Effect of concomitant atrial fibrillation on in-hospital outcomes of non-ST-elevation-acute coronary syndrome-related hospitalizations in the United States

Atrial fibrillation (AF) is the most common arrhythmia in patients presenting with acute coronary syndrome (ACS). The present study examined the rates and trends of clinical outcomes and management strategies of non-ST-elevation ACS (NSTE-ACS) related hospitalizations in the United States, in patients with concomitant AF compared with those in sinus rhythm (SR). We analyzed the "Nationwide Inpatient Sample" database (2004 to 2014) for patients with a primary discharge diagnosis of NSTE-ACS, and further stratified the cohort on the basis of diagnoses into SR and AF groups. Multivariate analysis was performed to examine the association between AF and major adverse cardiovascular and cerebrovascular events (composite of mortality, stroke, and cardiac complications) and its components. Of 4,668,737 NSTE-ACS hospitalizations, 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% (2004) to 19.3% (2014). The AF group was at a greater risk of adverse outcomes with higher rates and adjusted relative risk (RR) of major adverse cardiovascular and cerebrovascular events (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]). Furthermore, the AF group was less likely to receive coronary angiography (47.1% vs 58%) and percutaneous coronary intervention (18.7% vs 32.6%) in comparison to SR (p <0.001 for all outcomes). In conclusion, patients with concomitant AF and NSTE-ACS are less likely to be offered an invasive management strategy for their ACS and are associated with worse complications and higher mortality.