Risk of in-hospital cardiovascular events according to type of respiratory viral infection: comparison between RSV, influenza and virus-negative patients

Introduction Respiratory viral infections are associated with an increased risk of cardiovascular events during hospitalization. However, it remains unclear whether this risk differs according to the specific viral etiology and whether these associations persist after adjustment for clinical severity. Purpose The objective was to compare the risk of in-hospital cardiovascular events among adults hospitalized with respiratory syncytial virus (RSV) infection, influenza, or a negative viral test. Methods An observational study was conducted in hospitalized adults, classified into three groups according to respiratory viral etiology: RSV, influenza, or virus-negative controls. The latter were defined as patients presenting with febrile syndrome or acute respiratory infection and testing negative for RSV, influenza and SARS-CoV-2, including those with alternative identified etiologies. The primary outcome was a composite of in-hospital cardiovascular events, including ischemic stroke, acute coronary syndrome, heart failure, and venous thromboembolic disease. To reduce confounding by severity, a multinomial propensity score based on SOFA was estimated, and inverse probability of treatment weighting (IPTW) with stabilized weights was applied. In the weighted cohort, univariable and multivariable logistic regression models adjusted for age and SOFA were performed, including an interaction model with SOFA. Sensitivity analyses were conducted to assess the robustness of the estimates, including additional adjustment for the Charlson Comorbidity Index, estimation with robust variances, and analyses with truncation of extreme weights (p99 and p95), with adjustment for SOFA . Results A total of 666 patients were included: 234 virus-negative, 205 with RSV, and 227 with influenza. Adequate balance between groups was achieved after IPTW weighting. In the weighted multivariable analysis adjusted for age and SOFA, RSV infection was associated with a higher risk of in-hospital cardiovascular events compared with virus-negative patients (OR 1.98; 95% CI 1.20–3.28), whereas influenza was not significantly associated (OR 1.10; 95% CI 0.68–1.80)(Graphical abstract). Moreover, RSV was associated with a higher risk compared with influenza (OR 1.80; 95% CI 1.13–2.88). No significant interaction was observed between viral group and SOFA. Findings remained consistent across sensitivity analyses (figure 1). Conclusion Among hospitalized adults, RSV infection was associated with a higher risk of in-hospital cardiovascular events compared with both virus-negative patients and those with influenza, independently of clinical severity. These findings suggest a differential cardiovascular risk profile according to respiratory viral etiology, with potential implications for clinical risk stratification and in-hospital management.