Shedding some light on tricuspid intervention
Khalil Fattouch, MD, PhD1. Marco Moscarelli, MD,
PhD2.
1 Department of Cardiovascular Surgery, GVM Care and
Research, Maria Eleonora Hospital, Palermo – Italy.
2 Department of Cardiac Surgery, GVM Care and
Research, Anthea Hospital, Bari-Italy
Corresponding author:
Marco Moscarelli
GVM Care & Research, Anthea Hospital
Via Camillo Rosalba 1571
Bari (BA) 90135, Italy
Tel: +39 091 698 1111
E-mail: m.moscarelli@imperial.ac.uk
Conflict of interest : none
Word count: 1282
We read with interest the Meta-analysis performed by Sarris-Michopoulos
et al, that aimed to investigate the role of tricuspid valve repair
(TVr) versus replacement (TVR) in patients with isolated tricuspid valve
regurgitation (TR) (1).
Patients with first time surgery for isolated TR without previous
left-side valve surgery were included in this paper. Ten studies were
screened for a total of 1407 patients included in the quantitative
analysis. Authors conclude that patients who underwent TVr showed less
30-days mortality and postoperative pacemaker implantation rates.
This study in addition to the meta-analysis recently published by Wang
et al (2), that included more than 15000 patients, might shed a light in
a grey area. The issue investigated by authors in fact is still a matter
of investigation. The 2021 ESC/EACTS guidelines for the management of
valvular heart disease (3), recommended surgery (class 1) in symptomatic
patients with isolated severe primary or secondary TR without severe
right ventricular (RV) dilatation/dysfunction or severe pulmonary
hypertension (PH). Surgery should be considered (class 2a) for
asymptomatic or mildly symptomatic patients with isolated primary severe
TR and RV dilatation who are appropriate for surgery. In the 2020
ACC/AHA valvular heart disease guideline (4) surgery should be
considered (class 2a) for patients with isolated severe primary or
secondary TR with signs and symptoms of right-side heart failure in the
absence of severe PH and RV dysfunction to reduce symptoms and recurrent
hospitalizations.
More than 1.6 million Americans have at least moderate to severe TR, yet
fewer than 8000 TV operations are performed annually in the USA.
Historically, isolated primary TR was thought to be limited to patients
with congenital heart disease and secondary TR is associated with PH and
left-side valvular or myocardial pathology.
In the last decade, the incidence of isolated TR appears to be rising
along with the prevalence of atrial fibrillation (AF), heart failure and
the presence of intracardiac devices.
The under-treatment for isolated TR could be due to the fact that in the
past years there are no clear guidelines to guide how and when to treat
TR.
Quantification by trans-thoracic echocardiography often is not accurate
because regurgitation grade is related to several conditions such as
preload, after-load and RV function. Preload is often decreased by
vasodilators and diuretics therapies and after-load is often/always
pulmonary or left-side related. Right ventricular function assessment by
echo isn’t accurate and its role is underestimated when the right
ventricle is chronically failing.
MRI scan is perhaps the best way to assess RV function, shape, and
stroke volume but not widely available. We should aim to investigate not
only the severity of TR but also to the TV/RV morphology. Shape of the
RV (from elliptical to spherical), TV annular dilatation, mismatch
between leaflets and annular dimension, lack of leaflets coaptation and
tethering should be accurately evaluated. Once all these features are
present, absence or grade of TR can be misleading as any changes in
preload under medical therapy and after-load can unmask severity of TR.
Isolated moderate to severe TR is associated with worse outcomes and is
a highly detrimental condition for which a prompt intervention should be
applied timely. The clinical impact of isolated TR was described first
by Nath, J. et al in 2004 (5). In a cohort study of 5223 patients, the
presence of severe TR was associated with decrease survival after
adjustment for PH and ejection fraction (Hazard Ratio (HR): 1.31, 95%
CI 1.05, 1.66). Similarly, Topilsky, et al. found that patients with
isolated severe TR hade worse long-term survival (HR 2.67, 95% CI 1.66
to 4.23) and even in the absence of significant cardiopulmonary
comorbidities, adversely affected outcomes (6).
