Cardiac ArrhythmiaNCT07205367
Validation Study: Extended Wear Performance of the Zio Monitor - SHASTA II
A study testing Zio Monitor in people with Cardiac Arrhythmia, run by iRhythm Technologies, Inc. at 2 sites in United States.
Trial summary
This trial assesses the wear performance of the Zio monitor, a long-term continuous ambulatory patch ECG monitor, in a representative population by evaluating (1) the wear duration (up to 30 days) of the device, (2) the percentage of analyzable electrocardiographic time and (3) safety by reviewing all adverse events. Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Cardiac Arrhythmia
- What is being tested?
- Zio Monitor
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 150 participants
- Where
- 2 sitesUnited States
- Study dates
- 6 Jan 2025to 7 Nov 2025
- Phase
- Interventional
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Participant must be 18 years or older at time of informed consent.
- Participant is willing and able to provide informed consent and be able to complete all visits for the study.
Who cannot join
- Participant has a known allergy to adhesives.
- Participant has a current skin infection or injury at location for study device placement.
- Participant is a member of a vulnerable population.
- Participant is a current or prior employee of iRhythm.
- Participant is unable or unwilling to participate or comply with study protocol.
- The local Investigator deems the participant has a condition that could limit the participant's ability or willingness to participate in the study, or ability to comply with study required procedures and/or follow-up visits.
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- Participant has experienced symptomatic episodes where instance variations in cardiac performance could result in immediate danger to the participant.
- Participant has an external cardiac defibrillator or may be exposed to high frequency surgical equipment near strong magnetic fields or devices such as MRI during the wear period.
- Participant has a neuro-stimulator, as it may disrupt the quality of ECG data.
- Participant does not have the competency to wear the device for the prescribed monitoring period.
- Participant does not have the ability to consent for themselves (i.e., no LARs).
Trial locations and contacts
2 sites in 1 country.
United States2 sites
iRhythm Technologies - Deerfield, IL
Deerfield, Illinois, 60015
iRhythm Technologies - San Francisco, CA
San Francisco, California, 94103
About this study
This trial assesses the wear performance of the Zio monitor, a long-term continuous ambulatory patch ECG monitor, in a representative population by evaluating (1) the wear duration (up to 30 days) of the device, (2) the percentage of analyzable electrocardiographic time and (3) safety by reviewing all adverse events.
Read the detailed description
This is a prospective, multi-center, single-arm study to validate the design of the Zio monitor/Zio MCT device form factor in extended (21-day) wear when utilizing an updated skin prep process.
The trial is conducted in 2 phases. Phase I includes the standard skin preparation process of 40 strokes with an exfoliator in 4 different directions. Phase II incorporates a modified skin preparation process: only 20 strokes with an exfoliator in 2 directions are used. There are 75 participants in each phase.
Performance objectives include the following: (1) Mean wear duration of 21 days and (2) percent analyzable time of 80%.
Safety measures include the proportion of participants that experience clinically significant skin irritation through 30 days of wear, as well as the reporting of all adverse events.
Additional device measures include the following: (1) % signal artifact (defined as the proportion of ECG signal that is artifact over the wear duration, reported for each study device); (2) % device functionality (defined as the proportion of Zio monitors recording a continuous ECG signal through 21 days, and through 30 days) and (3) observational assessment of participant skin types (assessed by dryness levels, hyperhydrosis status, Fitzpatrick Skin Type and chest hair density).
All analyses will be performed on the population of enrolled participants on whom the Zio monitor application was attempted. The age, sex at birth, and application type (i.e., healthcare provider (HCP) designee vs. self-application) of participants will be monitored throughout the enrollment period to ensure representation across key user groups. Performance within subgroups including (but not limited to) sex at birth, age, and application type will be assessed.
Seventy-five (75) participants in Phase I and 75 participants in Phase II will be enrolled at 2 US iRhythm locations (San Francisco, CA and Deerfield, IL).
There are 3 on-location visits at Baseline (Visit 1/time of patch application), Day 21 (Visit 4) and Day 30 (Visit 5/following 30 days of patch application). There are 2 telephone/video calls at Day 7 (Visit 2) and Day 14 (Visit 3).
Participants who meet all inclusion criteria and no exclusion criteria will be enrolled.
