The influenza vaccine could be an important treatment for maintaining heart health and warding off cardiovascular events such as stroke and myocardial infarction, according to a meta-analysis.
Researchers examined published clinical trials dating back to the 1960s and found that the flu vaccine provided an approximate 50% reduction in the risk of a major cardiac event, compared with placebo, after one year of follow-up. The vaccine reduced death from any cause by about 40%.
The vaccine reduced cardiovascular events and cardiovascular death in people with or without heart disease.
“For those who had the flu shot, there was a pretty strong risk reduction,” Jacob Udell, MD, the studys lead investigator and a cardiologist at Womens College Hospital and the University of Toronto, said in a news release.
The analysis included a total of 3,277 patients, with an almost equal split between patients with and without established heart disease. Half the participants were randomly assigned to receive flu vaccine, and those that did not typically received a placebo vaccine.
Udell said the results provide support for current guideline recommendations for influenza vaccination of individuals with a prior MI, but for a different reason than simply reducing flu risk. And although the reduction in nonfatal cardiac events was encouraging, he believes a large, lengthier multinational study would comprehensively demonstrate the vaccines effectiveness to reduce fatal cardiac events and save lives.
Beneficial for those with ICDs
A second study, conducted by cardiologists Ramanan Kumareswaran, MD, and Sheldon Singh, MD, from Sunnybrook Health Sciences Centre, examined the use of the influenza vaccine in patients with implantable cardiac defibrillators.
“Anecdotes suggest that patients have more ICD shocks during flu season,” Kumareswaran said. “We were trying to figure out what we can do to reduce the amount of shocks in [our clinics]ICD population during flu season.”
Patients with ICDs who had appointments at the Sunnybrook Hospital ICD clinic between Sept. 1, 2011, and Nov. 30, 2011, completed a survey that identified their demographics, health status, whether they received a flu shot in the past year and opinions towards the vaccine.
Patients who did not receive the flu vaccine tended to experience more ICD therapies on average: 10.6% of patients who received the vaccine received at least one ICD therapy during flu season, compared with 13.7% of patients who did not receive the vaccine.
“What is interesting is that if this is consistent over time, it could be of significant benefit to our patient population who already have compromised survival to start with,” Singh said. “We would like to look at this on a larger scale to determine whether or not our results can be replicated. Were in the process to determine best how to do that.”
Both studies were presented at the Canadian Cardiovascular Congress, which took place Oct. 27-31 in Toronto.