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.