Comparison of Heart Failure Hospitalizations with and Without Respiratory Syncytial Virus: A Nationwide Administrative Data Analysis

<b>Background:</b> Heart failure (HF) remains a major cause of hospitalizations in the United States (US). Respiratory syncytial virus (RSV) has been associated with HF exacerbations. We compared in-hospital outcomes and healthcare utilization among US HF hospitalizations with and without RSV. <b>Methods:</b> Using the Nationwide Readmissions Database (2016-2022), we propensity-matched HF hospitalizations with a secondary diagnosis of RSV (HF-RSV) 1:1 to those without RSV (HF-noRSV). Multivariable logistic and Poisson regression models were used to assess associations between RSV and outcomes. The primary outcome was in-hospital mortality; secondary outcomes included adverse events, length of stay (LOS), hospitalization costs, and 30-day readmissions. <b>Results:</b> Among 11,158,836 HF hospitalizations, 32,419 (0.29%) had RSV. Compared with matched HF-noRSV hospitalizations, HF-RSV was associated with higher odds of in-hospital mortality (adjusted odds ratio [aOR] 1.12; 95% CI 1.04-1.20), septic shock (aOR 1.40; 95% CI 1.29-1.52), acute respiratory failure (aOR 3.43; 95% CI 3.32-3.55), and noninvasive mechanical ventilation (aOR 2.15; 95% CI 2.04-2.26). HF-RSV had lower odds of cardiogenic shock (aOR 0.82; 95% CI 0.73-0.92), ventricular tachycardia/fibrillation (aOR 0.73; 95% CI 0.68-0.78), ischemic stroke (aOR 0.31; 95% CI 0.27-0.36), transient ischemic attack (aOR 0.33; 95% CI 0.25-0.44), and 30-day readmissions (aOR 0.54; 95% CI 0.46-0.56). HF-RSV hospitalizations had higher costs (adjusted coefficient 0.02; 95% CI 0.01-0.02) and longer LOS (adjusted coefficient 0.14; 95% CI 0.13-0.14). <b>Conclusions:</b> Among US HF hospitalizations, RSV was associated with higher mortality and respiratory-related complications and increased healthcare resource utilization.