INTRODUCTION

The incidence of tricuspid regurgitation associated with left valvular disease is quite significant, ranging from 6 to 30 %. The most common association is with mitral valve but also related to aortic valve pathology. The tricuspid regurgitation is called ‘functional’ due to annular dilatation secondary to pulmonary hypertension and RV dilatation.^[1]

The approach that surgical treatment of left heart disease would correct the problem of right side is redundant now and tricuspid regurgitation is treated more aggressively. Patients who develop severe TR after left sided heart surgery have higher mortality rate, poor quality of life and reduced exercise tolerance.

Patients with late onset secondary TR progression after correction of left sided heart surgery need serial follow-up to ascertain redo surgery before the development of severe RV dysfunction. Timely referral is important before the onset of end organ damage. ^[2]

METHOD & OBSERVATION

The study included retrospective analysis of all patients (n=250) who underwent primary tricuspid valve surgery (n=208) along with left sided heart surgery or late for the secondary TR (n=42) appeared after left sided heart surgery without Tricuspid procedure. Preoperative and postoperative 2D Echo data was compared to Echocardiographic findings at the time of Redo surgery.

Table 1

2D Echo Findings

While the majority of patients who underwent Redo Tricuspid valve surgery were having mild TR and Tricuspid annulus less than 4 cm at the time of primary left sided surgery, late onset secondary TR seems to have progressed. Important predictors of late TR progression are high systolic PA pressure (54±14.7), atrial fibrillation (n=30) and enlarged left atrium diameter (49 ± 6.8 mm).

Table 2

Primary vs Redo Surgery (Patients Profile)

The age group of patients who underwent primary surgery was less (54 ± 15.2 years)

compared to Redo group (62 ± 8years). The majority of patients in the redo group were in NYHA class III & IV  (39/42 ) with 38.09 % patients having LV ejection fraction < 40 %. Incidence of infective endocarditis is comparable in both group while 30.9 %  patients are having renal dysfunction.

Table 3

Baseline Characteristics

While 11.9 % percent patient in the redo group had pre-op inotropic requirements, almost 14.28% patients presented in shock in the redo group. 10 patients had emergency surgery (23.81%) in the redo group compared to 13.85% patients in the primary group. 30 days mortality was 4.8% in primary group compared to 16.66% (7/42) in the redo group.

28 patients underwent tricuspid valve repair in the redo group while 14 patients had Tricuspid valve replacement. Clamp time was higher in the repair group 130±60 min vs 115 ±55 min.

Intubation period was higher for the replacement group. 6/14 patients stayed in the ICU for more than five days. Operative mortality was higher in the replacement group (28.57% vs 10.71%)

Table 4

Repair vs Replacement

35.71% patients in the redo replacement group were in low cardiac output state post-operatively. Almost (6/14) 42.85 % patient required dialysis for renal failure.

Incidence of stroke was comparable in both group (7.14%). Reoperation for bleeding was similar in both groups. Prolonged intubation in redo replacement meant more number of patients (35.71%) acquiring hospital acquired pneumonia.

Table 5

Postoperative Morbidity

DISCUSSION

The concomitant correction of functional tricuspid regurgitation secondary to left heart disease remains underused and an associated functional tricuspid regurgitation typically reveals a delayed correction of left-sided heart disease.

Secondary dilatation of the tricuspid annulus is present in vast number of patients with left heart disease, even in the absence of TR. This is a progressive disease that does not always resolve after the correction of left sided lesion ^[3]. Due to high mortality involved with Redo surgeries, many recommend medical treatment and delayed referral for surgery until right heart failure becomes refractory to medication.

The factors related to high mortality in redo surgery are high functional class, severe RV failure and dimensions, low Ejection Fraction, elevated pulmonary artery pressure, all of which are progressive. Association between atrial fibrillation and progression of TR in native valve or repaired valve is well demonstrated in many studies including ours. An early referral for surgery will drastically reduce the mortality in this clinical subset. ^[4]

Transthoracic Echo allows good assessment of RV diameters and functions in patients with TR. However it has limitations given the complex morphology of RV and most parameters are influenced by load conditions. The severity of TR, the degree of RV dysfunction, a tenting area > 1.63 sq. cm and depth of tethering >0.76 are good indicators of Tricuspid valve needing surgery. Cardiovascular MR is a good tool in the assessment of the LV and RV volumes and EF, considered independent predictors of residual TR post-surgery. ^[5]

The high mortality associated with Tricuspid valve replacement in redo group could be due to large rigid prosthesis inserted into a deformable, low –pressure right ventricular cavity could lead to progressive right ventricular dysfunction. Despite more TR in the repair group during follow up, reoperation rates and functional class were similar.

The extended Intensive care stay with prolonged ventilation is associated with reduced survival in this study. It could be a reflection of patients with underlying lung disease or reflection of patients with pulmonary hypertension. On a similar note prolonged bypass time and postoperative low cardiac output syndrome are associated with reduced survival, a reflection of severity of underlying cardiac disease. ^[6]

We demonstrated that patients with NYHA Class III/IV had significantly poor outcomes. To improve outcomes, timely referral before end organ damages is very important. Surgical correction of TR at the time of primary surgery should be pursued more aggressively if patient is in Chronic AF, increased pulmonary artery pressure with dilated tricuspid annulus.

It’s quite obvious that despite good left heart surgery, TR doesn’t go away or get better overtime.