This clinical trial will evaluate a two-week eccentric exercise program conducted as part of comprehensive cardiac rehabilitation in patients after a heart attack (myocardial infarction). Eccentric exercise involves muscle contractions while the muscles are lengthening and may allow the muscles to work at a relatively high load with a lower cardiovascular and metabolic demand than traditional exercise. The main aim of the study is to determine whether eccentric exercise affects blood levels of proteins released or regulated in response to physical activity, including musclin, interleukin-6, and myostatin. The study will also evaluate whether the program improves physical performance and functional capacity. Participants will complete eccentric cycling exercise on a semi-recumbent cycle ergometer during a two-week cardiac rehabilitation program. Blood samples and physical-function measurements will be collected before and after the intervention.
Exercise-based cardiac rehabilitation is an important component of secondary prevention after myocardial infarction. However, some patients experience reduced exercise tolerance or fear of physical activity, which may limit participation in rehabilitation and contribute to physical deconditioning, loss of muscle mass, and reduced functional capacity. Eccentric exercise is characterized by muscle contractions performed while the muscle is lengthening. Compared with traditional concentric exercise, eccentric exercise can provide a relatively high mechanical load to skeletal muscles while requiring lower oxygen consumption and imposing a lower metabolic demand. For this reason, eccentric training may be a useful rehabilitation strategy for patients who have limited exercise tolerance after myocardial infarction. The intervention will consist of a two-week eccentric cycling program performed on a semi-recumbent cycle ergometer as part of comprehensive cardiac rehabilitation. The training is intended to provide controlled loading of the lower-limb muscles while limiting excessive cardiovascular strain. The primary scientific objective is to evaluate changes in the molecular response to eccentric exercise, with particular emphasis on circulating myokines and exerkines. Blood concentrations of musclin, interleukin-6, and myostatin will be assessed before and after the rehabilitation period. The study will also evaluate changes in physical performance, muscle function, and functional exercise capacity using the assessments specified in the study protocol. The findings may help determine whether eccentric exercise produces beneficial molecular and functional adaptations in patients undergoing cardiac rehabilitation after myocardial infarction.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
60
Standard stage I inpatient cardiac rehabilitation provided after myocardial infarction and individualized according to each participant's clinical condition and exercise capacity. The program includes standard kinesitherapy and exercise-based rehabilitation procedures.
Supervised eccentric cycling exercise performed on a motor-driven semi-recumbent cycle ergometer in addition to standard inpatient cardiac rehabilitation. Sessions will last 10 to 30 minutes, with progressive adaptation during the first five sessions. Exercise workload will be individualized according to baseline exercise capacity. Perceived exertion and muscle soreness will be monitored during each session.
Florian Ceynowa Specialist Hospital in Wejherowo
Wejherowo, Pomeranian Voivodeship, Poland
Change From Baseline in Serum Musclin Concentration
Serum musclin concentration will be measured in fasting venous blood samples using an enzyme-linked immunosorbent assay (ELISA). The outcome will be calculated as the concentration measured after the intervention minus the baseline concentration and reported in ng/mL.
Time frame: Baseline and after completion of the 2-week inpatient cardiac rehabilitation program
Change From Baseline in Serum Myostatin Concentration
Serum myostatin concentration will be measured in fasting venous blood samples using an enzyme-linked immunosorbent assay (ELISA). The outcome will be calculated as the concentration measured after the intervention minus the baseline concentration.
Time frame: Baseline and after completion of the 2-week inpatient cardiac rehabilitation program
Change From Baseline in Serum Interleukin-6 Concentration
Serum interleukin-6 concentration will be measured in fasting venous blood samples using an enzyme-linked immunosorbent assay (ELISA). The outcome will be calculated as the concentration measured after the intervention minus the baseline concentration.
Time frame: Baseline and after completion of the 2-week inpatient cardiac rehabilitation program
Change From Baseline in Six-Minute Walk Distance
Functional exercise capacity will be assessed using the Six-Minute Walk Test. Participants will be instructed to walk as far as possible during 6 minutes along a designated walking course under the supervision of qualified medical personnel. The total distance covered will be recorded in meters. The outcome will be calculated as the post-intervention distance minus the baseline distance, with a positive value indicating an improvement in functional exercise capacity.
Time frame: Baseline, before initiation of the inpatient cardiac rehabilitation program, and after completion of the 2-week intervention
30-Second Chair-Stand Test
Functional lower-limb strength will be assessed using the 30-Second Chair-Stand Test. Participants will be instructed to repeatedly rise to a full standing position and return to a seated position during a 30-second period. The number of correctly completed repetitions will be recorded. The outcome will be calculated as the post-intervention number of repetitions minus the baseline number, with a positive value indicating an improvement in functional lower-limb performance.
Time frame: Baseline, before initiation of the inpatient cardiac rehabilitation program, and after completion of the 2-week intervention
Change From Baseline in Kinesiophobia Assessed Using the Tampa Scale for Kinesiophobia Heart
Fear of physical activity and movement related to the participant's cardiac condition will be assessed using the validated Polish version of the 17-item Tampa Scale for Kinesiophobia Heart. Participants will complete the questionnaire according to the standardized scoring procedure. The total score will be reported in points. The outcome will be calculated as the post-intervention total score minus the baseline total score. A negative change will indicate a reduction in kinesiophobia, whereas a positive change will indicate an increase in kinesiophobia.
Time frame: Baseline, before initiation of the inpatient cardiac rehabilitation program, and after completion of the 2-week intervention
Change From Baseline in Peak Force During the Isometric Mid-Thigh Pull Test
Maximal isometric lower-limb strength will be assessed using the Isometric Mid-Thigh Pull test performed on a force platform. Participants will perform a maximal isometric pull against a fixed bar while standing with partial flexion of the knee and hip joints. Peak force will be determined from the recorded ground reaction force signal and reported in newtons. The outcome will be calculated as the post-intervention peak force minus the baseline peak force, with a positive value indicating an increase in maximal isometric strength.
Time frame: Baseline, before initiation of the inpatient cardiac rehabilitation program, and after completion of the 2-week intervention
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