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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 2, March/April 2017
120
AFRICA
Results
Demographic characteristics and clinical features of the patients
with aortic dilatation who underwent CPB and isolated CABG
surgery are summarised in Table 1. No statistically significant
differences were found between the groups for demographic and
clinical characteristics (
p
>
0.05).
The mean number of grafts used in the CABG operation
was calculated for group 1 [3.6
±
0.9 (median: 4; range: 1–6)]
and group 2 [1.5
±
0.5; (median: 1; range: 1–2)]. A statistically
significant intergroup difference was found (
p
=
0.0001).
Mean aortic cross-clamping durations were 54.9
±
11.5 min
(median: 65.5, range: 23–76) in group 1 and 26.7
±
6.4 min
(median: 25, range: 18–35) in group 2. A statistically significant
intergroup difference was found between the groups (
p
=
0.0001).
Mean CPB durations were 82.8
±
14.3 min (median: 84,
range: 39–109) in group 1 and 46.7
±
6.3 min (median: 46, range:
35–58) in group 2 (
p
=
0.0001). Total mean intubation times were
5.6
±
1.9 hours (median: 5, range: 3–14) in group 1 and 5.5
±
1.2 hours (median: 5, range: 4–12) in group 2. Mean duration
of stay in the postoperative intensive care unit was 29.3
±
17.1
hours (median: 21, range: 17–88) in group 1 and 29.7
±
15.3
hours (median: 22, range: 17–71) in group 2, with no significant
intergroup differences (
p
=
0.53).
Mean hospital stay of the patients was 6.1
±
1.6 days (median:
5, range: 5–12) in group 1 and 5.8
±
1.1 days (median: 5, range:
5–9) in group 2 with no significant intergroup differences (
p
=
0.83). In group 1, 48 (42.2%) and in group 2, 35 (44.9%) patients
required transfusion of blood and blood products during the
postoperative period, with no statistically significant difference
between the groups (
p
=
0.70). The mean total amount of
postoperative drainage was 348
±
169 ml (median: 300, range:
150–1100) in group 1 and 335
±
125 ml (median: 300, range:
150–700) in group 2, with no statistically significant intergroup
difference (
p
=
0.93).
Changes in the aortic root and ascending aortic diameter over
three years and analysis of this change are shown in Table 2. No
statistically significant intergroup difference was seen at the level
of the aortic annulus (Fig. 1) (
p
=
0.22,
p
=
0.25 and
p
=
0.13,
respectively). Annual changes in aortic diameter were found to
be extremely significantly different in both groups (
p
=
0.0001).
However, when mean differences in diameters were analysed
by year, no statistically significant intergroup difference was
detected (
p
=
0.21 and
p
=
0.37, respectively).
Mean values of aortic diameter at the level of the sinus of
Valsalva were not significantly different between the groups (Fig.
2) (
p
=
0.53,
p
=
0.37 and
p
=
0.30, respectively). However, annual
increases in diameter were found to be extremely significantly
different in both groups (
p
=
0.0001 and
p
=
0.0001, respectively).
The mean difference in diameter one year postoperatively
Table 1. Demographic and clinical characteristics of the patients
Group 1
(
n
=
114)
Presence of proxi-
mal anastomosis
Group 2
(
n
=
78)
Absence of proxi-
mal anastomosis
p
-value
Mean age (years)
(median, range)
63.0
±
9.2
(63, 42–80)
61.0
±
9.3
(61, 42–80)
0.12**
Male,
n
(%)
93 (60.4)
61 (39.6)
0.56*
Female,
n
(%)
21 (55.3)
17 (44.7)
0.45*
Ejection fraction (%)
(median, range)
53.5
±
10.2
(55, 30–70)
53.7
±
10.5
(55, 30–70)
0.91**
Hypertension,
n
(%)
28 (24.6)
27 (34.6)
0.13*
Diabetes mellitus,
n
(%)
43 (37.7)
37 (47.4)
0.18*
Smoking status,
n
(%)
34 (29.8)
19 (24.4)
0.41*
Hyperlipidemia,
n
(%)
44 (38.6)
34 (43.6)
0.49*
COPD,
n
(%)
11 (9.6)
5 (6.4)
0.43*
Pre-operative CRF,
n
(%)
6 (3.3)
2 (2.6)
0.48***
Peripheral artery disease,
n
(%)
8 (7.0)
3 (3.8)
0.53***
History of stroke,
n
(%)
7 (6.1)
2 (2.6)
0.32***
Previous myocardial infarction,
n
(%)
30 (26.3)
23 (29.5)
0.63*
Alcohol use,
n
(%)
15 (13.2)
8 (8.3)
0.54*
*Pearson’s chi-squared test; **Mann–Whitney
U
-test; ***Fisher’s exact test.