- Conditions
- Cardiac Arrhythmia
- Being tested
- Zio Monitor
- Medical subject headings
- Arrhythmias, Cardiac
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Zio MonitorDevice
The Zio monitor is a long-term continuous ambulatory patch ECG monitor which adheres to the patient's left pectoral region.
| Study group | Role | What they receive |
|---|---|---|
| Open Label - Phase I Participants | Other | This is an open-label study conducted in 2 phases. All participants (75 in Phase I) will have the study device applied to their chest. Two-thirds of the participants will have the study device applied by a Study Staff member (i.e., Healthcare Provider (HCP)). One-third of the participants will self-apply the study device to their chest (i.e., simulated at-home patch application). Application of all study devices will be performed at the site. Receives: Device: Zio Monitor |
| Open Label - Phase II Participants | Other | This is an open-label study conducted in 2 phases. All participants (75 in Phase II) will have the study device applied to their chest. Two-thirds of the participants will have the study device applied by a Study Staff member (i.e., Healthcare Provider (HCP)). One-third of the participants will self-apply the study device to their chest (i.e., simulated at-home patch application). Application of all study devices will be performed at the site. Receives: Device: Zio Monitor |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean Wear Duration
This outcome measure is met if the mean wear duration is greater than 21 days
Measured: 21 - 30 days after baseline
Percent Analyzable Time
This outcome measure is met if the percent analyzable time is greater than 80% in 90% of subjects.
Measured: Up to 30 days (Day 30)
Safety: Skin Irritation
This includes the proportion of participants that experience clinically significant skin irritation through 30 days of wear. This will be assessed through the capture and reporting of all adverse events.
Measured: Up to 30 days (Day 30)
Secondary outcomes (6)
Additional Device Measure 1: Signal Artifact
Percent signal artifact is defined as the proportion of ECG signal that is artifact over the wear duration, reported for each study device. Signal artifact is a continuous value representing the percentage of the wear duration that was not interpretable. This variable will be calculated as the inverse of analyzable ECG percent. Signal artifact will be summarized using the population meeting protocol requirements and include means and 95% confidence intervals for these proportions.
Measured: Up to 30 days (Day 30)
Additional Device Measure 2: Device Functionality
Device functionality is defined as the number of participants with Zio monitors recording a continuous ECG signal through 21 and 30 days. The ability to record a continuous ECG signal is defined as device functionality. Device functionality will be determined by the number of participants with devices adhering to the skin, the number of participants with devices functioning/operating and the number of participants with devices that are recording and ECG signal.
Measured: At 21 days (Day 21) and 30 days (Day 30)
Observational Assessment: Skin Dryness Level
This includes an assessment of the following skin types: dry, oily and normal.
Measured: Baseline (Day 1)
Observational Assessment: Hyperhydrosis Status
This includes an assessment of the following hyperhydrosis status: primary, secondary or none.
Measured: Baseline (Day 1)
Observational Assessment: Fitzpatrick Skin Type
This includes a 6-point scale to assess the following skin types: (1) pale skin; always burns, never tans; (2) fair skin; usually burns, tans minimally; (3) darker white skin; sometimes mild burn, tans uniformly; (4) light brown skin; burns minimally, always tans well; (5) brown skin; very rarely burns; tans very easily; (6) dark brown or black skin; never burns.
Measured: Baseline (Day 1)
Observational Assessment: Chest Hair Density
This includes an assessment of the following chest hair density types: smooth/no hair; some hair; moderately hairy; or very hairy in the target patch placement area.
Measured: Baseline (Day 1)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Oct 2025
- Study start6 Jan 2025
- Primary completion29 Jul 2025
- Study completion7 Nov 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for Cardiac ArrhythmiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- This is a design validation study to evaluate the wear performance of the Zio monitor/Zio MCT device form factor.
- Masking
- None (open label)
- Enrolment
- 150 participants (actual)
Sponsor and investigators
- Lead sponsor
- iRhythm Technologies, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07205367
- Sponsor's protocol ID
- iRT-003-2024
- Status last verified
- Aug 2026
- First submitted
- 9 Sep 2025
- Last updated
- 5 Aug 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- Yes
- Individual data sharing
- No: Individual participant data will not be available to other researchers.
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Validation Study: Extended Wear Performance of the Zio Monitor - SHASTA II
- ClinicalTrials.gov ID
- NCT07205367
- Acronym / sponsor ID
- iRT-003-2024
- Conditions
- Cardiac Arrhythmia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 150 participants (actual)
- Lead sponsor
- iRhythm Technologies, Inc.Industry (pharma, biotech, devices)
- Study start
- 6 Jan 2025 (actual)
- Primary completion
- 29 Jul 2025 (actual)
- Study completion
- 7 Nov 2025 (actual)
- First posted
- 3 Oct 2025 (actual)
- Results
- Posted 5 Aug 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This trial assesses the wear performance of the Zio monitor, a long-term continuous ambulatory patch ECG monitor, in a representative population by evaluating (1) the wear duration (up to 30 days) of the device, (2) the percentage of analyzable electrocardiographic time and (3) safety by reviewing all adverse events.
Detailed description
This is a prospective, multi-center, single-arm study to validate the design of the Zio monitor/Zio MCT device form factor in extended (21-day) wear when utilizing an updated skin prep process.
