Clinical Trial 44840

Fort Lauderdale, FL 33073


SYNOPSIS. Study Protocol CV185-749

Protocol Title: GUARD-AF: reducinG stroke by screening for UndiAgnosed atRial fibrillation in elderly inDividuals

Objective: To determine if an AF detection intervention in men and women at least 70 years of age with undiagnosed AF or AFL reduces the person-years incidence rate of stroke compared to usual care (no AF detection intervention).

Study Design: Prospective, randomized study in approximately 300 primary care practices. Eligible participants will be randomized 1:1 to the AF detection intervention for up to 14 days from randomization with a single-lead ECG monitor (Zio®XT monitor) or usual care (no Zio ®XT monitor). Appendix 1 shows a diagram of the Zio®XT monitor.

The study has two options for enrolling eligible participants:

(1) Enrollment on-site involves informed consent, randomization, and application of the Zio®XT monitor for those randomized to the monitor.

(2) Virtual enrollment involves obtaining virtual informed consent, randomization, and applying the Zio®XT monitor at home for those randomized to the monitor. The primary endpoints of stroke leading to hospitalization and bleeding leading to hospitalization will be ascertained by linking each participant’s Medicare Beneficiary Identifier (MBI) to Medicare Parts A and B research-identifiable inpatient and outpatient claims. Ascertainment of these endpoints does not require clinical follow up of participants by sites. The timelines for the study assume that: (1) 52,000 participants will be enrolled in approximately 1 year and (2) The design of the study is based on accrual of at least 800 strokes. Accordingly, the number of strokes will be assessed at 2.5 years after the start of the study. If necessary, the duration to ascertain strokes and bleeding by use of MBIs could be extended up to a maximum of 5 years after the first participant is randomized (See Section 7).

To facilitate enrollment in the study, medical records will be reviewed to identify eligible patients. Patients from participating primary care practices who meet eligibility requirements will be offered the opportunity to participate in the study.

At enrollment, the study will be explained to the patient and informed consent will be obtained following which patients will be randomized 1:1 to the AF detection intervention or usual care. Participant’s baseline characteristics and Personal Health Information (PHI: year of birth, gender and MBI) will be entered into the eCRF.

Participants randomized to the usual care arm will get the same care that they would receive if not enrolled in the study. Participants randomized to the AF detection intervention will have a Zio® XT monitor affixed to his or her chest after enrollment. Participants wear the Zio® XT monitor for up to 14 days during which a single-lead ECG is recorded continuously and stored in the device. After approximately 14 days, participants remove the device, place it in its postage-paid package, and mail it to iRhythm Technologies, Inc. (San Francisco, CA) for analysis. Within 5-7 days after the device is received, iRhythm analyzes the recordings and generates an AF/AFL Outcomes Summary. Sites will be notified when the Summary is available for review on the iRhythm website. The Summary can be digitally downloaded and printed. The Summary will be provided electronically to the Sponsor to incorporate into the study database. The Investigator will confirm in the eCRF that he or she has reviewed the AF/AFL Outcome Summary. Appendix 2 provides guidance on an approach to reducing the risk of stroke associated with AF/AFL.


1. Men and women at least 70 years of age who are new or established patients in the primary care practice

2. Willing to provide consent to participate in the study and to use personal health information to ascertain endpoints from the CMS Medicare Claims Database and to access data from health records

3. Health insurance by Medicare Parts A & B (Medicare Fee-for-service)


Qualified Participants May Receive:

Informed concent form

Financial compensation

Device to monitor heart rate throughout the course of the study


Available At:

Pinnacle Research Institute
2900 West Cypress Creek Road, Suite 13
Fort Lauderdale, FL 33073
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Clinical trials are medical research studies designed to test the safety and/or effectiveness of new investigational drugs, devices, or treatments in humans. These studies are conducted worldwide for a range of conditions and illnesses. Learn more about clinical research and participating in a study at About Clinical Trials.