COPD
=
chronic obstructive pulmonary disease; CRF
=
chronic renal failure.
Table 2. Comparison of transthoracic echocardiography
measurements and annual differences
Group 1
(
n
=
114)
Presence of
proximal
anastomosis
Group 2
(
n
=
78)
Absence of
proximal
anastomosis
p
-value
Pre-operative annulus diameter
(mm) (median, range)
24.2
±
2.8
(24, 19–29)
23.7
±
3.1
(24, 18–31)
0.22
a
1st year annulus diameter (mm)
(median, range)
24.6
±
2.7
(25, 20–30)
24.2
±
2.9
(24, 19–31)
0.25
a
3rd year annulus diameter (mm)
(median, range)
25.6
±
2.8
(26, 21–31)
25.0
±
2.8
(25, 20–32)
0.13
a
p-v
alue
0.0001
b
0.0001
b
1st year annulus diameter difference
(mm) (median, range)
0.37
±
0.50
(0, 0–2)
0.46
±
0.53
(0, 0–2)
0.21
a
3rd year annulus diameter difference
(mm) (median, range)
1.37
±
0.55
(1, 1–3)
1.27
±
0.70
(1, 0–3)
0.37
a
p-v
alue
0.0001
b
0.0001
b
Pre-operative sinus of Valsalva
diameter (mm) (median, range)
37.2
±
1.6
(37, 34–40)
37.1
±
1.6
(37, 34–41)
0.53
a
1st year sinus valsalva diameter
(mm) (median, range)
38.0
±
1.7
(38, 35–41)
37.8
±
1.6
(38, 35–42)
0.37
a
3rd year sinus of Valsalva diameter
(mm) (median, range)
38.8
±
1.6
(39, 36–42)
38.5
±
1.7
(39, 35–42)
0.30
a
p-v
alue
0.0001
b
0.0001
b
1st year sinus of Valsalva diameter
difference (mm) (median, range)
0.79
±
0.43
(1, 0–2)
0.76
±
0.49
(1, 0–2)
0.57
a
3rd year sinus of Valsalva diameter
difference (mm) (median, range)
1.63
±
0.49
(2, 1–2)
1.45
±
0.53
(1, 1–3)
0.01
a
p-v
alue
0.0001
b
0.0001
b
Pre-operative STJ diameter (mm)
(median, range)
39.1
±
1.1
(39, 33–41)
38.9
±
1.6
(39, 36–42)
0.08
a
1st year STJ diameter (mm) (medi-
an, range)
40.3
±
1.1
(40, 37–42)
39.7
±
1.6
(39.5, 36–43)
0.002
a
3rd year STJ diameter (mm) (medi-
an, range)
41.4
±
1.2
(41.5, 38–44)
40.3
±
1.7
(40, 37–45)
0.0001
a
p-v
alue
0.0001
b
0.0001
b
1st year STJ diameter difference
(mm) (median, range)
0.99
±
0.36
(1, 0–2)
0.76
±
0.49
(1, 0–2)
0.0001
a
3rd year STJ diameter difference
(mm) (median, range)
2.21
±
0.66
(2, 0–3)
1.35
±
0.88
(1, 0–3)
0.0001
a
p-v
alue
0.0001
b
0.0001
b
Pre-operative ascending aorta diam-
eter (mm) (median, range)
41.5
±
1.3
(41, 40–45)
41.6
±
1.6
(41, 40–45)
0.79
a
1st year ascending aorta diameter
(mm) (median, range)
43.0
±
1.5
(43, 40–48)
42.1
±
1.5
(42, 40–45)
0.0001
a
3rd year ascending aorta diameter
(mm) (median, range)
44.3
±
1.6
(44, 42–49)
42.9
±
1.6
(43, 40–46)
0.0001
a
p-v
alue
0.0001
b
0.0001
b
1st year ascending aorta diameter
difference (mm) (median, range)
1.51
±
0.76
(2, 0–3)
0.58
±
0.57
(1, 0–2)
0.0001
a
3rd year ascending aorta diameter
difference (mm) (median, range)
2.77
±
0.95
(3, 1–5)
1.32
±
0.57
(1, 0–3)
0.0001
a
p-v
alue
0.0001
b
0.0001
b
a
Mann–Whitney
U
-test;
b
Friedman
S
-test; STJ
=
sinotubular junction.