monitor.
  • Visual or physical impairment that prevents ability to read and acknowledge smartphone/watch notifications.
  • Unable to comply with the follow-up schedule.
  • Do not have Apple IOS or android smartphone.

Treatment and study plan

LINQII/Apple Watch Series 6

Device

LINQ II will be implanted and in the first 3 months it will send alerts to participants' smartphones if it detects an AF episode longer than 30 minutes. After 3 months, participants will wear an Apple Watch Series 6 for another 3 months. The LINQ II ICM will continue to detect and record AF episodes and will be used to validate the AF detection accuracy by the wearable devices but it will no longer send alerts during AF episodes. Instead, the wearable device (Apple Watch) will send a real-time alert to participants during AF episodes longer than 30 minutes and participants will use the appropriate smartphone app to acknowledge they have received the alert.

LINQII/SkyLabs CART-I ring

Device

LINQ II will be implanted and in the first 3 months it will send alerts to participants' smartphones if it detects an AF episode longer than 30 minutes. After 3 months, participants will wear a SkyLabs CART-I ring for another 3 months. The LINQ II ICM will continue to detect and record AF episodes and will be used to validate the AF detection accuracy by the wearable devices but it will no longer send alerts during AF episodes. Instead, the wearable device (CART-I ring) will send a real-time alert to participants during AF episodes longer than 30 minutes and participants will use the appropriate smartphone app to acknowledge they have received the alert.

Primary outcomes

  1. To assess the performance of the LINQ II™ ICM in sending real-time alerts to participants' smartphone and to Carelink (physicians web portal) during AF episodes longer than 30 minutes

    Time frame: During follow-up (6 months)

    Percentage of successful alerts sent by the LINQII™ ICM.

Secondary outcomes

  1. To study the diagnostic accuracy of the Apple Watch and the Skylabs CART-I ring in the detection of AF episodes .

    Time frame: During the follow-up period (6 month)Apple Watch and Skylabs CART-I ring sensitivity, specificity, positive and negative predictive for AF episodes longer than 30 minutes.

    Apple Watch and Skylabs CART-I ring diagnostic accuracy for AF episodes longer than 30 minutes compared to the LINQ II™ ICM (gold standard).

  2. To assess the performance of the Apple Watch and the Skylabs CART-I ring in sending real-time alerts to their smartphone apps and participants' engagement.

    Time frame: During follow-up (6 months)

    Percentage of successful alerts sent by the Apple Watch and Skylabs CART-I ring.

  3. To study participants' compliance wih the Apple Watch and the Skylabs CART-I ring

    Time frame: During follow-up (6 months)

    Percentage of time the wearable devices have been used and comparison between different modalities will be calculated.

Sponsors and collaborators

Lead sponsor

Oxford University Hospitals NHS Trust

Other

Registry information

Acronym: SMART-ALERT

Important dates

Study start
2021
Primary completion
2022
Study completion
2023
First posted
Jan 26, 2022
Registry last updated
Aug 8, 2023

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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