Two-year follow-up of the FLU Vaccination Acute Coronary Syndromes (FLUVACS) Registry.

We have previously determined that there is a significant benefit of vaccination against influenza in patients hospitalized due to an acute coronary event. The purpose of this study is to determine whether the observed benefits of vaccination were maintained over a 2-year follow-up among those who were re-vaccinated during the subsequent winter season. During the winter season of 2001, a total of 301 acute coronary patients were prospectively enrolled within 72 hours of the onset of symptoms. Follow-up was conducted at 6 and 12 months. Patients who survived participated in a registry 1 year after the 2nd influenza vaccination period (winter 2002), as a cohort of chronic and stable coronary patients. The incidence of the primary endpoint cardiovascular death at 1 year was significantly lower in patients receiving vaccination than in controls (6% vs 17%, respectively) by intention-to-treat analysis. The relative risk with vaccination in comparison with controls was 0.34; 95% confidence interval, 0.17-0.71; P = 0.002. In the winter of 2002, 116 patients were vaccinated according to their physicians' instructions, and 114 subjects remained unvaccinated. The combined endpoints of total death plus myocardial infarction 1 year later were 4 (3.4%) in the vaccinated group vs 11 (9.7%) among those who were not vaccinated (P = 0.05). Influenza vaccination may reduce the risk of death and ischemic events in patients admitted with acute coronary syndromes. There is also a beneficial trend in the quiescent phase of ischemia.