Cardiol Res

Cardiology Research, ISSN 1923-2829 print, 1923-2837 online, Open Access

Article copyright, the authors; Journal compilation copyright, Cardiol Res and Elmer Press Inc

Journal website https://www.cardiologyres.org

Original Article

Volume 14, Number 5, October 2023, pages 396-402

The Value of Left Internal Mammary Artery Flow Velocity in Predicting the Prognosis of Patients After Coronary Artery Bypass Grafting

Figure 1. The LIMAV measured by preoperative transthoracic ultrasound and intraoperative MGF. (a) Preoperative LIMAV was 81.7 cm/s. (b) Intraoperative MGF was 19 mL/min. LIMAV: left internal mammary artery flow velocity; MGF: mean graft flow.

Figure 2. Compared with the use of MGF, MGF + LIMAV, combination of the MGF + LIMAV + LVEF resulted in a stronger predictive value (MGF vs. MGF + LIMAV + LVEF: P = 0.02). LIMAV: left internal mammary artery flow velocity; LVEF: left ventricular ejection fraction; MGF: mean graft flow.

**Table 1.** Preoperative Baseline Characteristics of CABG Patients (n = 104)
Variables	Mean ± SD or n (%)
AMI: acute myocardial infarction; PCI: percutaneous coronary intervention; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; Apo-A1: apolipoprotein A1; Apo-B: apolipoprotein B; LVEDD: left ventricular end-diastolic dimension; LVESD: left ventricular end-systolic dimension; EDV: end-diastolic volume; ESV: end-systolic volume; SV: stroke volume; EF: ejection fraction.
Age (years)	61.18 ± 8.86
Male (%)	81 (77.9)
Hypertension history, n (%)	60 (57.7)
History (years)	9.41 ± 9.44
Systolic blood pressure (mm Hg)	171.05 ± 19.85
Diastolic blood pressure (mm Hg)	100.13 ± 8.75
Diabetes mellitus, n (%)	33 (31.7)
History (years)	8.08 ± 6.77
AMI history, n (%)	9 (8.7)
PCI history, n (%)	7 (6.7)
AMI, n (%)	18 (17.3)
AMI complications
Ventricular wall tumor formation, n (%)	1 (1)
Papillary muscle insufficiency, n (%)	0
Ventricular septum perforation, n (%)	1 (1)
Cholesterol (mmol/L)	3.82 ± 1.22
Triglyceride (mmol/L)	1.51 ± 0.61
HDL-C (mmol/L)	0.91 ± 0.22
LDL-C (mmol/L)	2.31 ± 1.18
Apo-A1 (mmol/L)	1.12 ± 0.40
Apo-B (mmol/L)	0.79 ± 0.25
Glucose (mmol/L)	6.21 ± 2.76
Glycated hemoglobin (%)	6.39 ± 1.52
Echocardiography
LVEDD (mm)	52.36 ± 6.34
LVESD (mm)	35.92 ± 7.50
EDV (mL)	135.29 ± 40.69
ESV (mL)	58.24 ± 31.86
SV (mL)	77.87 ± 18.24
EF (%)	57.43 ± 10.59
Normal	77 (74.1)
Mild abnormal	17 (16.3)
Moderate abnormal	10 (9.6)

Table 1. Preoperative Baseline Characteristics of CABG Patients (n = 104)

Variables

Mean ± SD or n (%)

AMI: acute myocardial infarction; PCI: percutaneous coronary intervention; HDL-C: high-density lipoprotein cholesterol; LDL-C: low-density lipoprotein cholesterol; Apo-A1: apolipoprotein A1; Apo-B: apolipoprotein B; LVEDD: left ventricular end-diastolic dimension; LVESD: left ventricular end-systolic dimension; EDV: end-diastolic volume; ESV: end-systolic volume; SV: stroke volume; EF: ejection fraction.

Age (years)

61.18 ± 8.86

Male (%)

81 (77.9)

Hypertension history, n (%)

60 (57.7)

History (years)

9.41 ± 9.44

Systolic blood pressure (mm Hg)

171.05 ± 19.85

Diastolic blood pressure (mm Hg)

100.13 ± 8.75

Diabetes mellitus, n (%)

33 (31.7)

History (years)

8.08 ± 6.77

AMI history, n (%)

9 (8.7)

PCI history, n (%)

7 (6.7)

AMI, n (%)

18 (17.3)

AMI complications

Ventricular wall tumor formation, n (%)

1 (1)

Papillary muscle insufficiency, n (%)

Ventricular septum perforation, n (%)

1 (1)

Cholesterol (mmol/L)

3.82 ± 1.22

Triglyceride (mmol/L)

1.51 ± 0.61

HDL-C (mmol/L)

0.91 ± 0.22

LDL-C (mmol/L)

2.31 ± 1.18

Apo-A1 (mmol/L)

1.12 ± 0.40

Apo-B (mmol/L)

0.79 ± 0.25

Glucose (mmol/L)

6.21 ± 2.76

Glycated hemoglobin (%)

6.39 ± 1.52

Echocardiography

LVEDD (mm)

52.36 ± 6.34

LVESD (mm)

35.92 ± 7.50

EDV (mL)

135.29 ± 40.69

ESV (mL)

58.24 ± 31.86

SV (mL)

77.87 ± 18.24

EF (%)

