Is Administration of Preoperative Angiotensin-Converting Enzyme Inhibitors Important for Renal Protection after Cardiac Surgery?

Figures & data

Table 1. Preoperative patient characteristics among groups.

Variables	Treatment group (n = 186)	Control group (n = 180)	p-Value
Median age	59 ± 5.1	60 ± 5.5	0.870
Sex			0.910
Male	92 (49.4%)	89 (49.5%)
Female	94 (50.6%)	91 (50.5%)
Median weight (kg)	72 ± 3.1	69 ± 2.1	0.670
Diabetes mellitus	95 (51%)	42 (23.3%)	<0.05
COPD	77 (41.4%)	69 (38.3%)	0.338
Smoking	121 (65%)	118 (65.5%)	0.289
Hematocrit	44 ± 4	45 ± 5	0.777
Hypertension	138 (74.2%)	62 (34.4%)	<0.05
Preoperative IABP	21 (11.3%)	26 (14.4%)	0.144
Preoperative median GFR	156 ± 32	148 ± 34	0.766
PAD	41 (22%)	45 (25%)	0.190
History of MI	84 (45.1%)	81 (45%)	0.250
LVEF 0.40	45 (24.2%)	50 (27.7%)	0.870
BUN levels (mg/dL)	20 ± 7	21 ± 12	0.399
Creatinine levels (mg/dL)	1.1 ± 0.5	1.0 ± 0.6	0.557
CCL (mL/min)	52 ± 12	50 ± 14	0.902
Use of β-blockers	112 (60.2%)	55 (30.5%)	<0.05
Use of diuretics	49 (26.3%)	44 (24.4%)	0.221
Use of antiarrhythmic	21 (11.3%)	25 (13.9%)	0.233
Mean pulse rate (beats/min)	77 ± 14	80 ± 12	0.578
Mean BP (mm Hg)	97 ± 17	94 ± 18	0.103
Mean CVP (mm Hg)	10 ± 4	11 ± 5	0.911
Mean PAP (mm Hg)	20 ± 10	22 ± 11	0.907
Mean CI (L/min/m^2)	2.4 ± 0.6	2.3 ± 0.6	0.101

Notes: p-Values of <0.05 were considered significant. COPD, chronic obstructive pulmonary disease; GFR, glomerular filtration rate; IABP, intra-aortic balloon pump; LVEF, left ventricular ejection fraction; CI, cardiac index; PAP, pulmonary artery pressure; CVP, central venous pressure; BP, blood pressure; PAD, peripheral arterial disease; MI, myocardial infarction.

Table 2. Operative and postoperative data.

Data	Treatment group (n = 186)	Control group (n = 180)	p-Value
Only CABG	131 (70.4%)	129 (71.6%)	0.721
Only MVR	21 (11.3%)	16 (8.8%)	0.911
Only AVR	16 (8.6%)	13 (7.2%)	0.855
CABG + MVR	5 (2.7%)	7 (3.8%)	0.110
CABG + AVR	7 (3.7%)	6 (3.3%)	0.402
Aortic surgery	3 (1.6%)	5 (2.7%)	0.632
ASD	3 (1.6%)	4 (2.2%)	0.479
CC time (min)	58 ± 14	56 ± 12	0.303
CPB time (min)	35 ± 13	73 ± 13	<0.05
Operating time (h)	3.2 ± 1.8	5.3 ± 1.7	<0.05
Distal anastomoses	3 ± 1.2	3.1 ± 1.1	0.621
Postoperative IABP	7 (3.7%)	32 (17.7%)	<0.05
IMA usage	184 (99%)	179 (99.4%)	0.933
Use of inotropes	101 (54.3%)	111 (61.6%)	0.318
Use of trinitrates	16 (8.6%)	14 (7.7%)	0.402
Use of nipruss	6 (3.2%)	7 (3.8%)	0.430
Extubation time (h)	4.1 ± 2.1	3.1 ± 2.3	0.701
Postoperative BUN levels (mg/dL)	18 ± 11	41 ± 12	<0.05
Postoperative creatinine levels (mg/dL)	1.1 ± 0.8	2.1 ±1.4	<0.05
Postoperative CCL (mL/min)	41 ± 19	21 ± 14	<0.05
Postoperative median GFR	136 ± 22	88 ± 24	<0.05
Requiring dialysis	2 (1.1%)	24 (13.3%)	<0.05
ICU stay	3 ± 5	8 ± 4	<0.05
Hospital stay	7 ± 4	15 ± 3	<0.05
Operative mortality	6 (3.2%)	8 (4.4%)	0.127

Notes: p-Values of <0.05 were considered significant. CABG, coronary artery bypass grafting; MVR, mitral valve replacement; AVR, aortic valve replacement; ASD, atrial septal defect; CC, cross clamping; CPB, cardiopulmonary bypass; IMA, internal mammaria artery; BP, blood pressure; CVP, central venous pressure; PAP, pulmonary arterial pressure; CI, cardiac index; IABP, intra-aortic balloon pump; GFR, glomerular filtration rate; CCL, creatinine clearance; ICU, intensive care unit.

