American Heart Association- Stroke/Hypoxia Study

NCT ID: NCT04019522

Last Updated: 2024-01-18

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2019-07-15
• Study Completion Date: 2024-03-01

Brief Summary

Of the 795,000 people who experience a stroke every year in the US, only a small percentage will achieve full recovery. While current therapies promote strength and endurance, none directly address the unique potential of the brain to reorganize following injury. The goal of this project is to explore the effects of a novel therapy, acute intermittent hypoxia (AIH). During this therapy, individuals receive brief bouts of reduced oxygen levels by inhalation through a face mask. (This is akin to being on top of a tall mountain). In brief exposures, AIH is known to trigger the release of specific proteins that help the brain adapt to oxygen reductions. Published results in people with incomplete spinal cord injury have shown that AIH enhances muscle strength and coordination rather quickly. The research team aims to study the effects of AIH in stroke survivors.

Detailed Description

Stroke is the second leading cause of death and a leading cause of long-term disability worldwide. Despite the spontaneous recovery that occurs following a hemispheric stroke, more than half of stroke patients show substantial residual impairments, imposing a significant human and economic burden. This burden is likely to increase in coming decades, due to a rapidly aging population, and the associated progression of cardiovascular risk factors. Accordingly, new interventions to alleviate impairment in stroke survivors are urgently needed. The development and testing of one such novel intervention, termed Acute Intermittent Hypoxia (AIH), is the primary focus of this AHA Innovative Project Award.

The aim is to answer questions related to safety and preliminary efficacy of AIH in stroke survivors. First, the Investigators will establish whether brief reductions in inhaled oxygen concentration can be safely tolerated in stroke survivors. A clinician will closely monitor subjects for any adverse events.

The second aim is to establish the effects of AIH on elbow flexion/extension strength, and on hand grip and pinch strength. Subjects will be monitored closely for any adverse events during these experiments. Data will be analyzed to determine if there is an improvement in key outcomes at any dose level.

Conditions

Stroke

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

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.

Group Type: EXPERIMENTAL

Acute Intermittent Hypoxia (AIH)

Intervention Type: OTHER

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%).

Interventions

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%).

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

Age ≥18 years;

A first time, unilateral, ischemic, hemispheric stroke, confirmed by magnetic resonance imaging (MRI);

Chedoke assessment > 3

Ability to open and close affected hand

Able to understand and communicate in English

Be able to consent independently

≥ 6 months post stroke

Must have a hemoglobin level above 10g/dl (to be confirmed using handheld noninvasive lab equipment)

Must have ability to attend research visits with a companion for assistance

WOCBP must be comfortable confirming negative pregnancy prior to hypoxia experimental therapy.

Exclusion Criteria

Brain stem or cerebellar stroke; mean Fazekas score rated on initial fluid-attenuated inversion recovery MRI ≥3

Severe aphasia, preventing subject from understanding the protocol and giving written consent;

History of prior neurological disorder;

Pre-existing hypoxic pulmonary disease,

Severe hypertension (>160/100)

Ischemic cardiac disease.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Shirley Ryan AbilityLab

OTHER

Sponsor Role: lead

Responsible Party

Zev Rymer

Director Single Motor Unit Laboratory, Research Arms + Hands Lab

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Zev Rymer, MD/PhD

Role: PRINCIPAL_INVESTIGATOR

Principal Investigator

Locations

Shirley Ryan AbilityLab

Chicago, Illinois, United States

Countries

United States

References

Pearcey GEP, Barry AJ, Sandhu MS, Carroll TJ, Roth EJ, Rymer WZ. Acute Intermittent Hypoxia in People Living With Chronic Stroke: A Case Series. Stroke. 2025 Apr;56(4):1054-1057. doi: 10.1161/STROKEAHA.124.046620. Epub 2025 Feb 25.

Reference Type: DERIVED

PMID: 39996325 (View on PubMed)

Other Identifiers

STU: 00208610

Identifier Type: -

Identifier Source: org_study_id