DISCUSSION:
Congestive heart failure (CHF) is the commonest heart problem in the
world and is currently one of the leading causes of death and
hospitalization in the older age group [1].
Left ventricular remodeling involves two mechanisms: restriction of
valve movements and disappearance of cooptation. Then, The vicious
circle: ventricular remodeling-mitral insufficiency. Functional mitral
regurgitation occurs in the absence of structural mitral valve disease.
Given the better understood mechanisms of mitral regurgitation in
dilated cardiomyopathies, the purpose of mitral plastic is therefore to
restore a cooptation surface between the valve sheets by reducing the
native ring by an undersized circumferential prosthetic ring to obtain
valvular continence.
Indeed, the plane of computation of the two valve sheets, due to the
hypertraction of the ropes, is moved towards the apex of the ventricle
and moves away from the plane of the ring, resulting in a “tent”
effect, increasing the covering surface necessary of the two mitral
sheets to obtain the closure of the mitral orifice, and this to the
detriment of the coaptation surface [2].
It is well established that secondary mitral regurgitation worsens both
symptoms and prognosis in patients with left ventricular dysfunction of
ischemic and non-ischemic etiology.
Cardiac transplantation has been the standard treatment for patients
with severe CHF associated with end-stage heart disease. However, this
therapeutic modality has limited applicability.
Alternate surgical strategies to manage patients with severe end stage
heart disease have been applied over the last decade or more, including
resynchronization therapy, electrical therapy, coronary artery
revascularization, cardiomyoplasty, left ventricular myoreduction
surgery and mitral valve repair.
Bolling et al. were the first to report the early outcome of remodeling
mitral annuloplasty with a flexible posterior ring in 16 patients with
severe CHF and mitral regurgitation in 1995[3].
Szalay et al. reported a similar experience among 121 patients with
mitral regurgitation and cardiomyopathy having a left ventricular
ejection fraction less than 30% [4].
Bolling has emphasized also in many presentations the importance of the
undersizing of the flexible ring in reestablishing the ellipsoid shape
and somewhat normal geometry of the left ventricular base [5].
Early and intermediate results with implantation of an undersized
flexible ring in the posterior mitral annulus suggests that correction
of functional regurgitation results in partial reversal of left
ventricular remodeling and in symptomatic improvement. Intermediate
results are superior to medical treatment alone and comparable to
cardiac transplantation [6].
CONCLUSION :
The optimal treatment of functional mitral regurgitation in heart
failure patients is still controversial.
Apart from guideline-directed optimal medical therapy, cardiac
resynchronization therapy, a durable mitral valve repair has the
potential to improve cardiac reverse remodeling and prognosis.