Correlation Between Cardiac Index, Plasma Troponin I, Myocardial Histopathology, CPB and AoX Duration in Glutamine versus No Glutamine Administered Patients with Low Ejection Fraction Undergoing Elective On-Pump CABG Surgery: Secondary Analysis of an RCT

Figures & data

Table 1 Patient Characteristics

Parameters	Glutamine (n = 29)	Control (n = 29)	p-value
Age, years	60 ± 7	61 ± 6	0.545
Gender, male/female	26 / 3	28 / 1	0.611
BMI, kg/m^2	26.25 ± 2.53	26.47 ± 2.85	0.753
Preoperative ejection fraction, %	41 (31–50)	44 (31–49)	0.349
Coronary grafts	3 (2–4)	3 (2–4)	0.606
Duration of surgery, minutes	226 ± 46	214 ± 50	0.373
CPB time, minutes	87 (55–113)	78 (39–138)	0.630
AoX time, minutes	44 ± 9	44 ± 15	0.873

Note: Values are presented as mean ± standard deviation or median (range).

Abbreviations: AoX, aortic cross-clamping; BMI, body mass index; CPB, cardiopulmonary bypass.

Table 2 Plasma Troponin I Level and Cardiac Index Between Control and Glutamine Group

Measurement Time After CPB	Plasma Troponin I (ng/mL)			Cardiac Index (L/min/m^2)
	Glutamine (n = 29)	Control (n = 29)	p-value	Glutamine (n = 29)	Control (n = 29)	p-value
5 minutes	1.66 (0.00–4.07)	1.70 (0.00–4.61)	0.883	3.15 ± 0.57	3.03 ± 0.38	0.352
6 hours	3.07 (1.49–7.93)	4.31 (1.62–9.25)	0.034*	2.54 ± 0.45	2.27 ± 0.40	0.022*
24 hours	3.08 (1.30–6.59)	3.77 (0.00–36.53)	0.038*	2.68 ± 0.35	2.47 ± 0.41	0.038*
48 hours	1.66 (0.00–7.33)	1.75 (0.00–53.33)	0.423	-	-	-

Notes: Values are presented as mean ± standard deviation or median (range). Statistical significance (p < 0.05) is marked with *.

Abbreviation: CPB, cardiopulmonary bypass.

Table 3 Histopathologic Examinations of the Right Atrial Appendage Tissue Between Control and Glutamine Group

Histopathologic Examinations	Glutamine (n = 29)	Control (n = 29)	p-value
Myocardial injury score	1.33 (1.00–2.00)	1.42 (1.00–2.00)	0.011*
Apoptotic index	5.00 (0.00–45.00)	6.17 (1.00–52.00)	0.975
Anti-cardiac troponin I expression	–0.33 (–1.00–0.00)	–0.83 (–1.00–0.00)	0.031*

Notes: Values are presented as median (range). Statistical significance (p < 0.05) is marked with *.

Table 4 Correlation Between Plasma Troponin I Level and Histopathological Examinations at 5 Minutes After CPB

Histopathologic Examinations	Plasma Troponin I Level
	Glutamine (n = 29)		Control (n = 29)
Myocardial injury score	p = 0.135	r = 0.284	p = 0.298	r = −0.200
Apoptotic index	p = 0.573	r = 0.109	p = 0.220	r = 0.235
Anti-cardiac troponin I expression	p = 0.807	r = −0.047	p = 0.094	r = 0.317

Abbreviation: CPB, cardiopulmonary bypass.

Table 5 Correlation Between Cardiac Index, AoX and CPB Duration

Measurement Time of CI After CPB	Glutamine (n = 29)		Control (n = 29)
	AoX Duration	CPB Duration	AoX Duration	CPB Duration
5 minutes	p = 0.513	p = 0.614	p = 0.129	p = 0.161
	r = −0.127	r = 0.098	r = −0.289	r = −0.268
6 hours	p = 0.239	p = 0.037*	p = 0.958	p = 0.410
	r = −0.226	r = −0.390	r = 0.010	r = −0.159
24 hours	p = 0.054	p = 0.436	p = 0.851	p = 0.473
	r = −0.362	r = −0.151	r = 0.036	r = −0.139

Note: Statistical significance (p < 0.05) is marked with *.

Abbreviations: AoX, aortic cross-clamping; CI, cardiac index; CPB, cardiopulmonary bypass.

Table 6 Correlation Between Plasma Troponin I Level, AoX and CPB Duration

Measurement Time of Plasma Troponin I Levels After CPB	Glutamine (n = 29)		Control (n = 29)
	AoX Duration	CPB Duration	AoX Duration	CPB Duration
5 minutes	p = 0.097	p = 0.001*	p = 0.118	p = 0.005*
	r = 0.314	r = 0.569	r = 0.297	r = 0.503
6 hours	p = 0.062	p = 0.019*	p = 0.002*	p = 0.018*
	r = 0.351	r = 0.433	r = 0.548	r = 0.437
24 hours	p = 0.276	p = 0.259	p = 0.186	p = 0.320
	r = 0.209	r = 0.217	r = 0.253	r = 0.191
48 hours	p = 0.793	p = 0.826	p = 0.506	p = 0.573
	r = 0.051	r = 0.043	r = 0.129	r = −0.109

Note: Statistical significance (p < 0.05) is marked with *.

Abbreviations: AoX, aortic cross-clamping; CPB, cardiopulmonary bypass.