Influenza vaccination strategy in acute coronary syndromes: the VIP-ACS trial . (28th August 2022) - Fonseca, Henrique Andrade R
Abstract: Aims: To evaluate whether a strategy of double-dose influenza vaccination during hospitalization for an acute coronary syndrome (ACS) compared with standard-dose outpatient vaccination (as recommended by current guidelines) would further reduce the risk of major cardiopulmonary events. Methods and results: Vaccination against Influenza to Prevent cardiovascular events after Acute Coronary Syndromes (VIP-ACS) was a pragmatic, randomized, multicentre, active-comparator, open-label trial with blinded outcome adjudication comparing two strategies of influenza vaccination following an ACS: double-dose quadrivalent inactivated vaccine before hospital discharge vs. standard-dose quadrivalent inactivated vaccine administered in the outpatient setting 30 days after randomization. The primary outcome was a hierarchical composite of all-cause death, myocardial infarction, stroke, unstable angina, hospitalization for heart failure, urgent coronary revascularization, and hospitalization for respiratory causes, analysed by the win ratio method. Patients were followed for 12 months. During two influenza seasons, 1801 participants were included at 25 centres in Brazil. The primary outcome was not different between groups, with 12.7% wins in-hospital double-dose vaccine group and 12.3% wins in the standard-dose vaccine group {win ratio: 1.02 [95% confidence interval (CI): 0.79–1.32], P = 0.84}. Results were consistent for the key secondary outcome, a hierarchical composite of cardiovascular death, myocardial infarction and stroke [win ratio: 0.94 (95% CI: 0.66–1.33), P = 0.72]. Time-to-first event analysis for the primary outcome showed results similar to those of the main analysis [hazard ratio 0.97 (95% CI: 0.75–1.24), P = 0.79]. Adverse events were infrequent and did not differ between groups. Conclusion: Among patients hospitalized with an ACS, double-dose influenza vaccination before discharge did not reduce cardiopulmonary outcomes compared with standard-dose vaccination in the outpatient setting. Clinical Trial Registration: ClinicalTrials.gov number: NCT04001504 Structured Graphical Abstract: Structured Graphical Abstract Summary of the Vaccination against Influenza to Prevent cardiovascular events after Acute Coronary Syndromes (VIP-ACS) main findings. Among patients hospitalized for ACS, in-hospital double-dose influenza vaccination did not reduce the rates of major cardiovascular and pulmonary events at 12 months as compared with standard-dose vaccination 30 days after randomization. ( Left panel ) Summary of the design and primary outcome of the VIP-ACS trial. ( Right upper figure ) The primary outcome was a hierarchical composite analysed by unmatched win ratio method. ( Right lower figure ) The primary outcome was a time-to-event analysis with the use of unadjusted Cox proportional hazards models.