Preoperative White Blood Cell Count and Risk of 30-Day Readmission after Cardiac Surgery

Table 1

Characteristics of patients with or without 30-day readmission.

Characteristic	30-day readmission
	No	Yes	𝑃 value
Number of patients (2,176)	1,917	259
Demographics
Age	66.2±11.2	66.4±11.5	0.740
Female	28.5	32.8	0.154
BMI	29.6±5.9	29.8±6.5	0.585
Comorbidities
Type 2 diabetes mellitus	31.5	37.1	0.070
Vascular disease	27.3	30.9	0.224
COPD	15.6	20.5	0.043
History of dialysis	2.4	5.0	0.015
Smoking	21.4	22.4	0.726
Cardiac history
Recent MI	17.3	13.1	0.091
CHF	19.9	25.1	0.051
Prior CABG	3.9	2.7	0.337
Prior valve	1.5	1.9	0.611
Prior PCI	18.2	17.4	0.760
NYHA Class IV	15.6	15.4	0.949
Cardiac anatomy and function
Left main disease ≥50%	28.8	20.9	0.007
Single-vessel disease	33.5	42.6	0.002
Two-vessel disease	28.5	30.2
Three-vessel disease	38.1	27.3
Ejection fraction
<40%	11.3	12.3	0.894
40%–59%	12.6	11.1
50%–59%	24.3	24.2
≥60%	51.7	52.4
White blood cell count (in 1,000's, mm^3)
<6.0	19.9	19.7	0.037
6.0–7.9	39.2	35.9
8.0–9.9	25.3	21.6
10.0–12.0	9.9	13.1
>12.0	5.6	9.7

COPD: chronic obstructive pulmonary disease; MI: myocardial infarction; CHF: congestive heart failure; CABG: coronary artery bypass graft surgery; PCI: percutaneous coronary intervention; WBC: white blood cell; eGFR: estimated glomerular filtration rate.