Results:
Quantitative variables were expressed as mean, standard deviation.
Qualitative variables were expressed as proportions.
Data analysis was done using SPSS version 16.0
According to the age group distribution of the disease (severe PHT) , we
can see from the fig 3 ,that the age group affected is mostly
from 20 yrs to 50 yrs (90.1 %) .This is a productive age group and
needs to be addressed carefully
While considering the sex of the population affected its seen that
females are slightly more affected (54.7%) compared to males (45.3%)
as evident from the fig 4.
On comparing the tables 1 and 2, we could decipher that most of the
patients in the preoperative period were in class III NYHA (67.5 %) and
were symptomatically improved to NYHA class II (68.7%). On performing
the chi square test it was statistically found to be significant p
<0.001
On statistically analyzing the results for the regression in Pulmonary
Hypertension following Mitral valve Replacement in our study, we could
definitely appreciate that the regression starts from the first month of
post surgical period and continues till 3 months post surgical period (p
0.026; p0.095) Table 3 which is quite significant statistically
.It’s quite interesting to note that the regression is not appreciable
after 3 months as is evident from the fig. 3
The Kaplan Meir curve depicts the drastic regression at 1 month of
surgery and gradual regression thereafter in the following months.
As far as the age groups are compared it’s not statistically seen that
significant regression occurs following Mitral Valvular Replacement due
to severe pulmonary Hypertension .In other words Age doesn’t influence
much in the regression of PHT after Mitral valve replacement in patients
with severe PHT preoperatively[Table 5 ] .
DISCUSSION :
Normal Pulmonary arterial pressure in a person living at sea level has a
mean value of 12–16 mm Hg (1600–2100 Pa). Pulmonary Hypertension is
present when mean Pulmonary artery pressure exceeds 25 mm Hg (3300 Pa)
at rest or 30 mm Hg (4000Pa) with exercise [9].
PHT can be idiopathic or familial with various underlying causes and
classifications. PHT classifications were modified regularly for better
understanding of the disease .the latest modification was done in Nice,
France 2013. [Table 1] The reduction of PHT following MVR is not
well understood and relies on various factors[10,11]. This is a
follow up study providing information on the agenda.
In all our 265 patients who underwent MVR, 195 had severe Pulmonary
Hypertension females 111/195(56.9%) outnumbered the males in this
diagnosis. The immediate reduction of Pulmonary Hypertension happened in
only approximately 21 % of the patients and the remaining had
persistent PHT which showed a fall progressively following a 1-3 months
period suggesting the various factors which might be responsible for the
Pulmonary Hypertension.
Yang and colleagues found the long term survival was inversely related
to the degree of PHT and had an early (30 day) mortality of 9% in
patients with severe PHT, However in our study it was found to be only
5.3% .But it needs further follow up of these patients in the long run.
[12].
Cesjnvar et al has reported higher early mortality among his series of
382 patients who underwent MVR for Mitral Valvular disease with
Pulmonary Hypertension. But the late mortality was no different among
patients with or without Pulmonary Hypertension [13].In our study
the mortality was 5.3%, which was less compared to the previous
studies. The difference might be because of the earlier decision to
operate upon this severe group before irreversible factors sets in and
also due to the better intraoperative and postoperative care using
latest agents so far approved for this purpose.
Most studies have demonstrated an immediate reduction in PAP and PVR,
signifying a sudden drop in left atrial pressure and reversal of the
severe spastic pulmonary vasoconstriction that accompanies left atrial
hypertension in some patients [10& 14]. Others have shown slow
regression of elevated PAP and PVR several months postoperatively
[14]. These reports point toward the involvement of multiple factors
in the development of PAH in mitral valve disease [14]. In our study
the mean PAP and PVR did not fall significantly immediately following
MVR. The mean fall in PAP was about 46.1mmHg in 1stmonth and 38.9 mmHg in the 3rd month follow up after
surgery, which was against the previous views.
Reduction of PHT is not random after MVR and is found to be reducing
gradually at 1 and 3 months in our study. This analysis showed that the
reduction in PHT had a gradual course. This gives us a clue that the
reduction in Pulmonary Hypertension is a gradual one and needed change
in organic level as well as in the dynamic level which takes some time
to achieve [15-20].
However, the long-term follow up of these patients are needed to
conclude firmly regarding reduction of PHT postoperatively.