Investigation of the Effect of Inspiratory Muscle Training and Dual-Task Inspiratory Muscle Training on Cognitive Functions in Heart Failure

The goal of this clinical trial is to evaluate whether dual-task inspiratory muscle training (IMT) is effective in improving cognitive and functional outcomes in adults with heart failure. It will also assess the effects of standard IMT and compare both approaches.

The main questions it aims to answer are:

• Does dual-task IMT improve cognitive function more than standard IMT or no intervention?
• Does dual-task IMT improve respiratory function, inspiratory muscle strength, and exercise capacity?
• What are the effects of dual-task IMT on symptoms such as dyspnea and fatigue, and on quality of life, anxiety, and depression?

Dual-task IMT, standard IMT, and a control group (no additional intervention) will be compared to determine which approach is more effective in patients with heart failure (HF).

Participants will:

• Be randomly assigned to one of three groups: dual-task IMT, standard IMT, or control
• Perform IMT training 5 days per week for 8 weeks (2 sessions per day, 15 minutes each) if assigned to an intervention group
• Complete 1 supervised in-person session per week and 4 sessions via telerehabilitation if assigned to an intervention group
• Undergo assessments before and after the 8-week intervention, including cognitive tests, respiratory function, exercise capacity, and symptom evaluations

Study Overview

• Status: Not yet recruiting
• Conditions: Heart Failure
• Intervention / Treatment: Behavioral: Dual-Task IMT; Behavioral: IMT

Detailed Description

HF is a complex clinical syndrome associated with reduced functional capacity and a high prevalence of cognitive impairment, which negatively affects prognosis and quality of life. Inspiratory muscle weakness is also common in HF and is associated with increased dyspnea and reduced exercise tolerance. The IMT has been shown to improve respiratory and functional outcomes; however, its effects on cognitive function remain unclear. Dual-task approaches, involving the simultaneous performance of motor and cognitive tasks, have been suggested to enhance neurocognitive integration and improve both cognitive and functional performance. Despite this, the effects of IMT applied within a motor-cognitive dual-task framework in HF patients have not been sufficiently investigated. This study is designed as a prospective, randomized controlled, single-blind trial. A total of 54 patients with heart failure will be included and randomly assigned to three groups: control, standard IMT, and dual-task IMT. Both intervention groups will receive IMT at 50% of maximal inspiratory pressure (MIP) for 8 weeks, 5 days per week, 2 sessions per day (15 minutes each). One session per week will be supervised, and the remaining sessions will be conducted via telerehabilitation (4 days/week, 2 sessions per day). Training intensity will be adjusted weekly. In the dual-task IMT group, cognitive tasks targeting attention, memory, and executive functions will be performed simultaneously with IMT. Assessments will be performed before and after the intervention. Primary outcomes will include cognitive function, while secondary outcomes will include respiratory function, inspiratory muscle strength and endurance, exercise capacity, dyspnea, fatigue, nitric oxide levels, frailty, physical performance, quality of life, and psychological status. This study aims to determine the effectiveness of dual-task IMT compared to standard IMT and control conditions, and to provide evidence for integrated rehabilitation approaches in patients with HF.

• Study Type: Interventional
• Enrollment (Estimated): 54
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Vildan Fidanoglu, PT, MSc; Phone Number: 1281 212-924-24-44; Email: fzt.vildanbayraktaroglu@hotmail.com

Study Locations

• Turkey (Türkiye)
  • Fatih
    • Istanbul, Fatih, Turkey (Türkiye), 34098
      • Istanbul University-Cerrahpasa, Cardiology Institute
      • Contact: Rengin Demir, Prof. Dr.; Phone Number: 212-459-20-00; Email: rengin.demir@iuc.edu.tr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 40 years
• Diagnosed with HF with reduced ejection fraction (HFrEF) according to the 2023 ESC HF Guidelines
• Classified as NYHA functional class I-III
• Clinically stable for at least 3 months and receiving stable pharmacological treatment
• Able to read and understand Turkish
• MoCA score ≥ 21
• Willingness to participate and provide written informed consent

Exclusion Criteria:

• Diagnosis of any neurological or neurodegenerative disease (e.g., Parkinson's disease, stroke, dementia, Alzheimer's disease)
• Diagnosis of pulmonary disease (e.g., chronic obstructive pulmonary disease, obstructive sleep apnea)
• Myocardial infarction within the last 6 months
• Uncontrolled hypertension and/or diabetes mellitus
• Severe valvular heart disease and/or uncontrolled arrhythmias
• Orthopedic, visual, or hearing impairments that may prevent independent test completion
• Inability to comply with study procedures or follow instructions

