CARDIOVASCULAR JOURNAL OF AFRICA • Vol 22, No 4, July/August 2011
184
AFRICA
early after PCI. Previous studies have shown different results
regarding systolic functional improvement following PCI. In
a study performed in 41 patients with stable CAD, successful
elective PCI did not improve ejection fraction at the one-day and
six-month follow up.
5
However, in another study, peak systolic velocities of three
annular sites, but not the ejection fraction, showed substantial
improvement.
6
It was also shown in 32 patients that resting EF
and WMSI improved significantly after three to five days and
six months, following successful elective PCI.
7
In addition, the
index of myocardial performance (Tei index), which reflects both
systolic and diastolic myocardial performance, did not improve
in our study.
It is postulated that patients with severely depressed ventricu-
lar dysfunction (LVEF
<
40%) benefit most from revascularisa-
tion.
15
Therefore the possible explanation for these findings could
be the fact that the patients included in our study had LVEF
>
40% at baseline and therefore experienced little improvement.
Among various echo-technique parameters assessing diastolic
function, only colour M-mode Vp was found to have improved
significantly 48 hours after PCI. There have been various reports
on improvements observed in diastolic parameters following
PCI. Diller
et al
.
16
analysed the results of successful elective PCI,
using TDI before PCI as well as one day and six weeks after the
procedure, on systolic and diastolic function in 24 consecutive
patients with CAD and normal systolic function. They found
that all tissue Doppler measurements of early diastolic func-
tion improved significantly after PCI, and systolic peak veloc-
ity improved in the septal, lateral, inferior and right ventricular
areas.
16
A study performed on 31 patients with chronic CAD showed
that most echocardiographic diastolic indices, including IVRT,
EDT, E/A ratio, IVCT and diastolic indices of both the mitral
and tricuspid annulus sites on TDI improved significantly 24
hours following elective PCI.
6
In another study, LV diastolic
filling improved marginally within 10 days of PCI and persisted
up to 30 days.
8
By contrast, in a study in 15 patients with single
anterior descending coronary artery stenosis and normal systolic
function, abnormalities in early and late LV filling velocities
lasted as long as three months after PCI.
9
There is evidence that abnormalities in diastolic function may
precede systolic dysfunction during myocardial ischaemia.
17
It
has been shown that early LV diastolic function becomes severe-
ly impaired during ischaemia.
18
The early ventricular relaxation
is a highly energy-dependent process.
19
Therefore, the restora-
tion of blood flow following PCI might affect diastolic function
earlier than systolic function.
Vp, which was initially proposed by Brun
et al
.
20
as a sensitive
non-invasive indicator of impaired diastolic relaxation, repre-
sents the rate of change in velocity of blood flow in early diastole
and indicates the time difference between maximal velocity at
the apex level and the mitral leaflet tips. It is a unique measure
for accurate and reliable assessment of ventricular relaxation,
since it is independent of preload.
21
The reason for persistence of abnormal indices of LV perfor-
mance (other than Vp) may be the duration of disease before
PCI.
22
These indices may have been improved if patients had
undergone PCI earlier during the course of their disease. Hence
we say ‘time is muscle’. However, it is believed, based on the
‘open artery theory’, that even late reperfusion provides benefi-
TABLE 2. EARLY ECHOCARDIOGRAPHIC INDICES
OFVENTRICULAR SYSTOLIC FUNCTION
BEFOREANDAFTER SUCCESSFUL PCI IN
21 PATIENTSWITH STABLE CAD*
Method
Index
Pre-PCI
Post-PCI
p
-value
2-D echocardiography
LVEF (%)
47
±
7.7 48.4
±
9.2 0.10
WMSI
1.41
±
0.35 1.39
±
0.39 0.26
M-mode echocardiography
TAPSE (mm)
23
±
2.7 23.2
±
3.2 0.64
Doppler echocardiography
Tei index
0.4
±
1.1 0.4
±
1.1 0.33
Tissue Doppler Imaging (cm/sec)
Sa – septal
7.10
±
1.37 7.29
±
1.42 0.58
Sa – lateral
8.52
±
2.25 8.19
±
2.36 0.44
Sa – inferior 8.38
±
1.91 8
±
1.30 0.29
Sa – anterior 7.48
±
2.14 7.2
±
1.47 0.46
Sa – posterior 8.19
±
1.72 8.24
±
1.58 0.92
TA-Sa
11.8
±
2 12.2
±
2
0.282
*Means
±
standard deviation. PCI: percutaneous coronary interven-
tion; CAD: coronary artery disease; LVEF: left ventricular ejection
fraction; WMSI: wall motion abnormality score index; Sa: peak
systolic velocity of mitral annulus; TA-Sa: peak systolic velocity of
tricuspid annulus.
TABLE 3. EARLY ECHOCARDIOGRAPHIC INDICES
OFVENTRICULAR DIASTOLIC FUNCTION
BEFOREANDAFTER SUCCESSFUL PCI IN
21 PATIENTSWITH STABLE CAD*
Method
Index
Pre-PCI
Post-PCI
p
-value
Doppler echocardiography
E (m/s)
0.7
±
0.2 0.7
±
0.2 0.52
A (m/s)
0.7
±
0.2 0.7
±
0.2 0.83
E/A
1
±
0.4 0.9
±
0.2 0.27
DT (m sec)
214.1
±
50 204.7
±
57.8 0.48
IVRT (m sec)
93.6
±
18.7 96.3
±
18.5 0.53
Vp (cm/sec)
42.9
±
10.8 51.8
±
10.7 0.008
PVs (cm/sec)
55.2
±
11 56.9
±
11.7 0.41
PVd (cm/sec)
44
±
10.4 42
±
2.3 0.46
Tissue Doppler imaging (cm/sec)
Septal
Ea
6.6
±
1.7 7.3
±
2.2 0.08
Aa 8.8
±
1.7 8.8
±
1.7 1.00
Lateral
Ea
9
±
2.8 8.5
±
2.6 0.29
Aa 8.2
±
2.4 8.4
±
1.9 0.79
Inferior Em 7.6
±
2.9
7
±
1.5 0.32
Aa 7.6
±
1.5 7.8
±
2.1 0.72
Anterior Ea
8
±
2.8 7.3
±
2.6 0.14
Aa
10
±
2.4 9.8
±
2
0.75
Posterior Ea
8.5
±
3.1 8.5
±
2.8 0.94
Aa 9.4
±
3.3 8.2
±
2.3 0.08
*Means
±
standard deviation. TAPSE: tricuspid annular plane systolic
excursion; E: peak early diastolic velocity; A: peak late diastolic
velocity; DT: deceleration time; IVRT: isovolumic relaxation time;
Vp: mitral inflow propagation velocity; PVs: pulmonary vein systolic
flow velocity; PVd: pulmonary vein diastolic flow velocity; Ea: early
diastolic velocitiy of mitral annulus; Aa: late diastolic velocitiy of
mitral annulus.
