Trial Outcomes & Findings for American Heart Association- Stroke/Hypoxia Study (NCT NCT04019522)
NCT ID: NCT04019522
Last Updated: 2026-04-07
Results Overview
All adverse events will be reviewed for safety and study continuation by the medical monitor.
Recruitment status
COMPLETED
Study phase
NA
Target enrollment
16 participants
Primary outcome timeframe
6 days
Results posted on
2026-04-07
Participant Flow
Participant milestones
| Measure |
Hypoxia
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Screening
STARTED
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16
|
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Screening
COMPLETED
|
12
|
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Screening
NOT COMPLETED
|
4
|
|
Interventions
STARTED
|
12
|
|
Interventions
COMPLETED
|
10
|
|
Interventions
NOT COMPLETED
|
2
|
Reasons for withdrawal
| Measure |
Hypoxia
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Screening
Withdrawal by Subject
|
2
|
|
Screening
Physician Decision
|
2
|
|
Interventions
Lost to Follow-up
|
1
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Interventions
Physician Decision
|
1
|
Baseline Characteristics
American Heart Association- Stroke/Hypoxia Study
Baseline characteristics by cohort
| Measure |
Hypoxia
n=12 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Age, Continuous
|
59.75 years
STANDARD_DEVIATION 6.4 • n=527 Participants
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|
Sex: Female, Male
Female
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2 Participants
n=527 Participants
|
|
Sex: Female, Male
Male
|
10 Participants
n=527 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
0 Participants
n=527 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
12 Participants
n=527 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=527 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=527 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=527 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=527 Participants
|
|
Race (NIH/OMB)
Black or African American
|
9 Participants
n=527 Participants
|
|
Race (NIH/OMB)
White
|
3 Participants
n=527 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=527 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
0 Participants
n=527 Participants
|
|
Region of Enrollment
United States
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12 participants
n=527 Participants
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|
Chedoke McMaster Hand Score
|
4.5 units on a scale
STANDARD_DEVIATION 1.83 • n=527 Participants
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|
Time since Stroke Onset
|
9.03 years
STANDARD_DEVIATION 7.16 • n=527 Participants
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PRIMARY outcome
Timeframe: 6 daysAll adverse events will be reviewed for safety and study continuation by the medical monitor.
Outcome measures
| Measure |
Hypoxia
n=12 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Number of Participants With Adverse Events
Heart Rate below 50 beats per minute at baseline · Participants with this adverse event
|
2 Participants
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|
Number of Participants With Adverse Events
Elevated blood pressure at baseline · Participants with this adverse event
|
1 Participants
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|
Number of Participants With Adverse Events
Elevated blood pressure at baseline · Participants without this adverse event
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11 Participants
|
|
Number of Participants With Adverse Events
Heart Rate below 50 beats per minute at baseline · Participants without this adverse event
|
10 Participants
|
|
Number of Participants With Adverse Events
Claustrophobia · Participants with this adverse event
|
1 Participants
|
|
Number of Participants With Adverse Events
Claustrophobia · Participants without this adverse event
|
11 Participants
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SECONDARY outcome
Timeframe: Baseline and Day 6is a tool used by healthcare providers to objectively quantify the impairment caused by a stroke. The NIHSS is composed of 11 items, each of which scores a specific ability between a 0 and 4. For each item, a score of 0 typically indicates normal function in that specific ability, while a higher score is indicative of some level of impairment. The individual scores from each item are summed in order to calculate a patient's total NIHSS score ranging from 0-44. A change from baseline to follow up 1 (day 6) is reported, calculated from: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=10 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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National Institute of Health Stroke Scale (NIHSS)
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-0.3 Change in score on scale
Standard Deviation 1.9
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SECONDARY outcome
Timeframe: Baseline, Day 6Each test element will be graded on a 3-point ordinal scale and summed up to provide a maximum upper limb score of 66. Reliability and validity have been demonstrated. The FMA will be administered while the subject is seated. A score of 0 indicates no upper extremity function or reflexes, a score of 66 indicates complete control of the paretic upper extremity. The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=10 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Fugl- Meyer Assessment
|
-1.6 Change in score on a scale
Standard Deviation 4.7
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SECONDARY outcome
Timeframe: Baseline, Day 6This scale allows for characterization of increases in muscle tone, from low or normal tone to complete limb rigidity. Specifically, we will evaluate the elbow flexors, bilaterally. A score of zero indicates no residual muscle spasticity, a score of 4 is a completely rigid limb with no possible movement. Each participant had their stroke affected elbow joint tested. The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=10 Elbow Flexors
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Modified Ashworth Scale
|
-0.1 Change in score on a scale
Standard Deviation 0.7
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SECONDARY outcome
Timeframe: Baseline, Day 6Population: Each of a participant's two hands were analyzed separately, Stroke primarily affects one side of the body more than the other, so we are reporting both hands separately.