57.43 ± 10.59

Normal

77 (74.1)

Mild abnormal

17 (16.3)

Moderate abnormal

10 (9.6)

**Table 2.** Preoperative and Intraoperative Characteristics of LIMA (n = 104)
Characteristics	Mean ± SD or n (%)
DIAG: diagonal branch of coronary artery; LAD: left anterior descending branch; LCX: left circumflex coronary artery; LIMA: left internal mammary artery; MGF: mean graft flow; PI: pulsatility index; RCA: right branch of coronary artery.
LIMA
Diameter (mm)	2.38 ± 0.38
Velocity (cm/s)	78.69 ± 18.81
Number of bridges (n)	3 (1 - 8)
Bridge section of LIMA (n, %)
LIMA-LAD	78 (75)
LIMA-DIAG-LAD	18 (17.2)
LIMA-DIAG	5 (4.8)
LIMA-LCX	1 (1)
LIMA-RCA	2 (2)
Extracorporeal circulation (yes, %)	20 (19.2)
MGF (mL/min)	22.37 ± 15.07
PI	2.61 ± 0.89
Postoperative hospital stay (days)	13.30 ± 7.42

Table 2. Preoperative and Intraoperative Characteristics of LIMA (n = 104)

Characteristics

Mean ± SD or n (%)

DIAG: diagonal branch of coronary artery; LAD: left anterior descending branch; LCX: left circumflex coronary artery; LIMA: left internal mammary artery; MGF: mean graft flow; PI: pulsatility index; RCA: right branch of coronary artery.

LIMA

Diameter (mm)

2.38 ± 0.38

Velocity (cm/s)

78.69 ± 18.81

Number of bridges (n)

3 (1 - 8)

Bridge section of LIMA (n, %)

LIMA-LAD

78 (75)

LIMA-DIAG-LAD

18 (17.2)

LIMA-DIAG

5 (4.8)

LIMA-LCX

1 (1)

LIMA-RCA

2 (2)

Extracorporeal circulation (yes, %)

20 (19.2)

MGF (mL/min)

22.37 ± 15.07

2.61 ± 0.89

Postoperative hospital stay (days)

13.30 ± 7.42

**Table 3.** Univariate and Multivariate Cox Regression Analysis for Association Between Death and Various Parameters
	HR	95% CI	P
CI: confidence interval; HR: hazard ratio; LIMAV: left internal mammary artery flow velocity; LVEF: left ventricular ejection fraction; MGF: mean graft flow.
Univariate analysis
LVEF (%)	0.929	0.868 - 0.994	0.034
LIMAV (cm/s)	0.946	0.901 - 0.992	0.023
MGF (mL/min)	0.793	0.648 - 0.970	0.024
Multivariable analysis
LVEF (%)	0.910	0.844 - 0.980	0.013
LIMAV (cm/s)	0.922	0.857 - 0.992	0.029
MGF (mL/min)	0.748	0.600 - 0.932	0.010

Table 3. Univariate and Multivariate Cox Regression Analysis for Association Between Death and Various Parameters

95% CI

CI: confidence interval; HR: hazard ratio; LIMAV: left internal mammary artery flow velocity; LVEF: left ventricular ejection fraction; MGF: mean graft flow.

Univariate analysis

LVEF (%)

0.929

0.868 - 0.994

0.034

LIMAV (cm/s)

0.946

0.901 - 0.992

0.023

MGF (mL/min)

0.793

0.648 - 0.970

0.024

Multivariable analysis

LVEF (%)

0.910

0.844 - 0.980

0.013

LIMAV (cm/s)

0.922

0.857 - 0.992

0.029

MGF (mL/min)

0.748

0.600 - 0.932

0.010

**Table 4.** Predictive Value for Variables When Used to Predict Death
Variables	Cut-off	AUC	P	Sensitivity	Specificity	PPV	NPV
AUC: area under the curve; LIMAV: left internal mammary artery flow velocity; LVEF: left ventricular ejection fraction; MGF: mean graft flow; NPV: negative predictive value; PPV: positive predictive value.
MGF (mL/min)	≤ 14	0.830	< 0.001	100	65.6	19.518	100
LIMAV (cm/s)	≤ 60	0.759	< 0.001	62.5	85.3	26.182	96.46
LVEF (%)	≤ 44	0.724	0.009	50	88.5	26.617	95.499
MGF + LIMAV	-	0.887	< 0.001	100	76.8	26.448	100
MGF + LIMAV + LVEF	-	0.929	< 0.001	100	81.1	30.623	100

Table 4. Predictive Value for Variables When Used to Predict Death

Variables

Cut-off

AUC

Sensitivity

Specificity

PPV

NPV

AUC: area under the curve; LIMAV: left internal mammary artery flow velocity; LVEF: left ventricular ejection fraction; MGF: mean graft flow; NPV: negative predictive value; PPV: positive predictive value.

MGF (mL/min)

≤ 14

0.830

< 0.001

100

65.6

19.518

100

LIMAV (cm/s)

≤ 60

0.759

< 0.001

62.5

85.3

26.182

96.46

LVEF (%)

≤ 44

0.724

0.009

88.5

26.617

95.499

MGF + LIMAV

0.887

< 0.001

100

76.8

26.448

100

MGF + LIMAV + LVEF

0.929

< 0.001

100

81.1

30.623

100