Timing of Influenza Vaccination in Patients With Heart Failure (FLU-HF)

Optimizing the Timing of Influenza Vaccination in Patients With Heart Failure: the FLU-HF Randomized Trial: a Randomized Controlled Trial

Heart failure (HF) is one of the most common causes of hospital admission in Canada and costs the Canadian healthcare system over $1 billion annually. Influenza vaccination is an inexpensive strategy to prevent influenza infections and reduce an important trigger for HF decompensation and hospital readmission. Yet, the optimal timing of vaccine administration remains unclear. When patients with HF are admitted to the hospital with an acute decompensation in advance of, or during, the 'flu season', this can be an ideal time to administer the vaccine. However, patients with acute HF decompensation have significant inflammatory injury, and may have substantially impaired immune responses; thus vaccine administration while admitted during an acute decompensated HF episode may not lead to high anti-influenza antibody titres. A more effective strategy can be to vaccinate after the decompensation has resolved, when patients are more stable. The FLU-HF randomized trial will determine whether administering the influenza vaccine to patients admitted in-hospital with an acute HF decompensation or waiting until they have stabilized as an out-patient leads to an improved anti-influenza response.

Participants will be randomized in a 1:1 manner to receiving the influenza vaccination during their heart failure hospitalization versus receiving the vaccine during their first follow-up in the heart failure clinic.

Participants in this arm will receive the influenza vaccination during their heart failure hospitalization.

Participants in this arm will receive the influenza vaccination during their follow up visit in the heart failure clinic 30 days post-discharge.

There will be approximately 40 participants who consent; they will be randomized in a 1:1 manner to receiving the influenza vaccination during their heart failure hospitalization versus receiving the vaccine during their first follow-up in the heart failure clinic.

Seroconversion will be measured by antibody as assessed by the hemagglutination inhibition (HI) assay.

Seroconversion for one or more strains in the influenza vaccine upto three months following vaccination.

Seroconversion will be measured by antibody as assessed by the hemagglutination inhibition (HI) assay.

Inclusion Criteria: Age > 18 years Admitted in hospital with primary diagnosis of acute HF Prior diagnosis of chronic HF > 3 months prior to admission Not on inotropes, mechanical support, or IV diuretics for 24 hours Able to follow-up within the MUHC HF clinic as per schedule agree to receive influenza vaccination Exclusion Criteria: Any person who does not meet the above criteria and/or who refuses to participate Already received this seasons influenza vaccination Known allergy to influenza vaccination or components of the influenza vaccination Unlikely to survive to discharge as per admitting physician Prior organ transplant Undergoing chemotherapy for active malignancy Currently randomized in another clinical study