BACKGROUND:
Congestive heart failure (CHF) is increasingly prevalent worldwide and is associated with
significant morbidity and mortality. Poor exercise capacity is well known as a risk factor
for poor prognosis. The deconditioning is mainly associated with a decrease in leg muscle
mass and loss of leg strength as well as loss of muscle endurance. This affects especially
elderly patients. To improve this condition in CHF electrical muscle stimulation (EMS) is a
suitable method of training, which hardly affects the heart. However, most EMS existing
stimulation protocols are uncomfortable and not user-friendly, especially for elderly
patients. The Russian space medicine has many years' experience in specific EMS stimulation
protocols, which are well tolerated by cosmonauts for hours even during working activities.
Therefore, a research project has been established between the Russian Academy of Sciences
(Laboratory for Biomedical Problems) and the ARTORG Research Center for Biomedical
Engineering to study the effects of new developed EMS procedures in elderly persons.
Aims:
The aim of trial is to evaluate two types of EMS stimulation (low intensity "conventional
stimulation" vs. high intensity "Russian" stimulation) of legs in comparison with a control
group without EMS in a cohort of elderly patients with severe deconditioning after CHF
decompensation.
METHOTOLOGY:
This prospective, randomized controlled study will use commercially available electronic
stimulator devices (Medel GmbH, Hamburg, Germany) for EMS. For the "Russian" stimulation, an
especial developed stimulator (Amplidin-EST No.5) will be used for frequency modulation of
the stimulation impulse, which is supposed to make stimulation sensation more comfortable.
Supervised EMS training will be performed 5 times per week (weekdays) during 30 minutes over
a period of 6 weeks in elderly deconditioned CHF patients, starting at the Kantonsspital
Olten during the hospitalisation and continued at home. We will include 20 patients in each
group (20 in control group, 20 in low intensity "conventional group and 20 in high intensity
"Russian" group). The control group was preformed to exclude an attention bias in the study
results. The primary endpoint of the study is the difference in maximum oxygen uptake (peak
VO2) and in 6 minutes walking distance between baseline and after 6-weeks EMS training in all
groups (high intensity vs low intensity vs control). The follow-up period is planned for 2
years.
POTENTIAL SIGNIFICANCE:
Exercise capacity and quality of life in severely deconditioned patients with CHF is poor and
life expectancy is low. While the possibilities to improve the poor condition and function of
the heart by pharmaceutical therapies are limited, there is potential to improve the
condition of the peripheral muscles by exercise training. However, a successful aerobic
training is rarely feasible in these patients. Therefore, EMS training may prove to be ideal
tool to improve leg muscle mass and function of elderly patients. Because, CHF patients do
not tolerate most of the existing EMS stimulation protocols, we have developed a new EMS
stimulation protocol. The application is virtually painless and therefore well tolerated over
hours due to a sophisticated stimulation protocol. Therefore, we hope that, this especial for
elderly CHF patients developed training protocol, may improve their daily activity as well as
their quality of life.
