Electrical Stimulation Improves Exercise Tolerance in Patients With Advanced Heart Failure on Continuous Dobutamine Use

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to determine whether neuromuscular electrical stimulation can improve exercise tolerance for patients with heart failure and continuous dobutamine use in a hospital.

Official Title
-----------------
Neuromuscular Electrical Stimulation Improves Exercise Tolerance in Patients With Advanced Heart Failure on Continuous Dobutamine Use - A Randomized Controlled Trial

Conditions
-----------------
Heart Failure, Ventricular Dysfunction, Left

Intervention / Treatment
-----------------
* Device: Neuromuscular Electrical Stimulator
* Other: Physical Therapy Session


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Advanced heart failure (Stage D - Left ventricle ejection fraction <30%) New York Heart Association class III-IV Standard medical therapy for heart failure management Continuous inotropic infusion Exclusion Criteria: Unstable angina pectoris Recent (6 months) acute coronary syndrome Arrythmias Chronic renal failure Diabetes Mellitus Peripheral vascular diseases Inability to walk
Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Usual Care<br>Patients in this group were subject to regular Physical Therapy Sessions in the hospital and each session consisted of breathing exercises and global active exercises of the upper and lower limbs in bed. The treatment was applied twice a day during the hospitalization period. The protocol was interrupted if the patient had signs or symptoms suggestive of poor tolerance to exercise. | Other: Physical Therapy Session<br>* each session consisted of breathing exercises and global active exercises of the upper and lower limbs in bed. The treatment was applied twice a day during the hospitalization period. The protocol was interrupted if the patient had signs or symptoms suggestive of poor tolerance to exercise: 1) cyanosis, pallor, dizziness, nausea or pre-syncope; 2) chest pain; 3) bradycardia; 4) a drop in systolic blood pressure >15 mmHg in comparison to baseline; 5) an excessive rise in systolic blood pressure defined as >200 mmHg; 6) a rise in diastolic blood pressure during exercise >110 mmHg; 7) fatigue rated ≥6/10 on the perceived exertion Borg scale (PEB); and/or 8) electrocardiographic signs of cardiac ischemia or ventricular arrhythmias.<br>|
| Experimental: Neuromuscular Electrical Stimulator<br>Lower limb muscles of both legs were simultaneously stimulated using self adhesive surface rectangular electrodes. During all session period, the patients were maintained in the supine Fowler 45º position. The stimulation intensity was progressively increased according to the patient tolerance until a muscular contraction was observed. Stimulation was performed twice a day; the session duration was 60 min. Heart rate, blood pressure, respiratory rate and pulse oximetry were monitored throughout the sessions, in all patients. | Device: Neuromuscular Electrical Stimulator<br>* Quadriceps and calf muscles of both legs were simultaneously stimulated using self adhesive surface rectangular electrodes. During all session period, the patients were maintained in the supine Fowler 45º position. Stimulation parameters were set up as follows: biphasic current of 40 Hz, 400-µs pulse duration, mode on-time 10s and off-time 20s and maximal amplitude of 60 mA. The stimulation intensity was progressively increased according to the patient tolerance until a muscular contraction was observed. Stimulation was performed twice a day; the session duration was 60 min.<br>* Other names: Functional Electrical Stimulation (FES);|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Functional capacity evaluated using the 6-minute walk test (6MWT) | Functional capacity was evaluated using the 6-minute walk test (6MWT), by a single evaluator blinded to the group allotment, in accordance with American Thoracic Society criteria. | Change from assessment at admission and at patient discharge | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the intravenous inotropic support dosage | For all patients, the inotropic intravenous dose was adjusted daily by a single clinician (prescriber) blinded to the group allocation. Weaning from inotropic support was performed by the prescriber based on the improvement of clinical signs (level of consciousness, peripheral perfusion and blood pressure). | Change from the first day of the protocol and patient discharge |