TY - JOUR

T1 - Optimal timing of influenza vaccination among patients with acute myocardial infarction – Findings from the IAMI trial

AU - Akhtar, Zubair

AU - Götberg, Matthias

AU - Erlinge, David

AU - Christiansen, Evald H.

AU - Oldroyd, Keith G.

AU - Motovska, Zuzana

AU - Erglis, Andrejs

AU - Hlinomaz, Ota

AU - Jakobsen, Lars

AU - Engstrøm, Thomas

AU - Jensen, Lisette O.

AU - Fallesen, Christian O.

AU - Jensen, Svend E.

AU - Angerås, Oskar

AU - Calais, Fredrik

AU - Kåregren, Amra

AU - Lauermann, Jörg

AU - Mokhtari, Arash

AU - Nilsson, Johan

AU - Persson, Jonas

AU - Islam, Abu K.M.M.

AU - Rahman, Afzalur

AU - Malik, Fazila

AU - Choudhury, Sohel

AU - Collier, Timothy

AU - Pocock, Stuart J.

AU - Pernow, John

AU - MacIntyre, Chandini R.

AU - Fröbert, Ole

N1 - Publisher Copyright: © 2023 The Authors

PY - 2023

Y1 - 2023

N2 - Influenza vaccination reduces the risk of adverse cardiovascular events. The IAMI trial randomly assigned 2571 patients with acute myocardial infarction (AMI) to receive influenza vaccine or saline placebo during their index hospital admission. It was conducted at 30 centers in 8 countries from October 1, 2016 to March 1, 2020. In this post-hoc exploratory sub-study, we compare the trial outcomes in patients receiving early season vaccination (n = 1188) and late season vaccination (n = 1344). The primary endpoint was the composite of all-cause death, myocardial infarction (MI), or stent thrombosis at 12 months. The cumulative incidence of the primary and key secondary endpoints by randomized treatment and early or late vaccination was estimated using the Kaplan-Meier method. In the early vaccinated group, the primary composite endpoint occurred in 36 participants (6.0%) assigned to influenza vaccine and 49 (8.4%) assigned to placebo (HR 0.69; 95% CI 0.45 to 1.07), compared to 31 participants (4.7%) assigned to influenza vaccine and 42 (6.2%) assigned to placebo (HR 0.74; 95% CI 0.47 to 1.18) in the late vaccinated group (P = 0.848 for interaction on HR scale at 1 year). We observed similar estimates for the key secondary endpoints of all-cause death and CV death. There was no statistically significant difference in vaccine effectiveness against adverse cardiovascular events by timing of vaccination. The effect of vaccination on all-cause death at one year was more pronounced in the group receiving early vaccination (HR 0.50; 95% CI, 0.29 to 0.86) compared late vaccination group (HR 0.75; 35% CI, 0.40 to 1.40) but there was no statistically significant difference between these groups (Interaction P = 0.335). In conclusion, there is insufficient evidence from the trial to establish whether there is a difference in efficacy between early and late vaccination but regardless of vaccination timing we strongly recommend influenza vaccination in all patients with cardiovascular diseases.

AB - Influenza vaccination reduces the risk of adverse cardiovascular events. The IAMI trial randomly assigned 2571 patients with acute myocardial infarction (AMI) to receive influenza vaccine or saline placebo during their index hospital admission. It was conducted at 30 centers in 8 countries from October 1, 2016 to March 1, 2020. In this post-hoc exploratory sub-study, we compare the trial outcomes in patients receiving early season vaccination (n = 1188) and late season vaccination (n = 1344). The primary endpoint was the composite of all-cause death, myocardial infarction (MI), or stent thrombosis at 12 months. The cumulative incidence of the primary and key secondary endpoints by randomized treatment and early or late vaccination was estimated using the Kaplan-Meier method. In the early vaccinated group, the primary composite endpoint occurred in 36 participants (6.0%) assigned to influenza vaccine and 49 (8.4%) assigned to placebo (HR 0.69; 95% CI 0.45 to 1.07), compared to 31 participants (4.7%) assigned to influenza vaccine and 42 (6.2%) assigned to placebo (HR 0.74; 95% CI 0.47 to 1.18) in the late vaccinated group (P = 0.848 for interaction on HR scale at 1 year). We observed similar estimates for the key secondary endpoints of all-cause death and CV death. There was no statistically significant difference in vaccine effectiveness against adverse cardiovascular events by timing of vaccination. The effect of vaccination on all-cause death at one year was more pronounced in the group receiving early vaccination (HR 0.50; 95% CI, 0.29 to 0.86) compared late vaccination group (HR 0.75; 35% CI, 0.40 to 1.40) but there was no statistically significant difference between these groups (Interaction P = 0.335). In conclusion, there is insufficient evidence from the trial to establish whether there is a difference in efficacy between early and late vaccination but regardless of vaccination timing we strongly recommend influenza vaccination in all patients with cardiovascular diseases.

KW - Influenza vaccination

KW - Myocardial infarction

KW - Optimal timing

KW - Percutaneous coronary intervention

KW - Vaccine effectiveness

U2 - 10.1016/j.vaccine.2023.10.028

DO - 10.1016/j.vaccine.2023.10.028

M3 - Journal article

C2 - 37925315

AN - SCOPUS:85176266634

VL - 41

SP - 7159

EP - 7165

JO - Vaccine

JF - Vaccine

SN - 0264-410X

IS - 48

ER -