A randomized controlled trial of influenza vaccine to prevent adverse vascular events.
Medical Research Council
McMaster University
The goal of this study is to assess whether inactivated influenza vaccine can reduce adverse vascular events in high risk participants. We will address the question by randomizing patients at high risk for adverse vascular events to either annual inactivated influenza vaccine or to placebo over three influenza seasons. Participants will aged 18 years and over and have New York Heart Association functional class II, III and IV heart failure. Patients will be randomized to either influenza vaccine or placebo. We will enroll 3,500 participants from centres in seven countries: Philippines (the lead centre), Mozambique, Sudan, Uganda, Saudi Arabia, Malaysia, China. The primary outcome is a composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI), non- fatal stroke, and hospitalization for CHF. We hypothesize that the intervention will lead to a 25% risk reduction in the primary outcome. This proposed randomized trial has important implications for the management of patients at high risk for major adverse vascular events. Although the influenza vaccine is recommended annually for groups with diabetes and cardiovascular disease in many counties, uptake of these recommendations is relatively low. Cardiologists in most jurisdictions do not routinely recommend annual influenza vaccine for their patients as a strategy to reduce future adverse vascular events such as acute coronary syndrome or stroke. Uptake of influenza vaccine in patients with heart disease varies by country but in study sites is 11% on average. Rigorous demonstration of influenza vaccine leading to a reduction in major adverse vascular events would represent a landmark study.
6.1 Pharmaceuticals / Research Grant