In-hospital outcomes among patients admitted for myocardial infarction with coexisting respiratory syncytial virus versus influenza infections

Among patients with myocardial infarction, influenza infection increases the risk of severe complications and mortality, likely driven by combined inflammatory and cardiovascular stress. Little is known about coexisting respiratory syncytial virus (RSV) infection among those presenting with myocardial infarction. This study aimed to investigate whether in-hospital outcomes differ among patients admitted for myocardial infarction with coexisting RSV versus influenza infections. Using the 2016-2022 United States National Inpatient Sample, we identified all individuals admitted for myocardial infarction. Only those with coexisting RSV or influenza infections were included. In-hospital outcomes were compared among those with RSV versus influenza. We identified 3966 patients with myocardial infarction in the database meeting our inclusion criteria, of which 565 had coexisting RSV and 3401 had coexisting influenza infections. In-hospital mortality occurred in 5.7% of individuals with RSV and 5.8% of individuals with influenza infections. The average length of hospital stay in all patients was approximately 7 days for both those with RSV and those with influenza. After adjusting for covariates, there was no difference in mortality (odds ratio [OR] = 0.925;95% confidence interval [CI] = 0.620-1.382), in-hospital complications (OR = 0.973;95%CI = 0.738-1.282), or LOS (mean difference = 0.17; 95%CI = - 0.30 to 0.64). In conclusion, this study found no significant difference in in-hospital mortality or length of stay between patients with myocardial infarction coexisting with RSV versus influenza infections. Given the established role of influenza in exacerbating myocardial infarction severity, greater recognition and investigation of RSV co-infections in this high-risk population are likely needed.