Abstract 368: Association of Atrial Fibrillation with In-hospital Outcomes in ST-Elevation Myocardial Infarction - A Propensity Matched Study

Abstract

Background: Atrial fibrillation is a relatively common comorbid condition in patients with coronary artery disease. However, there are limited data on the association of atrial fibrillation (AF) with outcomes in ST-elevation myocardial infarction (STEMI). Methods: We queried the 2003-2011 Nationwide Inpatient Sample databases using the ICD-9 diagnosis codes, to identify all patients > 18 years admitted with a primary diagnosis of STEMI. We studied the association of AF with in-hospital outcomes in these patients both by regression analysis and propensity match to adjust for demographics, hospital characteristics and co-morbidities. Results: Of the total 452,772 (64.5% men) STEMI hospitalizations, AF was documented in 58,273 (12.9%) cases. Patients with AF were older (mean age 75±12 vs 64±14 years; p<0.001) and had a higher proportion of women (42.5% vs 34.5%; p<0.001) than patients without AF. STEMI patients with AF had a higher risk-adjusted in-hospital mortality (OR 1.15, 95% CI 1.12-1.19, p<0.001), longer average length of stay (7 days vs 4 days, P<0.001) and higher average total hospital charges ($74,082 vs $57,331, P<0.001) than those without AF. Using propensity matching, 57,388 STEMI patients with AF were compared with the same number of patients without AF. Within these matched cohorts, STEMI patients with AF had higher in-hospital mortality (16.7% vs 15.1%, OR 1.13, 95% CI 1.09-1.16; p<0.001), longer average length of stay (7 days vs 6 days, P<0.001), and higher average total hospital charges ($73,832 vs $65,201, P<0.001) than patients without AF. Conclusions: In patients hospitalized with STEMI, AF was independently associated with modestly higher in-hospital mortality, higher hospital charges, and longer length of stay.