Table 3.

Perioperative outcomes stratified by BMI categories

	Severely underweight	Underweight	Normal weight	Overweight	Obese	p
Operative mortality	1.6% (27)	0.9% (12)	0.9% (82)	0.9% (25)	1.2% (34)	0.04
Cardiopulmonary bypass time (minutes)	105 (IQR: 66–170)	100 (IQR: 63–158)	96 (IQR: 62–147)	101 (IQR: 67–159)	104 (IQR: 69–164)	<0.0001
Operating room time (hours)	5.9 (IQR: 4.2–7.7)	5.6 (IQR: 4.2–7.4)	5.4 (IQR: 4.1–7.1)	5.7 (IQR: 4.3–7.4)	6.0 (IQR: 4.5–7.9)	<0.0001
Length of stay (days)	5.0 (IQR: 3.0–8.0)	5.0 (IQR: 3.0–7.0)	4.0 (IQR: 3.0–6.0)	4.0 (IQR: 3.0–6.0)	5.0 (IQR: 4.0–7.0)	<0.0001
Major complication	9.4% (159)	7.1% (96)	5.9% (564)	5.9% (165)	6.4% (182)	<0.0001
Arrhythmia requiring pacemaker	2.1% (32)	1.5% (18)	1.6% (136)	1.4% (35)	1.7% (44)	0.51
New mechanical circulatory support	1.4% (21)	0.7% (8)	0.7% (64)	0.8% (21)	1.1% (29)	0.07
Renal failure requiring permanent dialysis	0.4% (6)	0.1% (1)	0.3% (22)	0.2% (5)	0.3% (8)	0.53
Renal failure requiring temporary dialysis	0.2% (5)	0.3% (4)	0.4% (30)	0.3% (8)	0.5% (12)	0.91
Neurological deficit at discharge	1.1% (17)	0.8% (10)	0.5% (44)	0.5% (12)	0.7% (17)	0.05
Phrenic nerve injury or diaphragm hemiparesis	0.1% (1)	0.3% (4)	0.4% (30)	0.3% (8)	0.5% (12)	0.91
Reoperation for bleeding	3.4% (52)	2.6% (31)	2.1% (179)	2.0% (50)	1.6% (40)	0.002
Unplanned cardiac operation	2.9% (49	1.6% (22)	1.4% (132)	1.5% (43)	1.9% (54)	0.0002
Unplanned interventional catheterization procedure	0.7% (12)	0.9% (12)	0.7% (63)	0.5% (13)	0.7% (19)	0.60
Unplanned non-cardiovascular procedure	1.5% (25)	1.3% (17)	0.8% (79)	0.9% (24)	0.6% (17)	0.02
Composite Outcome	17.4% (294)	14.1% (190)	10.6% (1021)	10.9% (305)	13.1% (375)	<0.0001
Wound infection or dehiscence	0.9% (16)	1.0% (14)	0.9% (85)	1.3% (36)	2.1% (61)	<0.0001
Prolonged length of stay	12.0% (203)	9.4% (127)	6.4% (614)	6.2% (174)	8.0% (229)	<0.0001

Abbreviations: IQR interquartile range