Predictors of postoperative outcomes in infants with low birth weight undergoing congenital heart surgery: a retrospective observational study

Figures & data

Table 1 Diagnosis, operation, and mortality of 114 infants

Diagnosis	Number	Operation	n	Death
CoA ± PDA	8	CoA correction ± PDA ligation	8	1
PA + IVS	5	AP shunt + Brock	4	2
		Reconstruction of RVOT	1
PA + VSD	8	Blalock–Taussig shunt	4	1
		Reconstruction of RVOT	4	1
PS ± ASD or VSD	10	PS correction + ASD/VSD repair	6	1
		PS correction	4
VSD/ASD/PFO	36	VSD/ASD/PFO correction	36	3
ASD + AP window	2	ASD + AP window repair	2
TOF	9	TOF radical correction	3	1
		TOF palliative correction	6	2
TAPVC	6	TAPVC correction	6	3
TGA + IVS	8	Switch	6	1
		Modified Rastelli	1
		Blalock–Taussig	1
TGA + VSD	7	Switch	6	2
		Modified Rastelli	1
CoA + VSD ± ASD	7	CoA correction+VSD± ASD	7	2
PTA ± VSD	4	PTA correction ±VSD repair	4	3
IAA ± VSD	4	IAA correction ±VSD repair	3	1
		IAA correction	1

Abbreviations: PDA, patent ductus arteriosus; CoA, coarctation of aorta; ASD, atrial septal defect; VSD, ventricular septal defect; PFO, patent foramen ovale; TOF, tetralogy of Fallot; TAPVC, total anomalous pulmonary venous drainage; TGA, (complete) transposition of great arteries; IVS, interventricular septum; PA, pulmonary atresia; PS, pulmonary artery stenosis; PTA, permanent trunk of artery; IAA, interruption of aortic arch; AP, aortopulmonary.

Table 2 Univariate risk analysis for hospitalized death in low-birth-weight infants

	Survivors (n=90)	Hospitalized deaths (n=24)	Wilcoxon rank-sum test with continuity correction, P-value
Gestational age (weeks)	36.00±2.87	35.26±3.35	0.346
Birth weight (kg)	1.96±0.43	1.98±0.38	0.9612
Operation weight (kg)	2.20±0.38	2.10±0.31	0.0388
Preoperative stay in NICU (days)	11.39±13.48	13.00±10.98	0.4904
CPB time (minutes)	86.38±59.72	133.67±97.51	0.0244
Clamp time (minutes)	46.08±39.01	72.75±60.37	0.0632
DHCA time (minutes)	4.43±11.75	9.29±18.05	0.2544
Postoperative ventilation time (days)	9.41±17.86	6.00±8.39	0.0043
Postoperative stay time in CICU (days)	3.78±3.49	3.08±3.68	0.0446
Total length of stay (days)	39.76±31.66	19.58±13.29	<0.001
Sex (male)	59 (65.6%)	15 (62.5%)	0.7847
Prematurity	55 (61.1%)	14 (58.3%)	0.8086
Preoperative ventilation	36 (40.0%)	6 (25.0%)	0.1791
Preoperative pulmonary overcirculation	47 (52.2%)	5 (20.8%)	0.0064
Emergency operation	8 (8.9%)	4 (16.7%)	0.2749
STAT risk categories
1	18 (20.0%)	2 (8.3%)	0.1855
2	34 (37.8%)	4 (16.7%)	0.0528
3	16 (17.8%)	2 (8.3%)	0.264
4	19 (21.1%)	15 (62.5%)	<0.001
5	3 (3.3%)	1 (4.2%)	0.8529
Delayed sternal closure	35 (38.9%)	11 (45.8%)	0.5423
Trachea reintubation	19 (21.1%)	2 (8.3%)	0.1547
Unplanned reoperation	19 (21.1%)	5 (20.8%)	0.9804

Abbreviations: NICU, neonatal intensive-care unit; CICU, cardiac ICU; CPB, cardiopulmonary bypass; DHCA, deep hypothermic circulatory arrest; STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery.

