Do outcomes for patients with heart failure vary by emergency department volume?

BACKGROUND Heart failure is a common Emergency Department (ED) presentation but whether ED volume influences patient outcomes is unknown. METHODS AND RESULTS Retrospective cohort of all adults presenting to 93 EDs between 1999 and 2009 with a most responsible diagnosis of heart failure (n=44 925 ED visits; mean age, 76.4 years). Cases seen in low-volume EDs had less comorbidities and were less likely to be hospitalized (54.5%) than those seen in medium (61.8%; adjusted odds ratio [aOR] 1.16, [95% confidence interval {CI} 1.10-1.23]) or high-volume EDs (73.6%; aOR, 1.95 [95% CI, 1.83-2.07]). Of patients treated and released, low-volume ED cases exhibited higher risk of death/hospitalization/ED visit in the subsequent 7 (22.0%) and 30 days (44.9%) than medium (16.3%; aOR, 0.81 [95% CI, 0.73-0.90], and 35.3%; aOR, 0.79 [95% CI, 0.73-0.86]) or high-volume ED cases (13.0%; aOR, 0.69 [95% CI, 0.61-0.78], and 30.2%; aOR, 0.67 [95% CI, 0.61-0.74]). Of patients hospitalized at the time of their index ED visit, low-volume ED cases exhibited a higher risk of 30-day death/all-cause readmission (24.3%) than those seen in medium (21.9%; aOR, 0.83 [95% CI, 0.76-0.91]) or high-volume EDs (18.1%; aOR, 0.77 [95% CI, 0.70-0.85]). CONCLUSIONS Low-volume EDs were more likely to discharge patients with heart failure home, but low-volume ED cases exhibited worse outcomes (driven largely by readmissions or repeat ED visits). Interventions to improve management of acute heart failure are required at low-volume sites.