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.