Table 1.

Baseline Characteristics of Eligible Patients According to Enrollment Status and Shunt Assignment.^*

Characteristic	Not Enrolled	Enrolled
		RVPA Shunt	MBT Shunt
No. of infants†	109	274	275
Age — days
At screening	3.1±2.9	3.1±3.2	3.2±3.8
At randomization	—	5.0±4.0	5.1±4.1
Male sex — %	64	63	61
Race or ethnic group — %‡
White	83	79	79
Black	8	15	16
Asian	3	2	2
Hispanic	15	21	16
Other	6	5	3
Birth weight — kg	3.1±0.5	3.1±0.5	3.1±0.6
Gestational age
<38 wk — %	29	24	27
Median — wk (interquartile range)§	38 (37–39)	38 (38–39)	38 (37–39)
Apgar score — median (interquartile range)
At 1 min	—	8 (8–9)	8 (7–9)
At 5 min	—	9 (8–9)	9 (8–9)
Anatomical diagnosis — %
Hypoplastic left heart syndrome	91	87	88
Critical aortic stenosis	0	<1	1
Single RV with systemic outflow obstruction	5	4	4
Right dominant AV canal with systemic outflow    obstruction	3	5	5
Straddling mitral valve with LV hypoplasia and outflow    obstruction	1	<1	0
Other	1	3	2
Any associated anatomical diagnosis — %	25	32	34
Aortic atresia — %	63	62	63
Obstructed pulmonary venous return — %	4	3	4
Size of ascending aorta — cm	—	0.4±0.2	0.4±0.2
Moderate-to-severe tricuspid-valve regurgitation — %	—	10	14

^*Plus–minus values are means ±SD. AV denotes atrioventricular, LV left ventricular, MBT modified Blalock–Taussig, RV right ventricle, and RVPA right ventricle–pulmonary artery.

^†Five infants who were randomly assigned to a shunt but did not undergo the Norwood procedure were excluded. There were no significant differences in characteristics according to shunt assignment.

^‡Percentages may not add up to 100% because of rounding. Race and ethnic group were reported by study personnel; Hispanic patients were also included in other groups.

^§Gestational age was imputed to be 40 weeks for 12 full-term infants.