Various professional societies including the Canadian Cardiovascular Society recommend the use of the influenza vaccine in patients with cardiac diseases. However the uptake of this intervention, attitudes of patients, and beneficial effects of this intervention in patients with cardiac disease is unclear.
All patients with ICDs presenting for follow up at the Sunnybrook Hospital ICD clinic between September 1st 2011 and November 31st 2011 were approached to complete a survey assessing patient demographics and co-morbidities, use of the influenza vaccine in the preceding year and views towards the influenza vaccine. All ICD clinic charts were reviewed to determine the presence and extent of all ICD therapies (appropriate and inappropriate) in five months preceding the 2010 influenza season (June 1st 2010 - October 31st 2010) and three months approximating the 2010-2011 influenza season (December 1st 2010 - March 1st 2011).
229 patients completed surveys. 179 (78%) patients reported receiving the influenza vaccination in the previous year. Patients who received the influenza vaccine were older than those who did not (70.8 vs. 64.8 years, P=0.0005). There was no difference in the self-reported prevalence of coronary artery disease, diabetes, renal disease, and prior stroke in patients reported receiving versus not receiving the influenza vaccine. Patients who received the influenza vaccine were more likely to disagree with the statements “The Flu shot is not effective” and “The Flu shot will make me sick” compared to individuals not receiving the influenza vaccine, and planned to obtain the influenza vaccine in the upcoming year (95.2% vs. 34.8%, P<0.0001). Thirty nine (17.0%) individuals in the overall cohort received at least one ICD therapy during the two pre-defined periods - 10.6% who received the influenza vaccine received at least 1 ICD therapy during influenza season compared to 13.7% who did NOT receive the influenza vaccine (P=NS). The average number of ICD therapies/person during influenza season was greater in individuals not receiving the influenza vaccination compared to individuals who did receive the influenza even after adjusting for the number of ICD therapies received in the pre-influenza period (0.45 therapies vs. 0.14 therapies, P=0.0006).
A large proportion of patients with ICDs receive the influenza vaccine. Receipt of the influenza vaccine may be associated with a reduction in ICD therapies during influenza season.
© 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.