Thiamine Supplementation to Improve Cardiac Function in Patients With Congestive Heart Failure

Study Overview
=================
Brief Summary
-----------------
Working Hypothesis: a treatment with thiamine improves functional status and heart function of patients with congestive heart failure when on a diuretic treatment.

Detailed Description
-----------------
In the treatment of congestive heart failure, diuretic drugs have become a firm cornerstone of therapy. Up to 50% of patients with congestive heart failure in industrialized nations will undergo long-term diuretic treatment. Diuretic therapy is associated with a loss of water soluble vitamins, including vitamin B1 (thiamine). Electrolyte dysbalance, a major side effect of diuretic therapy, has been extensively studied. In sharp contrast, only few data are available about the effects of vitamin loss and in particular of thiamine in this setting. Available data suggest that a diuretic treatment is associated with an increased risk for thiamine deficiency. Thiamine plays a crucial role for normal cardiac function, since severe thiamine deficiency leads to congestive heart failure (wet beriberi). Consequently, patients undergoing diuretic treatment might have compromised heart function. Supplementation of thiamine has been reported to improve cardiac function in patients with congestive heart failure on long-term treatment with diuretic drugs. However, no efforts have been made to confirm those preliminary observations by a placebo-controlled, double-blind study.

Official Title
-----------------
Thiamine Supplementation to Improve Cardiac Function in Patients With Congestive Heart Failure on Long-term Treatment With Diuretic Drugs

Conditions
-----------------
Heart Failure

Intervention / Treatment
-----------------
* Drug: Thiamine
* Drug: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Patients with stable congestive heart failure on a prescription for diuretic drugs Exclusion Criteria: Acute heart failure Foreseeable need for further changes in medication Current medication containing vitamins Patients with a creatinine above 250 μmol/l

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

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: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Thiamine<br> | Drug: Thiamine<br>* Supplementation of thiamine (vitamin b1) 300 mg per day, once daily, for a duration of 4 weeks<br>|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* Placebo, once daily, for a duration of 4 weeks<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Left ventricular ejection fraction |  | One day, one week, two weeks, four weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quality of life |  | One day, one week, two week, four weeks | 
| 6-minutes walking test |  | One day, one week, two weeks, four weeks |