Bilateral vs unilateral internal mammary revascularization in patients with left ventricular dysfunction

Table 1 Clinical and demographic characteristics of the study groups

Characteristics [n (%)]	Unmatched groups			Propensity score-matched groups
	BIMA (n = 167)	LIMA-SVG (n = 263)	P	BIMA (n = 130)	LIMA-SVG (n = 130)	P
Age (yr)	58.5 ± 10.3	64.3 ± 9.0	0.01	60.6 ± 9.9	60.5 ± 10.0	0.95
Female sex	20 (12.0)	30 (11.5)	0.88	16 (12.3)	19 (14.6)	0.71
Hypertension	87 (52.4)	163 (61.5)	0.07	70 (53.8)	73 (56.2)	0.80
Diabetes mellitus	66 (39.5)	97 (36.9)	0.61	53 (40.8)	54 (41.5)	0.90
Hypercholesterolemia1	99 (59.6)	183 (69.6)	0.04	79 (60.8)	82 (63.1)	0.79
History of smoking	116 (69.5)	173 (65.8)	0.53	84 (64.6)	83 (63.8)	0.89
Body mass index (kg/m2)	27.6 ± 4.4	27.4 ± 4.3	0.85	27.6 ± 4.5	27.3 ± 4.3	0.56
Other comorbid conditions	16 (9.6)	31 (11.8)	0.53	12 (9.2)	9 (6.9)	0.65
Chronic renal insufficiency COPD2	28 (16.8)	53 (20.5)	0.38	24 (18.5)	23 (17.7)	0.87
Peripheral artery disease	55 (33.1)	111 (42.2)	0.07	44 (33.8)	45 (34.6)	0.89
Prior ischemic cardiopathy	83 (49.7)	154 (58.5)	0.11	68 (52.3)	67 (51.5)	0.90
Previous PCI	48 (28.7)	70 (26.6)	0.66	36 (28.5)	38 (29.2)	0.89
EuroSCORE logistic3 (%)	7.5 ± 6.9	8.0 ± 6.0	0.21	7.5 ± 7.1	8.0 ± 6.1	0.90
Symptoms
Stable angina pectoris	50 (30.1)	70 (26.6)	0.90	36 (28.5)	36 (27.7)	0.90
Acute coronary syndrome	71 (42.5)	117 (44.5)	0.86	58 (44.6)	55 (42.3)	0.90
ambulatory Q wave MI	22 (13.2)	40 (15.2)	0.95	18 (13.8)	21 (16.2)	0.85
silent ischemia	33 (13.8)	36 (13.7)	0.98	17 (13.1)	18 (13.8)	0.90
NYHA class 3-4	47 (28.1)	112 (42.8)	0.03	45 (34.6)	46 (35.4)	0.99
Angiographic parameters: Three coronary arteries narrowed (≥ 70%)	112 (67.1)	165 (62.7)	0.35	83 (63.8)	85 (65.4)	0.90
Mitral insufficiency grade ≥ 2	24 (14.6)	46 (18.0)	0.19	22 (16.9)	24 (18.5)	0.80
Left ventricular chamber dilatation	55 (32.9)	100 (38.0)	0.29	45 (34.6)	47 (36.1)	0.42
Ejection fraction (%)	35.2 ± 5.9	33.5 ± 5.8	0.58	34.5 ± 6.0	34.6 ± 5.6	0.80

¹Previously documented diagnosis of dyslipidemia or new diagnosis for a total cholesterol > 200 mg/dL;

²Creatinine clearance < 40 mL/min;

³EuroSCORE: European System for Cardiac Operative Risk Evaluation score. BIMA: Bilateral internal mammary artery; LIMA: Left internal mammary artery; SVG: Saphenous vein graft; COPD: Chronic obstructive pulmonary disease; PCI: Percutaneous coronary intervention; MI: Myocardial infarction; NYHA: New York Heart Association.

Table 2 Procedural characteristics of the study groups

Characteristics [n (%)]	BIMA group (n = 167)	LIMA-SVG group (n = 263)	P
On-pump surgery	164 (98.8)	245 (93.1)	0.80
Mean number of grafts per patient	2.5 ± 0.6	2.5 ± 0.7	0.91
Complete coronary revascularization	117 (70.1)	175 (66.5)	0.50
Extracorporeal circulation time (min) Median (IQR)	79.5 (65.2-100)	80.0 (64-100)	0.86
Length of stay in ICU (d) Median (IQR)	3.1 (2-4)	3.2 (2-5)	0.11
Length of stay in hospital (d) Median (IQR)	8.2 (7-11)	9.3 (6-12)	0.12
Ventilation time < 24 h	160 (95.8)	210 (79.9)	< 0.01
IABP	12 (7.2)	24 (9.1)	0.80
Vasopressors or inotropic drugs (> 24 h)	45 (27.3)	107 (41.1)	< 0.01
Transfusion (red blood cell units ≥ 3)	53 (31.7)	123 (46.7)	< 0.01

BIMA: Bilateral internal mammary artery; LIMA: Left internal mammary artery; SVG: Saphenous vein graft; ICU: Intensive care unit; IABP: Intra-aortic balloon counterpulsation.

Table 3 In-hospital course

Characteristics [n (%)]	BIMA group (n = 167)	LIMA-SVG group (n = 263)	P
All-cause mortality	13 (7.8)	27 (10.3)	0.49
Cardiovascular mortality	8 (4.8)	23 (8.7)	0.10
Myocardial infarction	7 (4.2)	10 (3.8)	0.80
Redo CABG	2 (1.2)	2 (0.8)	0.64
Stroke	2 (1.2)	10 (3.8)	0.14
Mesenteric ischemia	3 (1.8)	5 (1.9)	0.94
Mediastinitis	9 (5.3)	6 (2.3)	0.11
Cardiac rehabilitation	79 (47.3)	104 (39.5)	0.40
1-yr follow up LVEF	44.2% ± 10.1%	41.3% ± 10.2%	0.81

BIMA: Bilateral internal mammary artery; LIMA: Left internal mammary artery; SVG: Saphenous vein graft; CABG: Coronary artery bypass graft; LVEF: Left ventricular ejection fraction.