Neuromuscular Fatigability in Individuals With Heart Failure
NCT Number: NCT06551012
Status: NOT_YET_RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Heart Failure With Reduced Ejection Fraction
Interventions: DIETARY_SUPPLEMENT: Nitrate-rich beetroot juice|DIETARY_SUPPLEMENT: Beetroot juice with nitrate extracted
Sponsor: Newcastle University
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 28
Study Design: Allocation: RANDOMIZED|Intervention Model: CROSSOVER|Masking: DOUBLE (PARTICIPANT, INVESTIGATOR)|Primary Purpose: BASIC_SCIENCE
Start Date: 2025-01-01
Completion Date: 2027-04-01

Summary:
Brief summary

The aims of this project are to 1) characterise muscle fatigue in individuals with chronic heart failure during exercise involving a smaller and larger muscle mass (Part I), 2) to determine the effect of nitrate supplementation on muscle fatigue during large muscle mass exercise in individuals with chronic heart failure (Part II), 3) understand the impact of exercise intolerance on quality of life in individuals with chronic heart failure (Part III). The main questions it aims to answer are:

* Is muscle fatigue attenuated during exercise engaging a smaller vs larger muscle mass in individuals with chronic heart failure owing to lower central cardiopulmonary constraints?
* Can supplementation with nitrate-rich beetroot juice reduce muscle fatigue and/or accelerate post-exercise recovery of muscle function in response to whole body exercise in individuals with heart failure?
* What impact does exercise intolerance have on the lives of individuals with chronic heart failure?

For Part I, researchers will compare muscle fatigue during single- and double-leg incremental cycling in individuals with chronic heart failure.

For Part II, researchers will compare muscle fatigue in individuals with chronic heart failure during double-leg incremental cycling following a period of beetroot juice supplementation containing nitrate, or with a placebo drink consisting of beetroot juice with nitrate extracted.

For Part III, semi-structured interviews will be conducted to investigate the symptoms associated with performing physical activity and on the impact of exercise intolerance on quality of life in individuals with chronic heart failure.

Primary Outcome Measures: Maximal voluntary contraction force, Maximal voluntary contraction (MVC) force of the right knee extensor will be taken pre, during and post-exercise., 3 years
Secondary Outcome Measures: Voluntary activation, Voluntary activation (%) will be measured using supramaximal femoral nerve stimulation during maximal voluntary contractions at pre, during and post-exercise., 3 years|Resting evoked twitch force, Resting evoked twitch force (Newtons) will be measured using supramaximal femoral nerve stimulation following maximal voluntary contractions at pre, during and post-exercise., 3 years|Electromyography, Electromyography (root mean squared) of vastus lateralis measured throughout exercise, 3 years|Time constant for recovery of muscle oxygen uptake, Non-invasive measure of skeletal muscle oxidative capacity measured using NIRS-derived time constant for recovery of muscle oxygen uptake, 3 years|Microvascular responsiveness, A 5 minute period of occlusion will be used, followed by deocclusion. Using NIRS, the slope of the increase in oxygenated haemoglobin following deocclusion by will quantified through the upslope of a 10 s window following cuff release., 3 years|Cardiac output, Cardiac output (L/min) will be assessed throughout exercise using Bioreactance technology, 3 years|Stroke volume, Stroke volume (ml/min) will be assessed throughout exercise using Bioreactance technology, 3 years|Heart rate, Heart rate (bpm) will be assessed throughout exercise using Bioreactance technology, 3 years|Mean arterial blood pressure, Mean arterial blood pressure (mmHg) will be assessed throughout exercise using Bioreactance technology, 3 years|Oxygen consumption, Oxygen consumption (ml/kg/min) will be measured throughout exercise using a metabolic analyser, 3 years|Carbon dioxide production, Carbon dioxide production (ml/min) will be measured throughout exercise using a metabolic analyser throughout exercise, 3 years|Ventilation, Ventilation (L/min) will be measured throughout exercise using a metabolic analyser throughout exercise, 3 years|Carbon dioxide ventilatory equivalent, Litres of ventilation per litre of carbon dioxide production (Ve/VCO2) will be measured throughout exercise using a metabolic analyser throughout exercise, 3 years|Tissue oxygen saturation, Measurements of tissue oxygen saturation (%) taken from near-infrared spectroscopy throughout exercise, 3 years|Deoxygenated haemoglobin, Measurements of deoxygenated haemoglobin (%) will be taken from near-infrared spectroscopy throughout exercise, 3 years