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

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

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.

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