On the other side, there are little data about timing of surgery in
patients with isolated severe TR. Several studies investigate the
relationship between right atrial pressure and RV function with outcomes
in patients undergoing TV surgery. In patients undergoing stand-alone TV
surgery, RV end-systolic dimension, RV end-systolic area and the RV
index of myocardial performance have all been associated with survival
free of death, heart failure, cardiac readmissions, and TV reoperation
(6-8). Authors found that RA pressure and RV function were key
determinants of postoperative outcomes.
These findings suggest early surgery for patients with isolated severe
TR. Surgical treatment is based on several clinical observations. First
of all, progressive RV dysfunction drives further annular dilatation and
results in more severe TR; hence, TR begets more severe TR. Medical
therapy will not reverse RV dysfunction. Once severe right heart failure
symptoms develop and TR remains untreated there is progressive clinical
deterioration with development of end-stage liver and kidney failure and
surgical options become either inappropriate or compassionate.
The current high mortality associated with surgery for isolated severe
TR may be related to late surgical referral and furthermore early
surgery should be performed before end-organ damage have already
occurred.
Tricuspid valve repair should be the first option when possibile.
Careful evaluation of the morphology of the TV and RV should be applied.
Patients with pure annular dilatation without severe lack in leaflets
coaptation and thetering (coaptation high less than 0.8cm) may be
treated by prosthetic annuloplasty. In cases of severe leaflets
thetering, lack in coaptation and mismatch between leaflets and annulus,
pericardial patch augmentation of the anterior leaflet in concomitant to
ring annuloplasty might be performed. In patients with intracardiac
device and lead-to-leaflet adherence present, lead extraction or shaving
with leaflet mobilization should be done in concomitant to other repair
procedures. In these cases, when repair approach is challenge, TVR with
exteriorisation of the lead outside the valve ring could be an optimal
option. On the other side, in case of lead extraction or when conduction
disturbances are anticipated, epicardial implantation should be
performed as part of the initial operation.
Residual and recurrent regurgitation after tricuspid valve annuloplasty
are common. Residual TR occurs in 10%-14% of patients early after
annuloplasty (9). Suture-annuloplasty are associated with more recurrent
regurgitation rate than the prosthetic ring. The higher the grade of
preoperative TR, the higher the risk of repair failure within 6 months.
Factors as permanent pacemakers, ventricular dysfunction and suture
annuloplasty were identified as a risk for late regurgitation. To
improve repair outcomes, suture annuloplasty should be avoided and lead
pacemaker correctly managed.
In term of in-hospital complications, TVr had lower rates mortality,
lower postoperative renal failure and pacemaker implantation. Obviously,
TVr procedure in complex anatomical scenario should be performed in
heart valve reference centre by high skill surgeons.
When TVr is not feasible, TVR could be a good option (10). The choice
between mechanical or biological prosthesis is still debated. Recently,
Cheng Z et al published a systematic review and meta-analysis
investigating the role of mechanical versus biological prostheses for
tricuspid valve replacement (11). In tricuspid valve position,
mechanical valve prostheses have higher risk of thrombosis than
biological prostheses, but no differences between both was emerged
respect to prosthetic valve failure, bleeding, reoperation, early
mortality and long-term survival. Negm et al found an equal risk of
30-day and late mortality, reoperation and 5-year valve failure in
patients with mechanical versus biological TVR (12). The choice of the
prosthesis in the tricuspid position should depend mainly on patient’s
age, valve disease, and risk factors because of non-superiority of one
over the other. In the current era of percutaneous treatment biological
prosthesis could be preferred in perspective of future valve-in-valve
intervention.
In conclusion, TVr is associated with lower mortality and postoperative
complication rates respect to valve replacement. The operative risk of
both procedures remains high probably due to late referral. Further
investigations and experience with regard to earlier surgery, optimizing
medical therapy for reverse RV remodelling, and percutaneous
interventions for inoperable/high risk patients are necessary to improve
outcomes in this challenging issue.