loading . . . Influenza Vaccination After Myocardial Infarction: A Randomized, Double-Blind, Placebo-Controlled, Multicenter Trial | Circulation Background: Observational and small, randomized studies suggest that influenza vaccine may reduce
future cardiovascular events in patients with cardiovascular disease. Methods: We conducted an investigator-initiated, randomized, double-blind trial to compare
inactivated influenza vaccine with saline placebo administered shortly after myocardial
infarction (MI; 99.7% of patients) or high-risk stable coronary heart disease (0.3%).
The primary end point was the composite of all-cause death, MI, or stent thrombosis
at 12 months. A hierarchical testing strategy was used for the key secondary end points:
all-cause death, cardiovascular death, MI, and stent thrombosis. Results: Because of the COVID-19 pandemic, the data safety and monitoring board recommended
to halt the trial before attaining the prespecified sample size. Between October 1,
2016, and March 1, 2020, 2571 participants were randomized at 30 centers across 8
countries. Participants assigned to influenza vaccine totaled 1290 and individuals
assigned to placebo equaled 1281; of these, 2532 received the study treatment (1272
influenza vaccine and 1260 placebo) and were included in the modified intention to
treat analysis. Over the 12-month follow-up, the primary outcome occurred in 67 participants
(5.3%) assigned influenza vaccine and 91 participants (7.2%) assigned placebo (hazard
ratio, 0.72 [95% CI, 0.52–0.99]; P=0.040). Rates of all-cause death were 2.9% and 4.9% (hazard ratio, 0.59 [95% CI,
0.39–0.89]; P=0.010), rates of cardiovascular death were 2.7% and 4.5%, (hazard ratio, 0.59 [95%
CI, 0.39–0.90]; P=0.014), and rates of MI were 2.0% and 2.4% (hazard ratio, 0.86 [95% CI, 0.50–1.46];
P=0.57) in the influenza vaccine and placebo groups, respectively. Conclusions: Influenza vaccination early after an MI or in high-risk coronary heart disease resulted
in a lower risk of a composite of all-cause death, MI, or stent thrombosis, and a
lower risk of all-cause death and cardiovascular death, as well, at 12 months compared
with placebo. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02831608. https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.121.057042