Table 3 Multivariate logistic analysis for hospitalized death in low-birth-weight infants

Outcome	Independent variables (p≤0.2)	Adjusted OR	95% CI	P (Z)	Model likelihood-ratio test
Death	Intercept Operation Weight STAT risk Categories	2.83 0.17 1.97	0.07–119.53 0.03–0.85 1.21–3.22	0.5867 0.0312 0.0062	LR 21.40 (χ^2) P<0.0001 (χ^2)

Abbreviation: STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery.

Figure 1 Nomogram prediction of postoperative stay time in CICU.

Abbreviations: STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery; NICU, neonatal intensive-care unit; CICU, cardiac ICU.

Figure 2 Nomogram prediction of postoperative stay time in NICU.

Abbreviations: STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery; NICU, neonatal intensive-care unit

Figure 3 Nomogram prediction of total ICU length of stay.

Notes: Premature — 0 = no, 1 = yes; diagnostic classification — 0 = compound deformity, 1 = univentricular deformity, 2 = biventricular deformity, 3 = macrovascular deformity.
Abbreviations: Pre, preoperative; ICU, intensive-care unit; NICU, neonatal ICU; STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery.

Table S1 Patient characteristics of 114 infants undergoing congenital heart surgery

	Counts(%)
Sex (male)	65% (n=74)
Premature	61% (n=69)
Gestational age (weeks, median)	36.3 (range 25.1–42.0)
Birth weight (kg, median)	2.02 (range 0.9–2.5)
Age at operation (days, median)	27.0 (range 3–97)
Operation weight (kg, median)	2.25 (range 1.1–2.7)
STAT risk categories:
-1	17.5% (n=20)
-2	33.3% (n=38)
-3	15.8% (n=18)
-4	29.8% (n=34)
-5	3.5% (n=4)
CPB (minutes, median)	87.0 (range 0–326, n=112)
Clamp (minutes, median)	44.0 (range 0–195, n=112)
DHCA	19.5% (n=22, n=113)
DHCA (minutes, median)	20.0 (range 0–68, n=113)
Time of sternal closure
-usual	59.6% (n=68)
-delayed	40.4% (n=46)
Unplanned reoperation	21.1% (n=24)
CICU after surgery (days, median)	3.0 (range 0–23)
Mechanical ventilation time after surgery (days, median)	5.0 (range 0–164)
NICU after surgery (days, median)	15.0 (range 0–245)
Total length of stay (days, median)	29.5 (range 0–267)

Abbreviations: NICU, neonatal intensive-care unit; CICU, cardiac ICU; CPB, cardiopulmonary bypass; DHCA, deep hypothermic circulatory arrest; STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery.

Table S2 Cox proportional-hazard model of quantitive outcomes

	Covariates	OR	95% CI
CICU (days)	Sex = 1	2.1353	1.2401–3.489
	Premature = 1	0.6499	1.2401–3.490
	NICU Pre	0.9894	1.2401–3.491
	Diagnostic classification = 1	1.3264	1.2401–3.492
	Diagnostic classification = 2	1.4891	1.2401–3.493
	Diagnostic classification = 3	13.0881	1.2401–3.494
	STAT risk	0.7017	1.2401–3.495
NICU (days)	Gestational age	1.0811	1.2401–3.496
	STAT risk	0.7847	1.2401–3.497
Total stay (days)	Birth weight	1.7423	1.2401–3.498
	NICU Pre	0.9539	1.2401–3.499
	STAT risk	0.7376	1.2401–3.500

Abbreviations: Pre, preoperative; NICU, neonatal intensive care unit; CICU, cardiac ICU; STAT, Society of Thoracic Surgeons–European Association for Cardio-Thoracic Surgery.

Availability of data and material

All data supporting our findings will be shared on request. Contact Sheng Wang via [email protected].