Blood Flow Reserve: Effects After Training With Heavy Inspiratory Exercises

Not Applicable

Recruiting

• Conditions: Coronary Artery Disease
• Interventions: Device: Low-intensity IMST; Device: High-intensity IMST

• Registration Number: NCT05632614
• Lead Sponsor: Ottawa Heart Institute Research Corporation

Brief Summary

The goal of this single-site, parallel-group, double-blind, sham-controlled randomized control trial is to examine the effect of high-intensity inspiratory muscle strength training (IMST) on coronary blood flow assessed using positron emission tomography coronary perfusion imaging in patients with coronary artery disease (CAD).

The main question it aims to answer are:

• if high-intensity IMST will improve coronary blood flow in patients with CAD, which could be assessed using positron emission tomography coronary perfusion imaging.

Participants will be asked to complete the 8-week high-intensity or low-intensity IMST. Researchers will compare high and low-intensity IMST groups to see if coronary blood flow increases after IMST.

Detailed Description

Coronary artery disease (CAD) is a leading cause of morbidity and mortality. With the aging population, increasing number of patients with CAD has frailty and immobility. The health benefits of traditional aerobic exercise have been well-established; however, alternative exercise programs, such as inspiratory muscle training (IMST), may provide greater merits. IMST is a form of exercise that engages the diaphragm and accessory respiratory muscles to repeatedly inhale against resistance, which can be achieved in less time and widely applicable even for immobile or frail patients compared to conventional aerobic exercise. Since barriers to conventional exercise training include immobility, lack of time, and access to facilities, IMST may be a beneficial exercise form that can overcome those factors. A previous study has shown that high-intensity IMT can lower blood pressure and improved vascular endothelial function. Improvements in endothelial function of coronary arteries could improve coronary blood flow, leading to the improvement of anginal symptoms as well as quality of life. IMST might offer a widely applicable, feasible, time-efficient form of training for CAD patients. Our study will examine the preliminary efficacy of IMST on coronary blood flow in patients with CAD.

Study Timeline

• Study First Submitted: 2022-10-12
• Study First Submitted QC: 2022-11-21
• Study First Posted: 2022-11-30
• Study Start: 2023-05-08
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-08
• Last Update Posted: 2024-04-09
• Primary Completion: 2024-12-31
• Study Completion: 2025-06-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 40

Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Low-intensity IMST	Low-intensity IMST	Participants who will be trained with low-intensity IMST
High-intensity IMST	High-intensity IMST	Participants who will be trained with high-intensity IMST

Primary Outcome Measures

Name	Time	Method
Global myocardial flow reserve	Through study completion, an average of 8 weeks	Change in global myocardial flow reserve on positron emission tomography coronary perfusion imaging before and after IMST
Global stress myocardial blood flow	Through study completion, an average of 8 weeks	Change in global stress myocardial blood flow on positron emission tomography coronary perfusion imaging before and after IMST

Secondary Outcome Measures

Name	Time	Method
Mean segmental (17-segment model) myocardial flow reserve	Through study completion, an average of 8 weeks	Change in mean segmental (17-segment model) myocardial flow reserve on positron emission tomography coronary perfusion imaging before and after IMST
General quality of life	Through study completion, an average of 8 weeks	Change in general Quality of life assessed using the EQ5D-5L
Angina symptom	Through study completion, an average of 8 weeks	Change in angina symptom assessed using the Seattle angina Questionnaire
Respiratory Muscle Strength	Through study completion, an average of 8 weeks	Respiratory Muscle Strength assessed by % change in maximal inspiratory pressure
Global coronary vascular resistance at stress and rest	Through study completion, an average of 8 weeks	Change in global coronary vascular resistance at stress and rest on positron emission tomography coronary perfusion imaging before and after IMST
Maximum myocardial flow reserve	Through study completion, an average of 8 weeks	Change in maximum myocardial flow reserve on positron emission tomography coronary perfusion imaging before and after IMST
Maximum coronary vascular resistance at stress and rest	Through study completion, an average of 8 weeks	Change in maximum coronary vascular resistance at stress and rest on positron emission tomography coronary perfusion imaging before and after IMST
Mean segmental (17-segment model) myocardial blood flow at stress and rest	Through study completion, an average of 8 weeks	Change in mean segmental (17-segment model) myocardial blood flow at stress and rest on positron emission tomography coronary perfusion imaging before and after IMST
Summed stress score, summed rest score, and summed difference score	Through study completion, an average of 8 weeks	Change in summed stress score, summed rest score, and summed difference score on positron emission tomography coronary perfusion imaging before and after IMST
% left ventricular ischemia	Through study completion, an average of 8 weeks	Change in % left ventricular ischemia on positron emission tomography coronary perfusion imaging before and after IMST
Global rest myocardial blood flow	Through study completion, an average of 8 weeks	Change in global rest myocardial blood flow on positron emission tomography coronary perfusion imaging before and after IMST
Maximum myocardial blood flow at rest and stress	Through study completion, an average of 8 weeks	Change in maximum myocardial blood flow at rest and stress on positron emission tomography coronary perfusion imaging before and after IMST
Adherence of IMST program	Through study completion, an average of 8 weeks	The proportion of participants adhering to prescribed IMST sessions
Maximal segmental (17-segment model) myocardial blood flow at stress and rest	Through study completion, an average of 8 weeks	Change in maximal segmental (17-segment model) myocardial blood flow at stress and rest on positron emission tomography coronary perfusion imaging before and after IMST
Resting blood pressure	Through study completion, an average of 8 weeks	Resting blood pressure measured in a seated position after a 5-minute rest period using an automated blood pressure monitor.

Trial Locations

Locations (1)

University of Ottawa Heart Institute; 🇨🇦 Ottawa, Ontario, Canada