Abstract 17996: One-Year Outcomes of Patients With ST-Segment Elevation Myocardial Infarction According to Eosinophil Blood Count

Abstract

Background: ST-segment elevation myocardial infarction (STEMI) elicits an intense inflammatory response but the relation between eosinophil blood count and outcomes in this setting is not clear. Hypothesis: A difference in eosinophil blood count in patients with STEMI is associated with a different incidence of death or hospitalization for heart failure (HF). Methods: In this retrospective study using the US cohort of 49 healthcare organizations in the TriNetX database, we included 41,945 patients with STEMI (identified by ICD-10-CM code) between January 1, 2012, and June 2, 2022. Patients were divided into two groups according to the median of eosinophil blood count measured 2-3 days after the acute event in our previous study (0.2x103/μL). The Kaplan-Meier method was used to compare the risks of the composite outcome of death or HF hospitalization within the two cohorts. Results: We included 15,725 and 26,220 patients with median eosinophil blood count equal/above and below 0.2x103/μL, respectively. At 1-year follow-up, the risk of death or HF hospitalization was lower in patients with eosinophil blood count above/equal to the median, 0.2x103/μL (13.6% vs 18.9%; Hazard Ratio 0.68, 95% CI [0.64-0.71]; p<0.001). The incidence of the composite outcome at 1 year was 15.3% and 21.5% for patients with median eosinophil blood count equal/above and below 0.2x103/μL, respectively (p<0.001 for the log-rank test). Figure 1. Secondary analysis suggested that this result was driven mainly by lower mortality in the cohort with higher eosinophil count (10.1% vs 14.9%; HR 0.63, 95% CI [0.59-0.67]; p<0.001). Conclusions: In our large 'real world' analysis, a higher eosinophil blood count within the normal range during the acute phase post-STEMI is associated with a better outcome of death or hospitalization for heart failure.