An interventional study of Intermittent hypoxic-hyperoxic training and Intermittent hypoxic-hyperoxic training/control in COVID-19, Chronic Heart Failure and Hypertension, sponsored by I.M. Sechenov First Moscow State Medical University. Completed at 1 site in Russia. Open to participants aged 40 Years to 75 Years. Per ClinicalTrials.gov, last updated 2025-07-11.
Sponsored by I.M. Sechenov First Moscow State Medical University · Not applicable, Interventional, and Supportive care
Aim of this prospective, interventional, single-center, randomized study is to evaluate the efficacy and safety of intermittent hypoxic-hyperoxic training (IHHT) as a rehabilitation method in patients with cardiovascular pathology in the early period after coronavirus infection.
The study will include 60 patients with cardiovascular pathology who underwent confirmed by laboratory tests COVID-19 infection 1-3 months ago with the degree of lung lesion CT3, CT4, who were admitted to the University Clinical Hospital No. 4 of I.M. Sechenov First Moscow State Medical University. The patients will be divided into 2 groups (intervention and control groups).
Intervention group will inhale hypoxic gas mixtures (10-12% O2) followed by exposure to a hyperoxic gas mixture with 30-35% O2 5 times a week for 3 weeks, while control group will undergo a simulated IHHT.
All the patients will undergo identical laboratory and instrumental testing before IHHT, after the last IHHT procedure, in a month after the last IHHT procedure and in 6 months.
Estimated result of the study is to confirm or refute the hypothesis of the study that a three-week course of IHHT in patients with cardiovascular pathology in the early period after coronavirus infection can improve exercise tolerance, as well as the quality of life and psychoemotional status, and affect the dynamics of laboratory and instrumental parameters.
Aim of this prospective, interventional, single-centered, randomized study is to evaluate the efficacy and safety of intermittent hypoxic-hyperoxic training as a rehabilitation method in patients with cardiovascular pathology in the early period after coronavirus infection.
The study will include 60 patients with cardiovascular pathology who underwent confirmed by laboratory tests COVID-19 infection (polymerase chain reaction (PCR) testing, enzyme-linked immunosorbent assay (positive result at least 1 time)) 1-3 months ago with the degree of lung lesion CT3, CT4, who were admitted to the University Clinical Hospital No. 4 of I.M. Sechenov First Moscow State Medical University.
Patients will be randomized via the random number table method into two groups, comparable by gender, age and comorbidity:
Intermittent hypoxic-hyperoxic training (intervention group) group, 30 patients who will receive 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks. Patients in the IHHT group will inhale hypoxic gas mixtures (10-12% O2) followed by exposure to a hyperoxic gas mixture with 30-35% O2.
A control group of 30 patients will undergo a simulated IHHT course with the same "exposure" time and number of sessions. Patients of this group will breathe normoxic gas mixture using the same equipment; ordinary humidified air is supplied through the mask during the entire session.
Patients eligible for inclusion will undergo the following investigations:
The statistical processing will be performed using the Python Software Foundation version 3.8 for Windows (Delaware, USA).
Estimated result of the study is to confirm or refute the hypothesis of the study that a three-week course of IHHT in patients with cardiovascular pathology in the early stages after suffering a coronavirus infection can improve exercise tolerance, as well as the quality of life and psychoemotional status, and affect the dynamics of laboratory and instrumental parameters.
7,990 studies on the registry are indexed under COVID-19; 466 are open to participants now.
This study's enrollment of 43 is below the median of 102 across 4,364 interventional studies indexed under COVID-19.
Browse COVID-19 studies →I.M. Sechenov First Moscow State Medical University is the lead sponsor of 137 studies on the registry; 28 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
One or more cardiovascular pathologies in the anamnesis:
Non-inclusion criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
NYHA class (heart failure)
The New York Heart Association’s four classes of how much heart failure limits physical activity.
Studies set their own limit — many outside heart failure leave out class III–IV, while heart failure studies may ask for a particular class. Check the class this study names.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The patients with cardiovascular pathology who underwent confirmed by laboratory tests COVID-19 infection 1-3 months ago with the degree of lung lesion CT3, CT4, who were admitted to the University Clinical Hospital No. 4 of I.M. Sechenov First Moscow State Medical University will be included in the study.
Procedure: Intermittent hypoxic-hyperoxic training
The patients with cardiovascular pathology who underwent confirmed by laboratory tests COVID-19 infection 1-3 months ago with the degree of lung lesion CT3, CT4, who were admitted to the University Clinical Hospital No. 4 of I.M. Sechenov First Moscow State Medical University will be included in the study.
