Abstract:
Background: Pulmonary Hypertension in mitral valvular heart
disease leads to various adverse outcome following surgical treatment of
this condition. In majority of the patients this Pulmonary Hypertension
is reversible following surgery. The objective of this study is to
assess the outcome of changes in Severe Pulmonary Hypertension after
Mitral Valve Replacement during the follow up with postop ECHO.
Patients and methods: In all our 265 patients who underwent
Mitral Valve Replacement Surgery (MVR) for Mitral valvular heart disease
with pulmonary hypertension, females 111/195(56.9%) outnumbered the
males in this study. 195 among 265 cases had severe PHT. MVR was done
with cardiopulmonary bypass using St Jude’s medical valve.
Results : Despite the high operative mortality in most series of
MVR in patients with severe PHT, a striking improvement in survival was
noted in the study with 5.3% mortality rate.A sudden drop of PHT is not
observed in our study. The fall was found to be gradual and significant
over follow up and the maximum reduction was at 1-3 months post
operatively.
Conclusion : It is concluded that MVR reduces PHT in a gradual
way and the mortality rate is also minimum in severe PHT patients. MVR
thereby is an effective invasive procedure for the management of
patients with severe mitral valve disease and PHT.
Keywords: Severe Pulmonary Hypertension, mitral valvular
disease, mitral valve replacement, Pulmonary artery pressure, Rheumatic
Heart Disease
INTRODUCTION :
Pulmonary Hypertension (PHT) is an increase in blood pressure in the
Pulmonary artery, Pulmonary vein, or pulmonary capillaries, together
known as the Lung Vasculature, leading to shortness of breath,
dizziness, fainting, and others Symptoms, all of which are exacerbated
by exertion. Pulmonary Hypertension can be a severe disease with a
markedly decreased exercise tolerance and heart failure[1].Patients
with Rheumatic Heart Disease develop Pulmonary Hypertension due to
various reasons and prime cause among them will be the retrograde
transmission of Left atrial hypertension which gets transmitted to the
Pulmonary arteries. Pulmonary venous pressure also is transmitted to
Pulmonary arteries. Pulmonary Arteriolar constriction, morphological
changes in Pulmonary Vasculature and Interstitial Oedema can also lead
to the development of Pulmonary Hypertension [1].
PHT was initially classified by World Health Organisation (WHO) as,
Group I - Pulmonary Arterial hypertension (PAH), WHO Group II -
Pulmonary Hypertension associated with left heart disease, WHO Group III
- Pulmonary Hypertension associated with lung diseases and/or Hypoxemia
and WHO Group IV - Pulmonary Hypertension due to chronic thrombotic
and/or embolic disease by the Venice 2003 revised classification system
[2].
Heath Edwards grading system classified PH into six grades based on
severity and pathophysiology of the disease. Usually Pulmonary
Hypertension grade 3 and below are reversible and can be taken up for
surgery with better results. Pulmonary Hypertension grade 4 and above
has significant contribution for postoperative morbidity and mortality
[3].
Catheterization studies are not done routinely as echocardiogram has
emerged as an effective tool to identify Pulmonary Hypertension and
classify accordingly.
Pulmonary Hypertension in mitral valvular heart disease leads to various
adverse outcomes following surgical treatment of this condition.
Pulmonary Hypertension is said to complicate about 70% of the patients
affected by this disease. Mitral valvular heart disease includes Mitral
stenosis (MS) which refers to narrowing of the mitral valve orifice and
Mitral valvular Regurgitation (MR) . It is usually caused by rheumatic
heart disease [4].
Pathophysiology of Pulmonary Hypertension in Mitral Valvular heart
disease in both Rheumatic Mitral Stenosis and Regurgitation can be
described as follows,
Elevated LA pressureElevated Pulmonary venous pressureTransmitted
pulmonary venous hypertension to arteriesVasoconstriction of Pulmonary
arteriolesPulmonary Artery HypertensionRight ventricular
dilatationTricuspid RegurgitationRight Atrial enlargementCongestive
cardiac failure. Pulmonary Hypertension greatly influences the natural
course of the disease process, treatment response and also the post
intervention prognosis [1, 4&7].
Features indicating severity of disease in mitral valvular lesions
complicated by pulmonary hypertension includes, Severe Subvalvular
Pathology, Small Mitral Valve Area, Higher Transvalvular gradient,
Higher Pulmonary valve resistance, Higher NYHA symptoms, Thickened non
pliable valves, Higher Wilkins score and Higher incidence of Atrial
Fibrillation[1,4].
Treatment options can be medical, interventional or surgical. Rate
control drugs like Betablocker and Calcium channel blockers help in
reducing the transmitral gradient and hence the PHT. Digoxin is usually
started for the failing heart and RV dysfunction which has to pump blood
against severe PHT [6].
In interventional method for isolated MS and PHT, Balloon Mitral
Valvotomy (BMV) is done in various centres .Balloon Mitral Valvotomy can
be attempted only if the valves are pliable and the Wilkins score is
favorable[6].There are many concerns before proceeding to BMV like
the less tolerance to the stress of the procedure, difficulty in
negotiating the septum in large right sided chambers, Tight Mitral
Stenosis and fear of tearing the mitral valve and creating Mitral
Regurgitation[6].
Various options are open for surgical management of Mitral Valvular
heart disease like Mitral valve replacement (MVR), Closed Mitral
Commisurotomy and Open Mitral Valvotomy. Mitral Valve Replacement may be
done with either mechanical prosthetic valve or Bioprosthetic Valve ,
Autologous transfer of Pulmonary valve (ROSS II PROCEDURE) has also been
done for this condition[6] .Pulmonary Hypertension regresses after
the transmitral gradient gets reduced following surgery[8].
The objective of this study is to analyze the reduction in Pulmonary
Hypertension following mitral valve replacement during patient follow up
post surgically.An attempt of a prospective study to analyze the facts
is made and the results are tabulated and compared to the national and
international views on the same parameter of this common disease. The
results obtained from the data collection were tabulated and analyzed.