Reduced Left Ventricular Ejection Fraction as a Marker of Vulnerability to Healthcare-Associated Infections in Coronary Care Unit Patients: A Single-Centre Cohort Study

Background/Objectives: Healthcare-associated infections (HAIs) remain an important cause of morbidity in coronary care units (CCUs). Although left ventricular ejection fraction (LVEF) is central to cardiovascular risk stratification, its relationship with infection susceptibility in CCU patients is poorly defined. We explored the association between LVEF and HAI incidence in a real-world CCU population. Methods: We performed a retrospective cohort study including 870 consecutive adult patients admitted to a tertiary CCU. Patients were stratified by LVEF into reduced (<40%) and preserved or mildly reduced (≥40%) groups. HAIs were defined using Centers for Disease Control and Prevention/National Healthcare Safety Network (CDC/NHSN) criteria and required microbiological confirmation. Demographic data, comorbidities, exposure to invasive devices, colonization status and clinical outcomes were collected. Associations with HAIs were assessed using univariate and exploratory multivariable logistic regression. Results: Of the 870 patients, 235 (27.0%) had LVEF < 40%. The overall HAI incidence was 1.8% (16/870) and was significantly higher in patients with reduced LVEF compared with those with LVEF ≥ 40% (3.82% vs. 1.10%, p = 0.018). Patients with LVEF < 40% had greater exposure to invasive devices (OR 2.06, 95% CI 1.52–2.79, p < 0.001). The excess HAI burden was mainly driven by urinary tract infections (1.70% vs. 0.15%, p = 0.021). Colonization rates at admission were similar between groups. In univariate analysis, reduced LVEF was associated with higher HAI occurrence, but it did not remain independently associated after adjustment. Admission infection, malignancy, CPAP use, and CCU length of stay ≥5 days emerged as independent factors in the exploratory multivariable model (Nagelkerke R2 = 0.247). Conclusions: Reduced LVEF is associated with higher HAI incidence in CCU patients, reflecting greater clinical severity, longer hospitalization, and increased exposure to invasive devices. Although not an independent predictor, LVEF appears to function as a clinically useful marker of vulnerability that may support early risk stratification and targeted infection-prevention strategies in CCU settings.