NCT07688863Enrolling by invitation
Comparative Effects of Different Inspiratory Muscle Training Modalities in Patients With Heart Failure.
Effects of Inspiratory Muscle Training on Maximal Inspiratory Pressure, Cardiopulmonary Capacity, and Quality of Life in Patients With Heart Failure
Source: ClinicalTrials.gov · Last updated 7 Jul 2026
Brief summary (registry, in English)
The purpose of this study is to compare the effects of three different modalities of inspiratory muscle training (IMT) in patients diagnosed with chronic heart failure who exhibit reduced or mid-range left ventricular ejection fraction (LVEF \< 50%). Patients will be recruited from cardiac rehabilitation programs and must be clinically stable before entering the protocol. The study has a total duration of 8 weeks and is divided into two distinct phases. During the first 2 weeks, participants will undergo a familiarization phase to learn the proper breathing techniques with the devices and to complete baseline resting and functional clinical evaluations. The following 6 weeks will comprise the effective training phase, consisting of 3 weekly sessions of high-intensity inspiratory training. Participants will be randomly assigned to one of three parallel groups: * Group 1 (Pressure-Threshold IMT): Participants will train using a mechanical pressure-threshold device at an initial high-intensity load of 60% of their baseline maximal inspiratory pressure (MIP). * Group 2 (Electronic Flow-Resistive IMT): Participants will train at a high-intensity load of 60% of their baseline MIP utilizing the PowerBreathe KH2 electronic device, which provides a dynamic, flow-dependent automated resistance. * Group 3 (Control / Sham IMT): Participants will perform the same breathing protocol but using a mechanical device set at a low, non-training intensity of 15% of their baseline MIP. For all three groups, training volume is standardized to 5 sets of 8 repetitions (40 inspiratory efforts per session). To ensure progressive overload, training intensity will be increased by 10% of the initial baseline MIP value every 2 weeks. The main outcomes to be evaluated before and immediately after the 8-week period include maximal inspiratory muscle strength, structural changes in respiratory muscles (diaphragmatic and parasternal intercostal thickening fraction measured via ultrasound), cardiac autonomic balance (heart rate variability), and health-related quality of life. Additionally, dynamic responses such as respiratory and locomotor muscle oxygenation (measured continuously via Near-Infrared Spectroscopy \[NIRS\] during a respiratory metabolic reflex provocation test) and overall cardiopulmonary exercise capacity (measured via an incremental cycle ergometer test) will be analyzed. This study aims to determine which training modality provides the most effective physiological adaptations to optimize rehabilitation in this population.
- Status (registry)
- Enrolling by invitation
- Study type
- Interventional
- Enrollment
- 60 (estimated)
- First submitted
- 24 Jun 2026
- Start date
- 17 Jun 2026
- Primary completion date
- Sept 2026
- Lead sponsor
- Universidad Nacional Andres Bello
- Diseases
- Heart failure
- NCT number
- NCT07688863
What you commit to
- Study type: Interventional
- Planned participants: 60
- From 17 Jun 2026 to the primary completion date, Sept 2026
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Other illness
- Presence of primary severe pulmonary or respiratory diseases (e.g., Chronic Obstructive Pulmonary Disease \[COPD\] GOLD stage III or IV, active asthma, severe pulmonary hypertension, or restrictive lung disease).
- Recent myocardial infarction, unstable angina, or coronary artery bypass graft (CABG) surgery within the last 6 months.
- Severe uncorrected valvular heart disease or complex, uncontrolled ventricular arrhythmias.
- Cognitive impairment or psychological conditions that limit the ability to follow instructions, maintain correct diaphragmatic breathing technique, or properly seal the training device mouthpiece.
- Any acute infectious, inflammatory, or medical condition that, in the investigator's opinion, poses a safety risk during high-intensity training.
Other
- Orthopedic, neurological, or musculoskeletal limitations that prevent the safe execution of an incremental cardiopulmonary exercise test on a cycle ergometer or the performance of the isometric handgrip protocol.
- Current participation in another structured physical rehabilitation or formal sports training program that could confound the systemic results of the intervention.
Who the study is looking for
- Documented clinical diagnosis of chronic Heart Failure with Reduced Ejection Fraction (HFrEF) according to the European Society of Cardiology (ESC) guidelines.
- Left Ventricular Ejection Fraction (LVEF) less than or equal to 40% documented by echocardiography within the last 12 months.
- Clinically stable condition for at least 3 months prior to enrollment, with no hospitalizations or major changes in optimized medical therapy.
- New York Heart Association (NYHA) functional class I to IV.
- Evidence of inspiratory muscle weakness, defined as a baseline Maximal Inspiratory Pressure (MIP) \< 70% of the predicted value for age and sex.
- Age greater than or equal to 18 years.
- Patient must be capable of understanding the protocol instructions and must provide signed written informed consent.
Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Universidad Andrés Bello, Campus Viña del Mar Coordinator of this site? Confirm its status | Viña del Mar | Chile | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.