Predicting cardiovascular intensive care unit readmission after cardiac surgery: derivation and validation of the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) cardiovascular intensive care unit clinical prediction model from a registry cohort of 10,799 surgical cases

Table 1 Clinical characteristics of cardiac surgical patients with and without a cardiovascular intensive care unit readmission

Characteristic	No readmission (n = 10,320)	Readmission (n = 479)	P value
Demographics
Age, mean (SD), years	64.6 (12.7)	68.9 (12.9)	<0.001
Male, %	75.8	71.0	0.17
BMI, mean (SD), kg/m²	28.9 (5.9)	28.5 (5.5)	0.112
Medical history, %
Hypertension	77.5	81.6	0.035
Dyslipidemia	89.7	88.3	0.315
Type 1 diabetes	1.0	1.9	0.063
Type 2 diabetes	29.4	35.9	0.002
Prior myocardial infarction	45.1	45.5	0.86
Prior PCI	14.2	13.2	0.537
Prior CABG	3.0	6.5	<0.001
Heart failure	15.7	29.0	<0.001
NYHA class
Class I	7.0	4.0	<0.001
Class II	13.9	12.1
Class III	15.6	19.4
Class IV	4.3	7.5
Not entered	59.1	57.0
Cerebrovascular disease	12.5	17.5	0.001
Current smoker	24.7	23.4	0.525
Chronic lung disease	32.6	52.4	<0.001
Chronic liver disease	1.0	3.5	<0.001
Chronic renal failure	2.2	5.8	<0.001
Preoperative dialysis	1.4	2.9	0.005
Preoperative investigations
Extent of coronary artery disease (≥70%), %			0.452
0	17.9	18.4
1 or 2	11.9	14.0
3	38.6	34.9
Left main	21.9	22.3
Not available	9.7	10.4
Left ventricular ejection fraction, %			<0.001
>50%	35.3	23.2
>35-50%	17.1	14.8
>20-34%	4.2	7.5
<20%	1.0	3.3
Not done due to emergency surgery	15.9	21.3
Not available	26.5	29.9
Hemoglobin, mean (SD), g/L	136.3 (18.5)	128.0 (20.8)	<0.001
Creatinine, mean (SD), μmol/L	100.6 (65.4)	116.4 (81.1)	<0.001

BMI: body mass index; CABG: coronary artery bypass graft; NYHA: New York Heart Association; PCI: percutaneous coronary intervention; SD: standard deviation.

ISSN: 1364-8535