Original paper
The protective effect of influenza vaccination on the clinical course of coronary disease in patients with acute coronary syndromes treated by primary PCI – a report from FLUCAD study

Background and aim: We compared the protective effect of influenza vaccination on the clinical course of coronary artery disease (CAD) in patients (pts) with acute coronary syndrome (ACS) treated by primary angioplasty (PCI), and in stable angina pts.
Methods: Prospective, randomized 1 : 1, double-blind, placebo controlled study. We included 658 optimally treated CAD pts; 477 men, mean age 59.9 ± 10.3 years. Median follow-up was 298 (interquartile range 263-317) days.
Results: There were 157 pts (83 – active vaccine, 74 – placebo) vaccinated after primary PCI in ACS, and 501 pts (242 – vaccine, 259 – placebo) with stable angina. In stable angina pts there were no significant differences in estimated 12-month cumulative event rates between vaccinated and placebo groups for the: primary endpoint (cardiovascular death), secondary endpoints: major adverse cardiac event (MACE) – (cardiovascular death or myocardial infarction or coronary revascularization) and coronary ischemic event (composite of MACE or hospitalization for angina). In ACS group, in vaccinated pts we observed: (1) a significant reduction in the rate of coronary ischemic event with HR 0.37 (95% CI 0.14-0.99, p = 0.047); (2) a statistical trend for reduction of MACE with HR 0.36 (95% CI 0.09-1.39; p = 0.139); (3) no effect on cardiovascular mortality.
Conclusions: The protective effect of influenza vaccination on CAD clinical course was observed in pts with ACS but not in those with stable angina. Influenza vaccination may be safely performed immediately after ACS and primary PCI.