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

Overview

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

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.

Interventions

• 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.
• 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.

Primary outcome measures

• Global cognitive function [Time frame: Baseline and 8 weeks (post-intervention)]
• Subjective cognitive function [Time frame: Baseline and 8 weeks (post-intervention)]
• Attention and executive function [Time frame: Baseline and 8 weeks (post-intervention)]
• Verbal memory [Time frame: Baseline and 8 weeks (post-intervention)]
• Reaction time [Time frame: Baseline and 8 weeks (post-intervention)]

Secondary outcome measures (12)

• Forced vital capacity [Time frame: Baseline and 8 weeks (post-intervention)]
• Forced expiratory volume in 1 second (FEV1) [Time frame: Baseline and 8 weeks (post-intervention)]
• FEV1/FVC [Time frame: Baseline and 8 weeks (post-intervention)]
• Peak expiratory flow [Time frame: Baseline and 8 weeks (post-intervention)]
• Forced expiratory flow at 25-75% of FVC [Time frame: Baseline and 8 weeks (post-intervention)]
• Maximal inspiratory pressure [Time frame: Baseline and 8 weeks (post-intervention)]
• Maximal expiratory pressure [Time frame: Baseline and 8 weeks (post-intervention)]
• Respiratory muscle endurance [Time frame: Baseline and 8 weeks (post-intervention)]
• Exercise capacity [Time frame: Baseline and 8 weeks (post-intervention)]
• Dyspnea [Time frame: Baseline and 8 weeks (post-intervention)]
• Fatigue [Time frame: Baseline and 8 weeks (post-intervention)]
• Fractional exhaled nitric oxide [Time frame: Baseline and 8 weeks (post-intervention)]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Istanbul University-Cerrahpaşa, Cardiology Institute — Istanbul

Identifiers

NCT: NCT07581587 · 952129

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