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dual-Task IMT; Participants will receive IMT combined with simultaneous cognitive tasks for 8 weeks (5 days/week, 2 sessions/day). One session per week will be supervised, and the remaining sessions will be performed via telerehabilitation. Training intensity will be set at 50% of MIP and adjusted weekly.	Behavioral: Dual-Task IMT; IMT will be applied using a threshold loading device at 50% of MIP for 8 weeks (5 days/week, 2 sessions/day, 15 minutes each). One session per week will be supervised, and the remaining sessions will be performed via telerehabilitation. During IMT, participants will simultaneously perform cognitive tasks targeting attention, memory, and executive functions, which will be varied weekly to minimize learning effects.; Other Names: Cognitive-Motor IMT; Cognitive-Motor Dual-Task; Dual-Task
Experimental: Standard IMT; Participants will receive IMT alone for 8 weeks (5 days/week, 2 sessions/day). One session per week will be supervised, and the remaining sessions will be performed via telerehabilitation. Training intensity will be set at 50% of MIP and adjusted weekly.	Behavioral: IMT; IMT will be applied using a threshold loading device at 50% of MIP for 8 weeks (5 days/week, 2 sessions/day, 15 minutes each). One session per week will be supervised, and the remaining sessions will be performed via telerehabilitation. No additional cognitive task will be applied during training.; Other Names: Inspiratory Muscle Training
No Intervention: Control (Usual Care); Participants will not receive any additional intervention and will continue their usual medical care. Assessments will be performed at baseline and after 8 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global cognitive function	Global cognitive function will be assessed using the Montreal Cognitive Assessment (MoCA), 0-30 point screening tool evaluating multiple cognitive domains including attention, memory, executive functions, visuospatial abilities, and language. Higher scores indicate better cognitive performance. The assessment will be administered by a certified physiotherapist.	Baseline and 8 weeks (post-intervention)
Subjective cognitive function	Subjective cognitive function will be assessed using the Cognitive Failures Questionnaire (CFQ), which evaluates perceived cognitive performance over the past 6 months. The questionnaire consists of 25 items rated on a 5-point Likert scale (0-4), with total scores ranging from 0 to 100. Higher scores indicate greater perceived cognitive impairment.	Baseline and 8 weeks (post-intervention)
Attention and executive function	Attention and executive function will be assessed using a Stroop Test (The Scientific and Technological Research Council of Türkiye, Basic Sciences Research Group version), a standardized tool evaluating selective attention, cognitive flexibility, and psychomotor speed. The test consists of five sections, and completion time, as well as the number of correct and incorrect responses, will be recorded for each section. Longer completion times and higher error rates indicate poorer performance.	Baseline and 8 weeks (post-intervention)
Verbal memory	Verbal memory will be assessed using the Öktem Verbal Memory Processes Test, which evaluates different components of verbal memory including learning, delayed recall, and recognition. The test involves repeated presentation of a target word list, followed by delayed recall and recognition tasks. Performance will be quantified using learning, spontaneous recall, and recognition scores. The learning score reflects total words recalled across repeated trials (maximum 15). Spontaneous recall is assessed approximately 40 minutes after the learning phase, during which participants are asked to recall the words without cueing. Recognition performance is based on identifying previously presented words among distractors. Higher scores indicate better verbal memory performance.	Baseline and 8 weeks (post-intervention)
Reaction time	Reaction time will be assessed using a BlazePod reaction kits. Participants, seated in front of a table, will respond to randomly illuminated light stimuli by tapping the lights as quickly as possible for 30 seconds using one hand. The system consists of four reaction pods positioned in a straight line at 20 cm intervals. Outcome measures will include total number of hits, total reaction time, and mean reaction time per stimulus. Missed responses will be recorded when the light deactivates before being tapped within 4 seconds. Lower reaction time indicates better performance.	Baseline and 8 weeks (post-intervention)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Forced vital capacity	Forced vital capacity (FVC) will be assessed using spirometry according to American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. It will be recorded from three acceptable maneuvers performed in a seated position, and the highest value will be used for analysis.	Baseline and 8 weeks (post-intervention)
Forced expiratory volume in 1 second (FEV1)	Forced expiratory volume in 1 second (FEV1) will be assessed using spirometry according to ATS/ERS guidelines. It will be recorded from three acceptable maneuvers performed in a seated position, and the highest value will be used for analysis.	Baseline and 8 weeks (post-intervention)
FEV1/FVC	FEV1/FVC ratio will be assessed using spirometry according to ATS/ERS guidelines. It will be recorded from three acceptable maneuvers performed in a seated position, and the highest value will be used for analysis.	Baseline and 8 weeks (post-intervention)
Peak expiratory flow	Peak expiratory flow (PEF) will be assessed using spirometry according to ATS/ERS guidelines. It will be recorded from three acceptable maneuvers performed in a seated position, and the highest value will be used for analysis.	Baseline and 8 weeks (post-intervention)