A dynamometer measures maximum gross grasp (lb.) averaged over three attempts with each hand. The minimum possible value of zero lb. will be assigned when the participant cannot actively flex the fingers or grasp the dynamometer. Completed bilaterally, if possible The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=20 Hands
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Grip Strength
Affected Hand
|
4.38 Change in Pounds
Standard Deviation 7.6
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Grip Strength
Less Affected Hand
|
1.6 Change in Pounds
Standard Deviation 10.8
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SECONDARY outcome
Timeframe: Baseline, Day 6Population: Each participant performed the assessment with each hand, stroke typically affects one side more than the other, so we are reporting each hand separately
Hydraulic Handheld Dynamometer): A dynamometer measures maximum gross grasp (lb.) averaged over 3 attempts with each hand. The minimum possible value of zero lb. will be assigned when the participant cannot actively flex the fingers or grasp the dynamometer. The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=20 Hands
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Pinch Strength
Affected Hand
|
1.7 Change in Pounds
Standard Deviation 3.5
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Pinch Strength
Less Affected Hand
|
2.1 Change in Pounds
Standard Deviation 3.2
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SECONDARY outcome
Timeframe: Baseline, Day 6Population: Each participant performed the assessment with each arm, stroke typically affects one side more than the other, so we are reporting each armseparately
monitoring changes in isometric elbow flexion force using a dynamometer. A total of three trials will be taken on each side, with a rest break between trials. The average of the three trials will be recorded. Strength recorded in lbs, with a minimum value of zero. The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=20 Arms
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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Elbow Strength
Affected Arm
|
7.9 Change in Pounds
Standard Deviation 10.4
|
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Elbow Strength
Less Affected Arm
|
8.3 Change in Pounds
Standard Deviation 14.4
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SECONDARY outcome
Timeframe: Baseline, Day 6A neuropsychological measure that seeks to evaluate attention and inhibition. Subjects will be asked to read words or name ink colors as quickly as possible within a given time limit. The test supplies the examiner with three separate scores, including an ability to calculate an interference score. This final score allows for interpretation of cognitive flexibility, creativity and cognitive stress. This measure will be utilized to monitor subjects throughout their participation at specific time-points. Audio recording may be taken to ensure accurate recording of responses. The scale is from 1-18, with 10 being at expected level,. A score below 10 is worse performance than expected, and a score above 10 is greater than expected level. The score reported here is the change in score between Day 6 and baseline The values reported are differences from follow up (Day 6) and baseline calculated as: value at day 6 - value at baseline
Outcome measures
| Measure |
Hypoxia
n=10 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
|
|---|---|
|
D-KEFS Color-Word Interference Test
|
-0.1 Change in score on a scale
Standard Deviation 1.9
|
SECONDARY outcome
Timeframe: Baseline, day 6Quick short tests to assess clinical status performed by physician to ensure no change in neurologic status, The values reported are the count of participants who were found to have no change in neurolgical status from baseline to day 6 by the clinician
Outcome measures
| Measure |
Hypoxia
n=10 Participants
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
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5 Minute Neurological Test
|
10 Participants
|
Adverse Events
Hypoxia
Serious events: 0 serious events
Other events: 4 other events
Deaths: 0 deaths
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Hypoxia
n=16 participants at risk
During each session, study participants will receive a single sequence of AIH, consisting of 15 x 60-seconds periods of hypoxia alternating with 90-seconds of normoxia (21% O2), for a total of 30 minutes, whilst in a seated upright position. AIH will be applied by directing gas flow to a reservoir bag connected via plastic tubing to a non re-breathing facemask/respiratory valve system while the participants are in a seated position. Defined gas mixtures will be delivered by manual adjustment of one-way valves attached to a hypoxia generator.
Acute Intermittent Hypoxia (AIH): An oxygen monitor will continuously measure and record the fraction of inspired oxygen delivered to the subject. Inspired fraction of oxygen (FiO2) of the gas mixture will be individually adjusted using the valve settings to reach the targeted SpO2. The gas mixtures administered during the four sessions will be 21% O2 (target SpO2 = 95%), 17% O2 (target SpO2 = 92%), 13% O2 (target SpO2 = 87%) and 9% O2 (target SpO2 = 82%).
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|---|---|
|
Cardiac disorders
Baseline Elevated Blood pressure
|
6.2%
1/16 • Number of events 1 • Adverse events were collected over the duration of intervention as well as at the single follow up which was within 1 week of interventions */8all occurred at 1 week or less**
Adverse events were specifically questioned before intervention, during intervention, and following intervention for up to 2 hours following intervention initation. Participants were able to list any adverse event on top of the established events.
|
|
Cardiac disorders
Baseline Bradycardia
|
12.5%
2/16 • Number of events 2 • Adverse events were collected over the duration of intervention as well as at the single follow up which was within 1 week of interventions */8all occurred at 1 week or less**
Adverse events were specifically questioned before intervention, during intervention, and following intervention for up to 2 hours following intervention initation. Participants were able to list any adverse event on top of the established events.
|
|
General disorders
Claustrophobia
|
6.2%
1/16 • Number of events 1 • Adverse events were collected over the duration of intervention as well as at the single follow up which was within 1 week of interventions */8all occurred at 1 week or less**
Adverse events were specifically questioned before intervention, during intervention, and following intervention for up to 2 hours following intervention initation. Participants were able to list any adverse event on top of the established events.
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Additional Information
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place