Abstract
Surgical left ventricle restoration (SVR) was firstly by Cooley in 1958
with the “linear suture technique”, and three decades later, Dor used
a circular patch to reconstruct the left ventricle excluding the scarred
parts of the septum and ventricular wall. It gained popularity and
eventually almost abandoned after the contrasting literature evidences.
Hassanabad et al. presented a comprehensive review of current literature
on surgical ventricle restoration (SVR) techniques and clinical
outcomes, trying to understand if SVR has still a substantial role in
the modern medicine.
The worldwide human and economic burden of congestive heart failure (HF)
has rapidly grown in the last two decades with an estimated overall cost
of $108 billons per annum with $65 billons attributed to direct
expense accounted for by hospitalization and $48 billons to indirect
costs; US is responsible for 28.4% of total spend while Europe account
for 6.8% (1).
Heart transplantation remains the treatment of choice for patients with
medically refractory end-stage HF, nevertheless the need for
immunosuppression and the limited donor supply have restricted the
selection criteria, leaving physicians seeking for alternative therapies
(2,3).
Hassanabad et al. presented a comprehensive review of current literature
on surgical ventricle restoration (SVR) techniques and clinical
outcomes, trying to understand if SVR has still a substantial role in
the modern medicine. They also critically analysed data on left
ventricle morphology and size, mitral valve disfunction and arrhythmias
(4). Cardiac remodelling is generally accepted as a determinant of the
clinical course of HF and comprises changes in left ventricle cavity
diameters, mass, geometry and function. As early as few hours after
heart injury, the initial remodelling mechanism leads to reparation of
necrotic area through cellular rearrangement of the ventricular wall in
order to preserve cardiac output. As the heart remodels, the left
ventricle increase in diameter and become less elliptical and more
spherical (5). The rationale behind surgical ventricular restoration, as
we know, is to reverse left ventricle remodelling, restoring a more
physiological heart geometry and and improving mitral valve functioning
reducing left ventricle diameter and papillary muscle distances.
This “correction” was firstly described by Cooley in 1958 with the
“linear suture technique”, while three decades later, Dor used a
circular patch to reconstruct the left ventricle excluding the scarred
parts of the septum and ventricular wall. These techniques were adopted
and modified by many surgeons in the modern era (6,7).
Data on the performance of SVR are not univocal. The surgical Treatment
for Ischemic Heart Failure (STICH) Trial found that the addition of SVR
to coronary artery bypass grafting (CABG) reduce the end-systolic volume
index significantly compared with CABG alone; however this anatomical
conversion was not associated with a more favourable death-rate or
hospitalization for cardiac causes. Nonetheless, SVR may remain a
valuable strategy combined with CABG in selected HF patients with a scar
in the left anterior descending artery territory, especially if a
post-operative left ventricle end systolic volume (LVESV) index
< 70 mL/2 can be achieved, as recently reported by European
Society of Cardiology (ESC) and European Association for Cardio-
Thoracic Surgery (EACTS) (Class of Recommendation IIb; level of evidence
B) (8,9).
Ischemic mitral regurgitation (IMR) is a frequent complication of
chronic ischemic heart disease. In the failing heart, IMR occurs duo to
annular dilatation secondarily to left ventricle and papillary muscles
morphology and functional changes (10). The effects of mitral valve
surgery in patients with significant IMR in the setting of HF is still
controversial. H Wu et al. didn’t find any improvement in long-term
survival among more than one hundred patients with severe left ventricle
dysfunction that underwent mitral valve annuloplasty (11).
More recently the Randomized Ischemic Mitral Evolution (RIME) trial and
POINT trial demonstrated the efficacy of adding valve repair to CABG on
ventricular remodelling, ejection fraction, symptoms and degree of
mitral regurgitation but not with regard to mortality (12, 13,14).
The prognostic stratification of patients with ischemic cardiomyopathy
undergoing SVR is a potential area of future study and improvement for
surgical intervention. In this direction, Toso et al. demonstrated that
patients who underwent SVR with an elevated level of N-terminal
pro-B-type natriuretic peptide combined with presence of restrictive
filling pattern had the worst outcome in terms of mortality,
hospitalization for HF and major adverse cardiac events (MACE) at 36
months (15).
Magnetic resonance imaging (MRI) has been gaining popularity in the
context of HF, given the potential to identify the ideal candidates for
SVR procedure. Yamazaki et al. confirmed the importance of preoperative
LVESV index as a predictor of MACE following SVR. Patient with
preoperative LVESV index of >130 ml2 had
worst outcome compared to intermediate (LVESV index 100 to 130
ml2) and lower (LVESV index <100
ml2) group (16).
Right ventricle volume along function MRI assessment may also have
predictive value in the risk stratification of SVR. (17). As highlighted
by Hassanabad et al., the study of left ventricle myofiber orientation
and stress is now possible thanks the advance on MRI technology and
mathematical modelling. After successful SVR and aneurysm plication,
left ventricle myofibers orientation is significantly rearranged
resulting in a more uniform stress distribution and subsequently reduced
oxygen demand. Notably, given the most recent developments, MRI
technology is definitely a promising field of research in SVR prognostic
stratification.
Surgical restoration remains a complex procedure that and needs
multi-disciplinary approach. As such should be performed in high-volume
and specialized centres. However, there are evidences to suggest that it
might be a viable option for eligible / selected cardiac transplant
patients.