Forced expiratory flow at 25-75% of FVC	Forced expiratory flow at 25-75% of FVC (FEF25-75) will be assessed using spirometry according to ATS/ERS guidelines. It will be recorded from three acceptable maneuvers performed in a seated position, and the highest value will be used for analysis.	Baseline and 8 weeks (post-intervention)
Maximal inspiratory pressure	Maximal inspiratory pressure (MIP) will be assessed using a portable electronic mouth pressure device (MicroRPM; Micro Medical, UK), according to ATS/ERS guidelines. It will be measured in the seated position using a mouthpiece with nasal occlusion. Participants will perform maximal inspiratory effort for at least 2 seconds against an occluded airway. The highest value from three acceptable maneuvers with <10% variability will be recorded in cmH₂O and as a percentage of predicted values using Black and Hyatt reference equations. Higher values indicate better inspiratory muscle strength.	Baseline and 8 weeks (post-intervention)
Maximal expiratory pressure	Maximal expiratory pressure (MEP) will be assessed using a portable electronic mouth pressure device (MicroRPM; Micro Medical, UK), according to ATS/ERS guidelines. It will be measured in the seated position using a mouthpiece with nasal occlusion. Participants will perform maximal expiratory effort for at least 2 seconds against an occluded airway. The highest value from three acceptable maneuvers with <10% variability will be recorded in cmH₂O and as a percentage of predicted values using Black and Hyatt reference equations. Higher values indicate better expiratory muscle strength.	Baseline and 8 weeks (post-intervention)
Respiratory muscle endurance	Respiratory muscle endurance will be assessed using a constant-load threshold loading test with a pressure threshold device (POWERbreathe Classic Light Resistance, POWERbreathe International Ltd., UK). The test will be performed at 60% of MIP. Participants will breathe through the device for up to 10 minutes, and endurance will be recorded as the time sustained (seconds) and achieved pressure load (cmH₂O). Higher endurance time indicates better respiratory muscle endurance.	Baseline and 8 weeks (post-intervention)
Exercise capacity	Exercise capacity will be assessed using the 6-minute walk test (6MWT) according to ATS guidelines. Participants will be instructed to walk as far as possible for 6 minutes along a 30-meter corridor at a self-paced speed. A standardized rest period will be provided prior to testing. Total walking distance will be recorded in meters. Higher walking distance indicates better exercise capacity.	Baseline and 8 weeks (post-intervention)
Dyspnea	Dyspnea will be assessed using the Modified Medical Research Council (mMRC) Dyspnea Scale, a 0-4 point scale based on the level of physical activity that induces breathlessness. Higher scores indicate greater severity of dyspnea.	Baseline and 8 weeks (post-intervention)
Fatigue	Fatigue will be assessed using the Fatigue Severity Scale (FSS), a 9-item scale evaluating fatigue severity over the past week. Each item is rated on a 7-point Likert scale (1-7), and the total score is calculated by averaging item scores. A score ≥4 indicates severe fatigue. Higher scores indicate greater fatigue severity.	Baseline and 8 weeks (post-intervention)
Fractional exhaled nitric oxide	Fractional exhaled nitric oxide (FeNO) will be measured using a NObreath® device (Bedfont Scientific Ltd., UK) according to the ATS guidelines. Measurements will be performed with controlled expiratory flow, and mean values will be recorded. Participants will perform controlled exhalation at a constant flow rate (50 mL/s) following standardized pre-test conditions. The mean of two acceptable measurements will be recorded as FeNO (parts per billion, ppb).	Baseline and 8 weeks (post-intervention)
Frailty	Frailty will be assessed using the Edmonton Frail Scale, a 17-point scale evaluating multiple domains including cognition, general health status, functional independence, and social support. Scores range from 0 to 17, with higher scores indicating greater frailty severity.	Baseline and 8 weeks (post-intervention)
Physical performance	Physical performance will be assessed using the Short Physical Performance Battery (SPPB), including balance tests, 4-meter gait speed, and chair stand tests. Total scores range from 0 to 12, with higher scores indicating better performance.	Baseline and 8 weeks (post-intervention)
Quality of life (QoL)	Quality of life will be assessed using the Minnesota Living with Heart Failure Questionnaire, a 21-item disease-specific scale evaluating the physical and emotional impact of the disease over the past 4 weeks. Each item is scored from 0 to 5, with total scores ranging from 0 to 105. Higher scores indicate worse quality of life.	Baseline and 8 weeks (post-intervention)
Anxiety and depression	Anxiety and depression will be evaluated using the Hospital Anxiety and Depression Scale (HADS), a 14-item questionnaire with two subscales assessing anxiety and depression. Each subscale ranges from 0 to 21, with higher scores indicating greater symptom severity.	Baseline and 8 weeks (post-intervention)

Collaborators and Investigators

• Sponsor: Istanbul University - Cerrahpasa
• Investigators: Study Director: Rengin Demir, Prof. Dr., Istanbul University - Cerrahpasa

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: May 6, 2026
• First Posted (Actual): May 12, 2026

Study Record Updates

• Last Update Posted (Actual): May 12, 2026
• Last Update Submitted That Met QC Criteria: May 6, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Inspiratory muscle training; Dual-task; IMT
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Heart Diseases; Heart Failure
• Other Study ID Numbers: 952129

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No