Udell, Jacob (Department of Medicine, Women’s College Hospital)
Mentor: Farkouh, Michael E.
Network Affiliation: Canadian Vascular Network
1. The health problem/issue
Patients with heart attack or heart failure are at increased risk of heart and respiratory health complications from influenza (‘flu’). Our group has previously shown that the influenza vaccine may reduce the risk of these complications. However, such high-risk patients in fact receive the lowest protection from the flu vaccine due to a reduced immune response from mild immune system suppression among the elderly and individuals with heart disease compared with healthy young people.
2. The objective
To address this problem, we are conducting a large clinical trial among patients stabilized after a heart attack or congestive heart failure. We are comparing the risk of developing short- and long-term heart and respiratory health complications among patients treated with a standard flu vaccine with a higher dose flu vaccine. The objective of this grant is to get a blood test from patients before and a month after receiving these flu shots to test whether high dose flu vaccine, compared with the standard flu shot, boosts people’s antibody response to flu. We will also compare the effects of each flu shot on other circulating protein markers of immunity, heart function, and inflammation.
3. The approach
We are conducting a large double-blind clinical trial called INVESTED (www.investedtrial.org), in which 9300 patients will be asked if they would like to participate in the blood test and antibody measurement substudy before being vaccinated by one of two different flu vaccine strategies described above. Among these participants, we will identify 3000 patients to provide a blood test sample at the beginning of the study and one month after vaccination. We will repeat these tests every year to determine: 1) if different vaccine strategies significantly boost the immune system response and effects other measurements of the body’s response to vaccination; 2) if these blood tests predict which patients will develop heart or respiratory health complications over the course of the study; 3) if blood test responses change year to year and whether these changes also influence the risk of developing complications.
4. The unique factors
No one has previously determined whether our immune system response to the flu vaccine predicts which patients will develop heart or respiratory health complications in the ensuing year or longer term. Also, it is unclear whether other biological processes are affected by a higher dose flu vaccine, which may also contribute to protection from heart or respiratory health complications.
5. How the project is relevant to the objectives of the initiative
Measuring these biologic responses will provide important insights into how the flu vaccine works to protect high-risk cardiac patients from heart disease, stroke, or respiratory health complications.
6. The impact
Certain biologic responses may predict which patients will develop heart disease, stroke, or respiratory health complications better than simply a high-dose flu vaccine for all strategy (which is a more expensive option). If so, in the near future we can personalize who we recommend receive a standard flu shot and which higher risk patients most benefit from a higher dose flu vaccine. By personalizing therapy, we tailor the right treatment to the right patient at the right time to improve the health and quality of life of patients with heart disease while saving money for the health care system.