Abstract 4360076: Risk of Acute Systolic Heart Failure Following Respiratory Syncytial Virus Compared to Influenza: A Multi-Institutional Retrospective Cohort Study

Background: Respiratory syncytial virus (RSV) has been historically underrecognized as a contributor to non-pulmonary complications in adults. Emerging evidence suggests that RSV, similar to influenza, may exert cardiotropic effects. We aimed to compare the incidence of acute systolic heart failure following RSV and influenza infections using real-world data from a large global health network. Methods: This retrospective cohort study used data from the Global Collaborative Network on the TriNetX platform, encompassing 143 healthcare organizations. Adult patients diagnosed with RSV or influenza between January 1, 2015, and December 31, 2024, were included. Patients with a prior history of heart failure, ischemic heart disease, amyloidosis, or rheumatic mitral valve disease were excluded. Propensity score matching (1:1) was performed to balance cohorts on age, sex, race, diabetes, obesity, and chronic pulmonary disease. Acute systolic heart failure incidence was compared at 30-day and 180-day time windows using risk difference, risk ratio, odds ratio, Kaplan-Meier survival analysis, and hazard ratios. Results: At 30 days, RSV patients had a heart failure incidence of 0.1% compared to 0.038% in influenza (risk ratio 3.84, hazard ratio 3.86; p < 0.001). At 180 days, the RSV group maintained a significantly higher risk (0.2% vs. 0.049%; risk ratio 3.98, hazard ratio 4.07; p < 0.001). Kaplan-Meier analysis confirmed persistently lower heart failure-free survival in the RSV group. While absolute event numbers were small, the relative risk remained nearly fourfold higher across both time frames. Discussion: These findings suggest that RSV carries a significantly elevated risk of acute systolic heart failure compared to influenza, persisting for at least six months post-infection. The consistent results across risk metrics and time windows underscore the systemic effects of RSV and its potential to trigger new-onset heart failure. These insights may warrant enhanced post-viral cardiac monitoring and consideration of expanded prevention strategies, including RSV vaccination, especially in older or at-risk adult populations.