Procedure: Intermittent hypoxic-hyperoxic training/control
IHHT will be carried out using the ReOxy normobaric hypoxic therapy apparatus (Bitmos GmbH, Germany, 26790/10221, 04/10/2019). Each patient will undergo a hypoxic test to assess the individual response to hypoxia. The minimum safe SpO2 value is 82%, and the maximum allowable heart rate increase during exercise is + 50% of the starting value. When these parameters are reached, an automatic switch to the supply of a hyperoxic gas mixture (35-40% oxygen) occurs till the SpO2 level is 100%. During each training session a hypoxic gas mixture is supplied to the patient in an intermittent mode, alternating with the supply of a hyperoxic gas mixture. On average, each workout includes 6 of the above cycles. The total time of inhalation of a hypoxic gas mixture during one procedure is 20-30 minutes.
IHHT will be carried out using the ReOxy normobaric hypoxic therapy apparatus (Bitmos GmbH, Germany, 26790/10221, 04/10/2019). A control group of 30 patients will undergo a simulated IHHT course (with the same "exposure" time and number of sessions as intervention group - 15 sessions, 40-minutes long each, 5 workouts per week for 3 weeks). Patients of this group will breathe normoxic gas mixture (ordinary humidified air is supplied through the mask) during the entire session.
Change in the levels of proinflammatory cytokines.
This outcome will be assessed by taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of proinflammatory cytokines such as Interleukin-1, Interleukin-6, Interleukin-18 and Tumor necrosis factor.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change of the endothelial function
This outcome will be assessed via taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of endothelin-1 and nitric oxide. Measurement of endothelial function will be done by using Flow Mediated Dilation (FMD). The technique involves ultrasound measurement of arterial dilation in response to a 5-minute occlusion of the brachial artery with a blood pressure cuff.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Changes in indicators of diastolic dysfunction.
This outcome will be assessed via transthoracic echocardiography (EchoCG). Transthoracic EchoCG will be performed to assess the heart structure and function: unidimensional (M-mode), two-dimensional (B-mode) and Doppler. Diastolic function of the left ventricle will be assessed using pulse-wave, constant-wave, and tissue Doppler studies. Received data will be compared to the initial one before the IHHT sessions started and the conclusion about diastolic dysfunction will be made.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in exercise tolerance after intermittent hypoxic-hyperoxic training.
Exercise tolerance will be determined via using a six-minute walk test . The six-minute walk test will measure the distance an individual is able to walk over a total of six minutes on a hard, flat surface.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in maximum level of oxygen consumption after intermittent hypoxic-hyperoxic training.
Exercise tolerance will be determined via using a spiroergometry to determine the patient's oxygen consumption. The spiroergometric test will be performed under continuous stepwise increasing load. The duration of each load step is 5 min; the initial load level is 25 W, followed by an increase in load at each step by the same amount. The results of the test will be used to evaluate the achievement of the maximum level of oxygen consumption (in l/min or ml/min/kg body weight). Received data will be compared to the initial one before the IHHT sessions started and the conclusion will be made.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in the levels of ferritin.
This outcome will be assessed by taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of long-term inflammatory markers such as ferritin.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in the levels of C-reactive protein.
This outcome will be assessed by taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of long-term inflammatory markers such as C-reactive protein.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in the levels of D-dimer.
This outcome will be assessed by taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of long-term inflammatory markers such as D-dimer.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Change in the levels of fibrinogen.
This outcome will be assessed by taking blood samples from a peripheral vein before and after IHHT to determine and compare the levels of long-term inflammatory markers such as fibrinogen.
Time frame: In 6 months after the reception of 15 IHHT sessions, 40-minutes long each (5 workouts per week) for 3 weeks.
Plan to share: No — No, as it is prohibited by Local Ethics Committee of I.M. Sechenov First Moscow State Medical University. Any necessary information may be provided after official request to Study Principal Investigator
No publications or documents are linked to this record.
Ran from Dec 2021 to primary completion in Dec 2023, 24 months.
Of 1,338 non-industry interventional studies with no phase under COVID-19, half reached primary completion within 9 months of starting (the median), counting those still running; a quarter within 3 and three quarters within 20. This study's 24 months is above that.
Counting every sponsor, half of 1,476 studies reached it within 9 months; a quarter within 3 and three quarters within 19.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Nov 2023. You cannot join it, but the record below documents what was studied.
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