None listed
Conditions
Brief summary
Background: Skeletal muscle alterations significantly contribute to exercise intolerance in heart failure (HF). Small muscle mass training, localised to the quadriceps femoris muscle group, has been proposed as an intervention to target these HF-related changes. The application of this training paradigm in HF is supported by a recent literature review that found improvements in whole-body exercise capacity, quadriceps muscle strength and health-related quality of life (QoL) in those with reduced ejection fraction. Since this training involves only one muscle group, it places a lower demand on the central circulation than whole-body exercise, thereby permitting a near-maximal intensity protocol. Hence, this proposed study will evaluate high-intensity small muscle mass training (HISMT) isolated to the knee extensor muscles in a conventional clinical context, with the aim to determine the additive effects of integrating HISMT within a standard HF rehabilitation program. Methods: This randomised, controlled, single-blind trial will aim to recruit 70 clinically stable participants aged 18 years and over with a HF diagnosis and New York Heart Association class I to III. Participants will be randomly allocated to either: (i) standard training (ST) alone: combination of upper and lower extremity cardiovascular and resistance-based exercises; or (ii) HISMT plus modified ST: bilateral, isolated knee extensor HISMT in addition to a modified version of the ST, so that the total volume of work will be similar to ST alone. The training interventions will be conducted twice weekly for 12 weeks in an outpatient setting. Outcome measurements will be performed at baseline and following the 12-week intervention period. The primary outcome measure will be exercise capacity (six-minute walk test), with secondary measures being physical performance (timed up and go test and 30-second sit-to-stand test), muscle strength (quadriceps maximal voluntary isometric contraction, knee extensor five-repetition maximum and hand grip strength), and health-related QoL (Kansas City Cardiomyopathy Questionnaire). Discussion: This study will assess whether there are greater improvements with incorporating knee extensor HISMT within a traditional HF rehabilitation program. It is hypothesised that the addition of HISMT will confer superior outcomes. In addition to extending current knowledge relating to small muscle mass training, the study will provide a unique perspective on the effects of HISMT within routine clinical practice, thus enabling the optimisation of exercise prescription for the HF patient population.
Interventions
High-intensity small muscle mass training (HISMT) plus modified standard training (MST): Participants will undertake isolated knee extensor HISMT during twice weekly exercise sessions, with the training load increased as tolerated over the 12-week training period. The HISMT protocol will consist of a series of bilateral, dynamic knee extension exercises against a resistive load using a knee extensor machine. This training will be undertaken as 3 sets of up 25 repetitions, with a concentric-eccen
High-intensity small muscle mass training (HISMT) plus modified standard training (MST): Participants will undertake isolated knee extensor HISMT during twice weekly exercise sessions, with the training load increased as tolerated over the 12-week training period. The HISMT protocol will consist of a series of bilateral, dynamic knee extension exercises against a resistive load using a knee extensor machine. This training will be undertaken as 3 sets of up 25 repetitions, with a concentric-eccentric contraction time ratio of 1:2. During each session, participants will also undertake a modified version of the standard training (ST; described in comparator/control treatment section below) so that the total volume of work is similar to those undertaking ST alone. The perceived levels of exertion (using the Borg 0-10 category ratio (CR) scale), quadriceps muscle fatigue (using the Borg 0-10 CR scale) and knee pain (using a 0-10 integer numerical rating scale; 0 – no pain, 10 – worst pain imaginable) will be ascertained prior to commencing the HISMT protocol and following completion of each set. The aim of the HISMT protocol is to achieve temporary muscle failure at the end of each set (determined by quadriceps muscle fatigue rating of at least 7 on the Borg 0-10 CR scale), without eliciting any adverse signs or symptoms or musculoskeletal pain. The exercise training will be administered by a physiotherapy clinician with a minimum of 10 years experience and undertaken within a face-to-face, group-based outpatient HF rehabilitation program at two sites i.e. Gold Coast Hospital and Health Service (GCHHS) and The Prince Charles Hospital (TPCH). Each training session has capacity for up to 12 patients and is approximately 90 minutes in duration. Adherence to the allocated intervention will be monitored by means of session attendance and completion of the prescribed exercise program.
Sponsors
Menaka Louis
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
A diagnosis of heart failure (HF) as per the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand HF guidelines (2018); Clinically stable and deemed suitable to participate in an exercise program; New York Heart Association (NYHA) class I to III; Aged 18 years and over.
Exclusion criteria
Comorbid disease, or physical, cognitive or behavioural factors that interfere with or prevent participation in exercise training; Contraindications to exercise testing or training as per the HF Association/European Association for Cardiovascular Prevention and Rehabilitation position paper (2011).
Outcome results
None listed