Comments
This retrospective, single-centre study evaluated the profile of
patients undergoing isolated TV surgery based on our surgical
experience. The overall postoperative course of patients undergoing
isolated TV surgery was complicated in approximately 43.6% of patients,
as arbitrarily defined by an ICU LOS ≥ 4days and/or total hospital LOS ≥
10days. We are aware that those cut-offs are not evidence based but, as
a matter of fact, clinical experience has demonstrated that these are
challenging patients in the vast majority of cases and that their
postoperative course usually needs an ICU stay longer than 24 hours,
even when no major complications occur. In our series, patients with a
longer postoperative stay developed complications usually related to
their more advanced disease at baseline, such as AKI, LCOS with the need
of inotropic support and infections. This also translated in a higher
in-hospital mortality, accounting for 13% within this subgroup. Only 3
patients, among those with a NEG postoperative course, experienced a
permanent neurological damage, which is unlikely to be explained by the
preoperative conditions. Although these events prolonged the ICU and
hospital stays of those 3 patients, we believe that such a small
percentage does not represent a relevant source of bias for our study.
As in other series20, our study confirmed that NEG
patients did have more advanced TV disease, with right ventricular
failure (RVF), high dose diuretic therapy, ascites, organ damage, RV
dysfunction and pulmonary hypertension. Despite being affected by more
advanced disease, when analysing the intraoperative characteristics of
the REG and NEG groups, both CPB and cross-clamp times were similar,
further supporting the fact that the outcome of these patients is not
related to TV surgery by itself, but mainly to the baseline profile of
the patients14. Even the adoption of a beating heart
approach was similarly distributed between the two groups and therefore
not related to the postoperative outcome.
In-line with previously published studies reporting the development of
late TR after left-sided heart surgery in 23-37% of
patients21,22, NEG patients had undergone more
frequently previous cardiac surgery and referred late for re-operation.
Consequently, due to the advanced stages of their disease, TVR rather
than TVr was unavoidable in the majority of them due to advanced RV
remodelling and tethering of the tricuspid leaflets, which might also
explain the higher percentage of new pacemaker implants in this group.
When analysing clinical predictors of poor outcome in patients in the
NEG group, chronic kidney disease doubles the risk of an unfavourable
course, together with ascites, previous right heart failure (RHF)
hospitalizations, more-than-moderate RV dysfunction, REDO interventions,
TV replacement and MELD score. These findings further underline the need
of early referral and early intervention for patients affected by
isolated TV disease3. Matter of factly, the MELD
score23 calculated for each patient, showed how
long-standing disease and multi-organ involvement, resulting in liver
dysfunction, was associated with overall worse outcomes. These findings
also underline how patients affected by chronic RVF might require a more
aggressive preoperative management, with either inotropic support or
mechanical support devices, in order to improve postoperative outcomes
and survival24,25.
Patients currently referred for tricuspid valve surgery are high-risk
individuals, frequently elderly, with a high percentage of
re-operations, high pulmonary artery pressure, end-stage functional
class and concomitant pathologies. Such patients and such scenarios
support the belief of the high-mortality rate associated to tricuspid
surgery, as also seen in our experience. In this context new
percutaneous technologies have been proposed but their effectiveness and
durability is still suboptimal26,27. To-date, the most
effective and durable treatment, when feasible with a reasonable risk,
remains surgery28. However, out data emphasize that
timely referral and early surgery are crucial to treat isolated TR with
a very low operative risk. As a matter of fact, patients who were
treated earlier, before organ damage, less pronounced RV
dilation/dysfunction and lower dose diuretics, could receive a repair
rather than a replacement procedure, with 1% postoperative permanent
pacemaker, acceptable rate of low-cardiac output syndrome and no
hospital mortality. Timing is of paramount importance in isolated
tricuspid valve surgery11 and should lead to a
thoughtful consideration of how misleading can be the assumption that
tricuspid valve surgery is by definition a high risk procedure. Isolated
tricuspid valve surgery, particularly repair, is indeed a very simple
operation which can be accomplished with a very low risk if carried out
for severe TR before development of symptoms (which are usually
expression of RV failure) and when only initial dilatation of the right
ventricular chamber is detected. Unfortunately, despite current
ESC/EACTS guidelines, this is almost never the case. Physicians and
patients are reluctant to propose and accept surgery in the absence of
symptoms and prefer waiting for their development and refractoriness to
high-dose of diuretics. At that stage patients present the features of
the NEG group of our study with the inevitable unfavourable outcome. Our
analysis identified several predictors of poor postoperative outcome in
a rather heterogeneous population of patients with isolated TR. Among
them diuretic dose and live enzymes emerged as independent risk factors
for this event. In our opinion this is a first step towards the
development of dedicated risk scores useful to predict the surgical
candidacy and the postoperative course of such challenging patients.
Nevertheless, our study further confirms that early referral is key to
really impact on outcome and prognosis of this population.