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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
156
AFRICA
One hundred and thirty-eight of the patients were male, and the
mean age was 62.7
±
9.9 years. The demographic characteristics
of the patients are summarised in Table 1.
All of the patients were operated on with standard
cardiopulmonary bypass under general anaesthesia. Antegrade
cardioplegia was used for cardiac protection. In all cases, an
IABP catheter was inserted through the common femoral artery.
In this study, IABP was used intra-operatively when weaning
from cardiopulmonary bypass had failed. Pre-operative IABP
was used in cases of low cardiac output, unstable refractory
angina, or persistent arrhythmia due to myocardial ischaemia.
5,10
The patients were classified according to age; whether they
were younger than 65 years or older. The mortality rate,
complications of IABP, intra-operative properties, pre-operative
clinical characteristics of patients, and length of stay in the
intensive care unit were recorded.
The pre-operative parameters of the patients were age,
gender, re-operation, hypertension, body mass index, diabetes
mellitus, chronic renal failure, EuroSCORE value, previous
cerebrovascular accident, left ventricular ejection fraction, left
main coronary artery disease, chronic obstructive pulmonary
disease (COPD), and the presence of a myocardial infarction
more recent than one week earlier. The pre-operative clinical
characteristics, postoperative complications, duration of ICU and
hospital stays, and mortality rates of the groups were compared.
Statistical analysis
Demographic characteristics were compared with mean and
median values. Parametric results were evaluated using a
Student’s
t
-test and Tukey test. A chi-square method, Pearson’s
test, and Fisher’s test were used to analyse the categorical
parameters. Risk factors for mortality were assessed using a
binary logistic regression analysis. The standard deviation value
p
<
0.05 was considered significant. SPSS 18 was used for the
statistical analysis.
Results
In this study, 138 of the 190 patients were male. The mean patient
age was 62.7
±
9.9 years. Ninety-eight patients were younger than
65 years of age, and 90 patients were 65 years of age or older.
The number of patients with chronic obstructive pulmonary
disease and the mean EuroSCORE value of the patients were
higher in the older group. By contrast, the number of patients
with diabetes mellitus was higher in the younger group. In terms
of other demographic characteristics, there were no statistically
significant differences between the groups (Table 1). The mean
cardiopulmonary bypass times, mean cross-clamp times, and
number of grafts used were similar between the two groups
(Table 2).
Fifty-seven (30.1%) patients died in the first 30 days following
the operation. Twenty-three of these patients were in the younger
group. The mortality rate of the younger group was significantly
Table 1. Demographic characteristics of the patients
Younger
group
(n
=
98)
Older
group
(n
=
92) Total
p-value
Male/female
74/24
64/28 138/52 0.358
Mean age
54.7
±
6.1 71.4
±
4.5 62.7
±
9.9
<
0.001
Mean EF
37.1
±
8.3 39.2
±
9.5 38.1
±
8.9 0.121
MI,
n
(%)
31 (31.9) 24 (26) 55 (27.7)
0.400
COPD,
n
(%)
5 (5.1) 13 (14.1)
18 (9)
0.034
CRF,
n
(%)
3 (3)
5 (5.4)
8 (4.2)
0.487
Redo,
n
(%)
3 (3)
0
3 (1.5)
0.297
HT,
n
(%)
47 (48)
56 (60) 103 (54)
0.074
DM,
n
(%)
48 (49)
23 (25) 71 (37.3)
0.001
CVA,
n
(%)
4 (4.1)
5 (5.4)
9 (4.7)
0.745
Recent MI,
n
(%)
18 (18.3) 16 (17.4) 34 (17.9)
0.861
EuroSCORE
4 (0–10) 5 (2–10) 4 (0–10)
<
0.001
BMI
27.2
±
4 26.7
±
4.4 27.2
±
4.1 0.112
LMCA
8 (8.1)
5 (5.4)
13 (6.8)
0.457
Prophylactic levosimendan 18 (18.3) 12 (13) 30 (15.8)
0.315
Emergency
18 (18.3) 16 (17.4) 34 (17.8)
0.861
Pre-operative IABP
8 (8.1)
9 (9.7)
17
0.405
COPD: chronic obstructive pulmonary disease, CRF: chronic renal
failure, HT: hypertension, DM: diabetes mellitus, CVA: cerebrovas-
cular accident, MI: myocardial infarction, BMI: body mass index,
LMCA: left main coronary artery disease, EF: ejection fraction.
Table 2. Mortality rates and clinical outcomes of the patients
Younger group
(n
=
98)
Older group
(n
=
92)
p-value
Mortality
23 (23.4)
34 (36.9)
0.043
Mortality*
8 (44.4)
7 (41.1 %)
0.964
Mortality**
15 (18.7)
27 (36%)
0.018
CPB time (min)
143
±
59
140
±
58
0.786
Graft number
3.1 (2–5)
3.2 (2–5)
0.789
Cross clamp time (min)
90
±
34
88
±
38
0.604
ICU time (days)
5.9
±
4
6.6
±
5
0.284
ICU: intensive care unit, CPB time: cardiopulmonary bypass time,
*patients undergoing emergency operations, **patients undergoing
elective operations.
Table 3. Risk factors in patients who survived or died
Patients survived
(n
=
133)
Patients died
(n
=
57) p-value
Pre-operative MI,
n
(%)
40 (30)
15 (26.3)
0.601
BMI
27.5
±
4.2
26.9
±
4
0.507
EuroSCORE
4.2 (0-10)
5.1 (0-10)
0.030
DM,
n
(%)
47 (35.3)
24 (42.1)
0.377
CRF,
n
(%)
3 (2.2)
5 (8.7)
0.040
Mean EF %
38.4
±
8
37.5
±
9
0.562
Mean age (year)
61.8
±
9.8
64.9
±
10
0.051
Older patients,
n
(%)
58 (43.6)
34 (59.6)
0.043
Gender (female/male)
33/101
20/37
0.118
COPD,
n
(%)
12 (9)
6 (10.5)
0.746
Emergency operation,
n
(%)
19 (14.2)
15 (26.3)
0.047
LMCA,
n
(%)
8 (6)
5 (8.7)
0.490
CVA,
n
(%)
5 (3.7)
4 (7)
0.333
HT,
n
(%)
69 (51.8)
34 (59.6)
0.328
Re-operation,
n
(%)
3 (2.2)
0
0.555
Pre-operative IABP,
n
(%)
14 (10.5)
3 (2.2)
0.405
CPB time (min)
130
±
48
167
±
72
<
0.001
Cross-clamp time (min)
87
±
35
94
±
36
0.180
CPB time: cardiopulmonary bypass time. COPD: chronic obstructive
pulmonary disease. CRF: chronic renal failure. HT: hypertension.
DM: diabetes mellitus. CVA: previous cerebrovascular accident. BMI:
body mass index. LMCA: left main coronary artery disease.