The Role of Respiratory Syncytial Virus Infection in the Hospitalization and Mortality of Adults with Congestive Heart Failure in Spain, 2018-2022.

(1) Background: Heart failure (HF) is a growing health concern, with decompensations being a major cause of hospital admissions. Respiratory syncytial virus (RSV) infection can trigger HF exacerbations, increasing morbidity and mortality. This study analyzed hospitalizations for HF with RSV infection in Spain from 2018 to 2022 using data from the Spanish Hospital Discharge Database. (2) Methods: We included patients aged ≥40 years with a diagnosis of HF, selecting a matched control group without RSV infection based on the HF diagnostic code position, year of admission, sex, and age. (3) Results: Of 424,413 HF hospitalizations, 0.47% (1988) involved RSV infection. Hospitalizations for HF with RSV increased over time, except for a decline in 2020-2021. ICU admissions and hospital length of stay decreased, but in-hospital mortality and costs remained unchanged. Patients with RSV had fewer comorbidities than those without RSV but experienced a higher mortality, more frequent non-invasive ventilation, longer hospital stays, and greater costs. Factors linked to higher mortality included advanced age, myocardial infarction, SARS-CoV-2 coinfection, and oxygen therapy dependence. RSV infection was independently associated with increased in-hospital mortality. (4) Conclusions: These findings highlight the need for early RSV detection in HF patients to implement preventive measures and reduce severe disease outcomes.