Table 1. Baseline Characteristics of the Index Heart Failure Cohort.

Characteristic	Patients (N = 40,317)
Age, mean ± SD (years)	79.7 ± 7.9
Female	22,492 (55.8%)
Race
Black	4096 (10.2%)
Other	36,221 (89.8%)
Medical history
Anemia on the basis of standardized lab assessments	7301 (18.1%)
Atrial arrhythmia	14,650 (36.3%)
Chronic obstructive pulmonary disease	11,259 (27.9%)
Chronic renal insufficiency	7476 (18.5%)
Coronary artery disease/ischemic heart disease	21,041 (52.2%)
Depression	4131 (10.2%)
Diabetes mellitus	15,844 (39.3%)
Current or previous treatment for hyperlipidemia	13,943 (34.6%)
Current or previous treatment for hypertension	28,745 (71.3%)
Peripheral vascular disease	5684 (14.1%)
Prior cerebrovascular accident/transient ischemic attack	6832 (16.9%)
Smoker within the past year	3632 (9.0%)
Clinical measures at admission
Systolic function
Preserved systolic function	20,128 (49.9%)
Left ventricular systolic dysfunction	14,841 (36.8%)
Missing	5348 (13.3%)
Serum creatinine, mean ± SD (mg/dL)	1.7 ± 2.2
Systolic blood pressure, mean ± SD (mm Hg)	141.7 ± 30.6
Serum sodium, mean ± SD (mEq/L)	137.3 ± 8.2
Hemoglobin, mean ± SD (g/dL)	12.1 ± 5.8
Length of stay for the index hospitalization (days)
Mean ± SD	5.5 ± 4.7
Median (interquartile range)	4.0 (3.0-7.0)
Index year
2003	9319 (23.1%)
2004	14,551 (36.1%)
2005	6445 (16.0%)
2006	10,002 (24.8%)