Table 3. Univariate logistic regression analysis (independent predictors for risk factors associated with renal dysfunction).

	Odds ratio	95% CI	p-Value
Median age	0.71	0.55–1.16	<0.05
Sex	4.66	2.01–9.62	0.521
Male
Female
Median weight (kg)	0.8	0.66–1.19	0.075
COPD	2.90	2.05–3.15	0.114
Smoking	2.5	1.26–5.18	0.870
PAD	1.19	1.01–1.33	0.521
History of MI	0.41	0.35–0.06	0.075
Hematocrit	3.79	2.41–6.88	0.101
Preoperative ACE inhibitors	0.71	0.55–1.16	<0.05
Preoperative LVEF <40	4.66	2.01–9.62	<0.05
Diabetes mellitus	2.90	2.05–3.15	<0.05
Hypertension	2.5	1.26–5.18	<0.05
Use of β-blockers	2.90	2.05–3.15	0.870
Use of diuretics	2.5	1.26–5.18	0.521
Use of antiarrhythmic	1.45	1.01–1.93	0.075
Mean BP (mm Hg)	1.45	0.17–12.14	0.075
Mean CVP (mm Hg)	0.86	0.61–1.30	0.114
Mean PAP (mm Hg)	0.77	0.81–2.80	0.870
Mean pulse rate (beats/min)	3.3	2.7–4.2	0.521
Mean CI (L/min/m^2)	2.7	2.3–3.1	0.521
Preoperative IABP	6.8	5.66–11.19	<0.05

Notes: p-Values of <0.05 were considered significant. ACE, angiotensin converting enzyme; CPB, cardiopulmonary bypass; CCL, creatinine clearance; ICU, intensive care unit; GFR, glomerular filtration rate; COPD, chronic obstructive pulmonary disease; PAD, peripheral arterial disease; IABP, intra-aortic balloon pump; LVEF, left ventricular ejection fraction; CI, cardiac index; PAP, pulmonary artery pressure; CVP, central venous pressure; BP, blood pressure.

Table 4. Multivariate logistic regression analysis for risk factors associated with renal dysfunction to receive angiotensin-converting enzyme inhibitor treatment preoperatively.

	Odds ratio	95% CI	p-Value
Age	0.76	0.58–1.19	<0.05
Preoperative ACE inhibitors	1.07	0.45–2.50	<0.05
Preoperative LVEF 40	0.96	0.41–2.25	<0.05
Diabetes mellitus	1.45	0.17–12.1	<0.05
Hypertension	0.86	0.61–1.30	<0.05
Preoperative IABP	7.33	6.80–10.5	<0.05

Note: p-Values of <0.05 were considered significant.

Table 5. The clinical results after cardiac surgery.

	Treatment group (n = 186)	Control group (n = 180)	p-Value
Cardiac dysfunction	11 (5.9%)	16 (8.8%)	NS
Cardiac arrhythmia	32 (17.2%)	45 (25%)	NS
Pulmonary dysfunction	41 (22%)	50 (27.7%)	NS
GI dysfunction	5 (2.7%)	4 (2.2%)	NS
Hepatic dysfunction	4 (2.2%)	3 (1.6%)	NS
Neurological dysfunction	9 (4.8%)	12 (6.6%)	NS
Multiple organ dysfunction	2 (1.1%)	4 (2.2%)	NS
Nosocomial infection	32 (17.2%)	27 (15%)	NS
Urinary tract infection	9 (4.8%)	8 (4.4%)	NS
Mediastinal infection	3 (1.6%)	3 (1.6%)	NS
Pneumonia	14 (7.5%)	16 (5%)	NS
Time to extubation (h)	2.7 ± 1.3	2.9 ± 1.8	NS
Surgical revision for bleeding	11 (5.9%)	10 (5.5%)	NS
Postoperative bleeding >1000 mL	11 (5.9%)	12 (6.6%)	NS
Death	3.6 ± 9.0	3.5 ± 10.2	NS