Thiamine Supplementation in Heart Failure: a Pilot Randomized Controlled Crossover Trial

Inclusion criteria

• Age ≥60
• NYHA class II-IV symptoms
• Recent HF-related admission in past 12 months OR NT-proBNP >600ng/L within 60 days of screening
• LVEF ≤45% on 2D/3D echocardiography or radionuclide angiography (RNA) in the past 12 months (on optimal therapy)
• Medically optimized prior to enrolment with angiotensin converting enzyme inhibitor or angiotensin receptor blocker (± neprilysin inhibitor), β-blocker, and/or aldosterone antagonist at target or maximally tolerated doses.
• Patients must be stable on medications without hospitalization in the past month.

Exclusion criteria

• Taking >2.5mg/d of thiamine supplement. Allows standard multivitamin. B complex vitamin not allowed due to high thiamine content.
• Unable to swallow study medication. A placebo swallowing test will take place at screening.
• Clinical indication for thiamine supplementation including symptomatic thiamine deficiency (Wernicke's encephalopathy, severe malnutrition, refeeding syndrome) and heavy alcohol use, >15 standard drinks per week in men and >10 standard drinks per week in women.
• End-stage renal disease on dialysis
• Severe mitral valve disease because this impacts the accuracy of speckle tracking analysis on echocardiography.
• Non-English speaking (unable to complete questionnaires).
• Unable to provide written consent.
• Cognitive impairment without a caregiver administering medications.
• Expected survival <1 year due to non-cardiac disease.
• Expected heart transplantation in <6 months (± left ventricular assistive device).
• Allergies to the ingredients of the study medication or placebo