The trial is conducted in 2 phases. Phase I includes the standard skin preparation process of 40 strokes with an exfoliator in 4 different directions. Phase II incorporates a modified skin preparation process: only 20 strokes with an exfoliator in 2 directions are used. There are 75 participants in each phase.
Performance objectives include the following: (1) Mean wear duration of 21 days and (2) percent analyzable time of 80%.
Safety measures include the proportion of participants that experience clinically significant skin irritation through 30 days of wear, as well as the reporting of all adverse events.
Additional device measures include the following: (1) % signal artifact (defined as the proportion of ECG signal that is artifact over the wear duration, reported for each study device); (2) % device functionality (defined as the proportion of Zio monitors recording a continuous ECG signal through 21 days, and through 30 days) and (3) observational assessment of participant skin types (assessed by dryness levels, hyperhydrosis status, Fitzpatrick Skin Type and chest hair density).
All analyses will be performed on the population of enrolled participants on whom the Zio monitor application was attempted. The age, sex at birth, and application type (i.e., healthcare provider (HCP) designee vs. self-application) of participants will be monitored throughout the enrollment period to ensure representation across key user groups. Performance within subgroups including (but not limited to) sex at birth, age, and application type will be assessed.
Seventy-five (75) participants in Phase I and 75 participants in Phase II will be enrolled at 2 US iRhythm locations (San Francisco, CA and Deerfield, IL).
There are 3 on-location visits at Baseline (Visit 1/time of patch application), Day 21 (Visit 4) and Day 30 (Visit 5/following 30 days of patch application). There are 2 telephone/video calls at Day 7 (Visit 2) and Day 14 (Visit 3).
Participants who meet all inclusion criteria and no exclusion criteria will be enrolled.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This is a design validation study to evaluate the wear performance of the Zio monitor/Zio MCT device form factor.
| Arm | Type | Receives |
|---|---|---|
| Open Label - Phase I Participants | Other | Device: Zio MonitorThis is an open-label study conducted in 2 phases. All participants (75 in Phase I) will have the study device applied to their chest. Two-thirds of the participants will have the study device applied by a Study Staff member (i.e., Healthcare Provider (HCP)). One-third of the participants will self-apply the study device to their chest (i.e., simulated at-home patch application). Application of all study devices will be performed at the site. |
| Open Label - Phase II Participants | Other | Device: Zio MonitorThis is an open-label study conducted in 2 phases. All participants (75 in Phase II) will have the study device applied to their chest. Two-thirds of the participants will have the study device applied by a Study Staff member (i.e., Healthcare Provider (HCP)). One-third of the participants will self-apply the study device to their chest (i.e., simulated at-home patch application). Application of all study devices will be performed at the site. |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Participant must be 18 years or older at time of informed consent.
- Participant is willing and able to provide informed consent and be able to complete all visits for the study.
Key exclusion criteria (11 listed)
- Participant has a known allergy to adhesives.
- Participant has a current skin infection or injury at location for study device placement.
- Participant is a member of a vulnerable population.
- Participant is a current or prior employee of iRhythm.
- Participant is unable or unwilling to participate or comply with study protocol.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Zio MonitorThe Zio monitor is a long-term continuous ambulatory patch ECG monitor which adheres to the patient's left pectoral region. | Device | Open Label - Phase I Participants, Open Label - Phase II Participants |
Primary outcome
Mean Wear Duration
Time frame: 21 - 30 days after baseline
This outcome measure is met if the mean wear duration is greater than 21 days
Percent Analyzable Time
Time frame: Up to 30 days (Day 30)
This outcome measure is met if the percent analyzable time is greater than 80% in 90% of subjects.
Safety: Skin Irritation
Time frame: Up to 30 days (Day 30)
This includes the proportion of participants that experience clinically significant skin irritation through 30 days of wear. This will be assessed through the capture and reporting of all adverse events.
6 secondary outcomes
Additional Device Measure 1: Signal Artifact
Time frame: Up to 30 days (Day 30)
Additional Device Measure 2: Device Functionality
Time frame: At 21 days (Day 21) and 30 days (Day 30)
Observational Assessment: Skin Dryness Level
Time frame: Baseline (Day 1)
Observational Assessment: Hyperhydrosis Status
Time frame: Baseline (Day 1)
Observational Assessment: Fitzpatrick Skin Type
Time frame: Baseline (Day 1)
Observational Assessment: Chest Hair Density
Time frame: Baseline (Day 1)
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: No. Individual participant data will not be available to other researchers.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Zio Monitor in people with Cardiac Arrhythmia, run by iRhythm Technologies, Inc. at 2 sites in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 5 Aug 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean Wear Duration (time frame: 21 - 30 days after baseline). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026.