LAUSR

Atrial fibrillation (AF) is the most common arrhythmia in patients presenting with acute coronary syndrome (ACS). We sought to examine the rates, trends, and clinical outcomes of non-ST Elevation acute coronary syndrome (NSTE-ACS) related hospitalisations in the United States in patients with AF compared to those with sinus rhythm (SR). We analysed the Nationwide Inpatient Sample (NIS) database from 2004 to 2014 for patients with a primary discharge diagnosis of NSTEMI or UA, and further stratified the cohort on the basis of diagnoses into SR and AF groups. Multivariate analysis was performed to identify the association between AF and MACCE (composite of mortality, stroke and cardiac complications), mortality, stroke, and bleeding. A total of 4,668,737 NSTE-ACS admissions were included in our analysis. The proportions of SR and AF groups were 82.4% (3,848,202) and 17.6% (820,535), respectively. The incidence of AF increased significantly over time from 16.5% in 2004 to 19.3% in 2014 (p<0.001). The AF group was at a greater risk of adverse outcomes with higher overall rates and adjusted relative risk of MACCE (12.9% vs. 5.3%; RR: 1.74 [1.72, 1.75]), mortality (6.5% vs. 3.3%. RR: 1.12 [1.11, 1.13]), stroke (2.7% vs. 1.5%; RR: 1.32 [1.30, 1.34]) and bleeding (14.7% vs. 8.8%; RR: 1.42 [1.41, 1.43]). The AF group was less likely to receive coronary angiography (47.1% vs. 58%) and PCI (18.7% vs. 32.6%) and more likely to undergo CABG (13.9% vs. 7.6%) in comparison to SR. Figure 1. Crude rates of adverse events The prevalence of concomitant Atrial Fibrillation amongst patients presenting with NSTE-ACS has increased over a decade. However, this high-risk group remains less likely to receive invasive coronary management for NSTE-ACS than patients with sinus rhythm, independent of their comorbidities, and are associated with worse clinical outcomes.