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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015
AFRICA
157
lower compared with the older patients (
p
=
0.043). In the
subgroup analysis, the mortality rate of emergent operations was
similar in the younger and older groups (
p
=
0.964). However,
the mortality rate was higher in the older group for elective
operations (
p
=
0.018).
Among the surviving patients, the number of older patients,
rate of emergency operations, mean EuroSCORE values, and
number of patients with chronic renal failure were lower than
in the group of patients who died (Table 3). Binary logistic
regression analysis showed that the only factor affecting mortality
was prolonged cardiopulmonary bypass time. However, in the
subgroup analysis of patients without emergency conditions, age
was the second determinant of mortality (
p
=
0.018, OR
=
5.5).
In the subgroup analysis, cardiopulmonary bypass time
and pre-operative chronic renal failure were independent risk
factors for mortality in the older group. In the younger group,
female gender, diabetes mellitus, high EuroSCORE, emergency
operation, prolonged cardiopulmonary bypass time (
p
=
0.001,
OR
=
7.6), and prolonged stay in the intensive care unit were
independent risk factors for mortality (Table 4).
In our study, a few serious complications were observed due
to IABP support. Iliac artery injury occurred in two patients and
peripheral ischaemia was observed in three patients. The other
complications were thrombocytopaenia and minor bleeding at
the catheter site (Table 5). The rate of complications was similar
between the groups.
Discussion
Postoperative recovery in elderly patients takes a longer time
than in younger patients. Postoperative atrial fibrillation
requiring medical treatment, and other complications occur more
frequently in the elderly; the total intubation time is also longer
for this group. Therefore, delayed recovery in the elderly may
simply be due to the aging process affecting all organs.
9
For this
reason, elderly patients may need more mechanical support in
cases of low cardiac output following cardiopulmonary bypass.
In the present study, while the number of COPD patients
was higher in the older group, the number of diabetes mellitus
patients was lower in the older group. In addition, EuroSCORE
values were higher in the elderly patients. The mortality rate was
higher in elderly patients; however, there were no statistically
significant differences between the patients who had emergency
surgery in both groups.
It has been reported that IABP decreases the mortality
rates of low-cardiac output and severe myocardial ischaemia
patients in the pre-operative period, provides support for patients
who failed to wean from cardiopulmonary bypass during the
intra-operative period, and prevents low cardiac output and
medically refractory arrhythmias in intensive care units in the
postoperative period.
11,12
In this study, IABP was used in cases of
low cardiac output, persistent angina pectoris, or arrhythmia due
to myocardial ischaemia in the pre-operative period.
In previous studies, the use of pre-operative IABP in high-risk
patients was reportedly more advantageous than peri-operative
IABP support. Böning
et al
. compared the use of pre-operative
and peri-operative IABP in high-risk patients in their study.
Their results indicate that the pre-operative use of IABP was
advantageous for early and long-term mortality.
13
Dyub
et al.
showed that in a meta-analysis involving 1 034 patients, the use
of pre-operative IABP in high-risk patients reduced mortality
rates.
14
Holman
et al
. reported that when shock, urgent surgery,
haemodynamic instability, and MI in the last three days were
excluded, the use of pre-operative IABP did not have a positive
effect on morbidity and mortality rates; however, the length of
the hospital stay was shorter in these patients.
15
Miceli
et al
. proposed a scoring system that predicts the need
for IABP support in high-risk coronary artery bypass patients.
16
According to this study, heart failure, re-operation, emergency
operation, left main coronary artery disease, patients over the
age of 70 years, moderate and poor left ventricular function, and
recent myocardial infarctions are independent risk factors for the
need for IABP support. As a result of the study, the benefits of
IABP support in patients with high-risk scores were emphasised.
In our clinical practice, we did not use a risk-scoring system for
prophylactic IABP support. In this study, we aimed to determine
the pre-operative risk factors for mortality and other clinical
outcomes.
In previous studies, emergency surgery, a history of myocardial
infarction, prolonged cardiopulmonary bypass, and concomitant
peripheral artery occlusive disease were all found to be significant
determinants of mortality in primary isolated CABG patients.
17
Furthermore, risk-scoring systems were generated. We showed
Table 4. Risk factors for mortality in subgroup analysis
Younger group
Older group
OR p-value OR p-value
COPD
0.035 0.851 0.015 0.903
CRF
0.168 0.682 4.205 0.040
Re-operation
0.949 0.330
–
–
EF (%)
0.865 0.352 0.110 0.759
Age (year)
0.122 0.727 1.034 0.741
EuroSCORE
14.555 0.000 8.418 0.309
CPB time (min)
7.698 0.006 0.471 0.004
Cross-clamp time (min)
2.048 0.152 1.542 0.493
BMI
0.703 0.402 0.384 0.214
Emergency operation
5.401 0.020 0.400 0.536
Female gender
8.850 0.003 1.725 0.527
HT
2.007 0.157 0.095 0.189
MI
0.427 0.513 0.004 0.758
DM
7.477 0.006 0.560 0.949
ICU time
4.947 0.026 0.038 0.454
Levosimendan
0.228 0.633 0.131 0.845
CVA
1.634 0.201 0.021 0.717
LMCA
0.955 0.329 0.021 0.885
CPB time: cardiopulmonary bypass time. COPD: chronic obstruc-
tive pulmonary disease. CRF: chronic renal failure. HT: hyperten-
sion. DM: diabetes mellitus. ICU: intensive care unit. CVA: previous
cerebrovascular accident. BMI: body mass index. LMCA: left main
coronary artery disease.
Table 5. IABP complications according to patient groups
Younger
group
Older
group p-value
Bleeding,
n
(%)
1 (1)
4 (4.3)
0.200
Arterial injury,
n
(%)
0
2 (2.1)
0.233
Mild thrombocytopaenia,
n
(%)
10 (10.2)
15 (16.3)
0.309
Extremity ischaemia,
n
(%)
1 (1)
2 (2.1)
0.611
Total,
n
(%)
12 (12.2)
23 (25)
0.023