Prophylactic tricuspid intervention
Carpentier was one of the first authors to recommend tricuspid annular dilation as a more objective parameter to indicate TV repair. His evaluation method consisted in TV surgical exploration, checking the annulus ability to admit three fingerbreadths of the surgeon’s hand, in which case TV repair would be indicated16.
Three decades later, Dreyfus et al. evaluated tricuspid annuloplasty performed concomitantly with MV surgery in the presence of intraoperative tricuspid annular diameter ≥ 70mm, measured from the anteroseptal commissure to the anteroposterior commissure, regardless the preoperative TR grade. In a 5-year follow-up, TR degree, as well as patients’ functional status, was significantly lower in the TV treated group10.
Regarding echocardiographic measurement, evaluating 50 patients submitted to MV replacement due to rheumatic disease, Colombo et at. suggested that tricuspid annulus diameter > 21 mm/m2 could be a reliable parameter to indicate concomitant TV repair in this specific patient population17.
Similarly, using a tricuspid annulus dimension ≥ 40mm (> 21mm/m2) measured preoperatively in transthoracic echocardiography (TTE) 4-chamber view as a cut-off to indicate concomitant TR intervention, Van deVeire et al. demonstrated better reverse right ventricular remodeling and less postoperative TR prevalence, when compared with isolated MV surgery18. Figure 1 illustrates echocardiographic tricuspid valve evaluation, and Figure 2 a TR surgical repair using an annuloplasty ring.
In 2012, Benedetto et al. conducted a randomized trial enrolling 44 patients with less-than-severe TR (≤ + 2) and annular dilatation (≥ 40mm) treated at the same time that MV surgery. Early results demonstrated the safety of the combined approach (1 case of 30-day mortality in each group), with just a discreet increase in cardiopulmonary bypass and aortic cross-clamping time. After 12 months, those patients who underwent TV intervention presented with significant TR reduction (TR absent in 71% vs. 19%; p=0.001), improvement in functional capacity (6 min walking test: +115 ± 23m vs. +75 ± 35m; p=0.008), and right ventricular reverse remodeling [right ventricle long-axis 71 ± 7mm preoperative vs. 65 ± 8mm postoperative (p<0.01) and short-axis 33 ± 4mm preoperative vs. 27 ± 5mm postoperative (p=0.01) in TV treated group; right ventricle long-axis 72 ± 6mm preoperative vs. 70 ± 7mm postoperative (p=0.08), and short-axis 34 ± 5mm preoperative vs. 33 ± 5mm postoperative (p=0.1) in TV non-treated group]19.
Two-years after this publication, Chikwe et al. tested the association of an aggressive concomitant prophylactic TV repair (annular dilatation ≥ 40mm or ≥ moderate TR) in patients undergoing MV repair for degenerative diseases. No increased 30-day mortality and morbidity, lower TR progression rate, reduced pulmonary hypertension and improvement in induced right ventricle recovery were observed at 7-year follow-up20.
Regarding guideline recommendations, the American Heart Association/American College of Cardiology and the European Society of Cardiology/European Association for Cardio-Thoracic Surgery have recommended TR repair concomitant with left-sided surgery in the presence of annular size ≥ 40mm (> 21mm/m2), regardless of TR degree, as a Class IIa of recommendation21,22, which still means a low level of evidence.