145 patients were selected for the study.
In physical examination before surgery,
few patients were asymptomatic,
while all others had a variety of symptoms: worsening exertional dyspnoea,
chronic non-productive cough,
atypical chest pain,
tachycardia,
syncope,
and cor pulmonale.
All patients had hemodynamic evidence of PH (mPAP values > 25 mmHg),
which was also confirmed by radiological evaluation through the presence of typical CT signs.
CTPA revealed the presence of unilateral disease only in 10 patients,
while 135 patients had bilateral disease.
106 patients showed a peripheral disease,
6 patients proximal disease and 33 patients a mixed-type (Fig.
1).
As concerns all the sample,
high significant statistical relationships were observed between our New CT Score and both mPAP and PVR (p<0.000).
mPAP also correlated with main Pulmonary Artery (p<0.01); a significant relationship was found between PVR both with tricuspid regurgitation (p<0.000) and presence of unilateral or bilateral pulmonary thromboembolic occlusion (p=0.06); in addition mPAP and PVR showed an important relationship with the severity of mosaic perfusion (p<0.000) in all 145 patients.
Finally we observed that bronchial artery hypertrophy did not show a significant relationship neither with mPAP nor PVR.
Statistical analysis of comparison between radiological and hemodynamic parameters is shown in Table 3.
|
Score
|
Mosaic-perfusion degree
|
PA diameter
|
Tricuspid Regurgitation
|
Unilateral/Bilateral disease
|
Bronchial artery hypertrophy
|
mPAP
|
p<0,000
|
p<0,000
|
p= 0,019
|
p>0.05
|
p>0.05
|
p>0.05
|
PVR
|
p<0,000
|
p<0,000
|
p>0.05
|
p<0,000
|
p=0.06
|
p>0.05
|
|
Table 3. Statistical relationships resulted from our analysis in all the sample (145 patients).
The second step of our study consisted in evaluating the group of patients who underwent surgery; we compared our New Score with mPAP and PVR before and after surgical intervention and we observed significant relationships as displayed in Table 4.
|
mPAP pre
|
PVR pre
|
mPAP post
|
PVR post
|
Score pre
|
p=0,005
|
p<0,000
|
|
|
Score post
|
|
|
p=0,001
|
p<0,000
|
|
Table 4.
Our New Score,
calculated before and after surgery,
showed a significant relationship with hemodynamic parameters evaluated respectively before and after PEA.
Another objective of our research consisted in evaluating the relationship between variation of radiological,
hemodynamic and clinical parameters at baseline and after surgery,
as displayed in Table 5.
|
improved |
unchanged |
worsened |
p value |
∅ main PA |
80%
|
16% |
4% |
<0.01 |
∅ right PA |
94% |
4% |
2% |
<0.01 |
∅ left PA |
92% |
4% |
4% |
<0.01 |
∅ RV |
84% |
10% |
6% |
<0.01 |
∅ RA |
81% |
15% |
4% |
<0.01 |
∅ LV |
56% |
19% |
27% |
>0.05 |
∅ SVC |
61% |
26% |
13% |
<0.01 |
∅ CS |
56% |
22% |
22% |
<0.01 |
∅AV |
51%
|
32% |
17% |
<0.01 |
RVFWT |
68% |
30% |
2% |
<0.01 |
TR |
65% |
33% |
2% |
<0.01 |
BAH |
15% |
79% |
6% |
>0.05 |
MP |
90% |
10% |
0% |
<0.01 |
CC |
0%
|
92% |
8% |
>0.05 |
ISB |
13% |
81% |
6% |
>0.05 |
NYHA |
59% |
41% |
0% |
>0.05 |
mPAP |
98% |
2% |
0% |
<0.01 |
PVR |
100% |
0% |
0% |
<0.01 |
|
Table 5. Changes of radiological,
hemodynamic and clinical parameters before and after PEA and the p value of each parameter evaluated before and after surgery.
All radiological parameters evaluated showed an improvement except for collateral circles (CC) (Fig.
2),
interventricular septum bowing (ISB) and BAH (Fig.
3) whom were unchanged respectively in 92%,
81% and 79% (Table 5).
MP evaluated before and after PEA showed a normalization in the 40% and a reduction of the group with severe grade of MP from 30% to 4 % (Fig.
4); TR grades were grouped as 1 as mild,
2 as moderate,
3 and 4 as severe and the severe grade declined from 30% to 4%.
As regards NYHA class variations the group that included NYHA III and IV passed from 92% of pre surgery to 34% in post PEA.
And NYHA I and II passed from 8% to 66%.
As shown in Table 5,
some radiological parameters did not show substantial modifications on CT executed after surgery; in particular,
it was observed that collateral circles,
BAH and leftward interventricular septum bowing did not change much after PEA.
This result could be related to a minor reversibility of these parameters after surgical intervention.
A significant statistical relationship was observed for mPAP and PVR (p<0.01) and for all continuous and categorical radiological parameters evaluated before and after PEA except for left ventricle,
BAH,
CC and ISB; in particular main PA (Fig.
5),
PA right and left branches,
right atrium and ventricle,
coronary sinus,
superior vena cava,
azygos vein,
right ventricle wall thickness,
TR and MP (p<0.01).
In addition,
mPAP correlated significantly with main PA diameter.
This result confirms the relationship between PA size and PH severity.
Some Authors [16,
17] also investigated this relationship in patients with CTEPH who underwent PEA,
coming to the same conclusions,
in particular,
among other parameters,
PA diameter measured on CT showed the strongest correlation with mPAP and the most significant reversibility after surgery [16].
Both mPAP and PVR showed a significant relationship with the evolution of mosaic perfusion (MP) evaluated on CT in our patients before and after PEA (Table 6).
|
mPAP pre
|
PVR pre
|
mPAP post
|
PVR post
|
MP pre
|
p=0,019
|
p=0,004
|
|
|
MP post
|
|
|
p=0,012
|
p<0,001
|
|
Table 6.
Statistical correlation between mosaic perfusion and mPAP and PVR before and after PEA.
This outcome reveals that patients with a major reduction of mPAP after PEA also showed a consistent improvement of mosaic perfusion pattern on CT.
This result can be explained as surgical disobstruction of pulmonary vessels causes both a reduction in mPAP values and the reperfusion of lung areas which were poorly vascularised before PEA,
with the consequent disappearance of hypoperfused lung areas on CT after surgical intervention.
A further aim of our study was evaluating the relationship between mPAP percent difference and variation in NYHA class after PEA; this variation was also expressed dividing our sample in improved,
unchanged and worsened patients.
We observed that mPAP percent difference correlated significantly with variation of NYHA class in our sample.
This data confirms the good correspondence between clinical and hemodynamic improvement after PEA and,
as many Authors already demonstrated [18,
19],
further confirms NYHA class as a useful parameter in the evaluation of clinical severity in patients with CTEPH.
As concerns the application of our new score in patients with CTEPH before and after PEA,
we demonstrated that it could accurately reflect hemodynamic changes.
In addition,
it was observed that patients with a greater reduction of our score,
calculated pre and post surgery,
also showed a consistent reduction of both mPAP and PVR values after PEA.
Our score seems to be useful in evaluating hemodynamic profile and consequently the severity of PH,
using only a CT exam; in this way our new index could be used in order to give cardiologists an estimate of hemodynamic changes in patients with CTEPH,
either in those who carry out the intervention and in those who cannot,
especially when a RHC is contraindicated or difficult to be performed.
The limitations of our study are due to the absence of ECG gating.