Flu vaccines can save the lives of people with cardiovascular disease by reducing heart complications and preventing influenza.
An international study led by researchers at McMaster University and published in The Lancet Global Health found that influenza vaccines greatly reduce both pneumonia and cardiovascular complications in people with heart failure.
“If you have heart failure, you should get the flu vaccine because it can save your life, that’s what we found in this study,” said the study’s principal investigator, Mark Loeb, a professor of pathology and molecular medicine at McMaster and a physician and microbiologist. of Infectious Diseases of Hamilton. “It is underestimated that the flu vaccine can save people from cardiovascular death,” he added.
The study showed that year-round flu vaccination reduced pneumonia by 40 percent and hospitalization by 15 percent in patients with heart failure. During the fall and winter flu season, the flu vaccine reduced deaths by 20 percent in these patients.
Data collected during flu season also showed that the vaccine helped protect against cardiovascular complications, such as heart attacks and strokes.
This collaborative clinical trial between McMaster and the McMaster Population Health Research Institute and Hamilton Health Sciences had researchers following more than 5,000 heart failure patients in 10 countries in Africa, Asia and the Middle East, where few People get vaccinated regularly against influenza. They received either a flu vaccine or a placebo annually between June 2015 and November 2021.
While the flu has long been associated with an increased risk of life-threatening cardiovascular events, Loeb said people with heart failure are already vulnerable to poor health outcomes. Patients with the condition have a 50 percent chance of dying within five years, while 20 percent are hospitalized for cardiovascular complications each year.
“Importantly, we looked at low- and middle-income countries where 80 percent of cardiovascular disease occurs and where flu vaccination rates are low.”
Salim Yusuf, CEO of PHRI and author of the study, said: “The flu vaccine should be part of standard practice in people with heart failure given how simple, affordable and safe it is. “Avoiding one-sixth of heart disease deaths and preventing hospitalizations makes it very cost-effective and that can have a significant clinical and public health impact.”
The study is the first clinical trial of the effectiveness of the flu vaccine in patients with heart failure.
Added value of this study To our knowledge, this is the first placebo-controlled trial of influenza vaccine in patients with heart failure. Although influenza vaccination did not significantly reduce the first or second primary composite outcome, the vaccine reduced all-cause hospitalization by 16% and reduced community-acquired pneumonia by 42%. When, in a prespecified secondary analysis, we looked at events during peak influenza circulation, the first primary outcome (a composite of the first event of death, nonfatal myocardial infarction, or nonfatal stroke) was significantly reduced in participants randomly assigned to receive the influenza vaccine. A similar pattern of fewer events was observed in peak periods of influenza circulation and in seasons during which the strain in the vaccine was similar to the predominant circulating strain. Implications of all available evidence Taken together with previous trials and previous observational studies, the collective data suggest the benefit and importance of vaccinating patients with heart failure against influenza. |
External funding for the study came from the UK Joint Global Health Trials Program and the Canadian Institutes of Health Research. The vaccines used for the study were provided by Sanofi Pasteur.
