2017 Volume 81 Issue 10 Pages 1432-1438
Background: Whether there is a significant difference in the long-term surgical outcomes between suture annuloplasty and ring annuloplasty for the treatment of functional tricuspid regurgitation (TR) is still controversial. We compared the long-term outcomes of tricuspid annuloplasty (TAP) with and without an annuloplasty ring.
Methods and Results: From January 1996 to December 2015, we consecutively enrolled 684 patients (mean age, 65.5 years; 60% women) undergoing TAP for functional TR: 312 underwent conventional suture annuloplasty (Group S) and 372 underwent ring annuloplasty (Group R). Baseline characteristics were comparable between the 2 groups, except for age and the prevalence of prior cardiac surgery. The mean follow-up period was 7.3 years (range, 0.3–20.3 years).There was no significant difference in overall survival, freedom from major adverse cardiac and cerebrovascular events, and freedom from recurrent moderate to severe TR between Groups S and R, although postoperative mean TR grade and sPAP were significantly lower in Group R. Multivariate analysis revealed that age, prior cardiac surgery, and preoperative severe TR were independent predictors of recurrent moderate or greater TR.
Conclusions: There was no significant difference in the long-term surgical outcomes between ring and suture TAP, although postoperative mean TR grade was lower in the ring annuloplasty group.
Tricuspid regurgitation (TR) secondary to chronic left-sided valvular disease is a common finding, but was for decades a “forgotten disease” because of the clinically greater importance of left-sided valvular disease.1 However, appropriate and aggressive surgical treatment of TR, regardless of its grade, is now recommended at the time of repair of left-sided valvular lesions,2,3 because moderate to severe TR has been associated with a poor prognosis regardless of cardiac function or pulmonary artery pressure,4,5 and significant TR often does not regress after successful surgical correction of left-sided valvular disease and may actually progress.6,7 According to the 2014 guidelines of the American College of Cardiology/American Heart Association, concomitant tricuspid valve (TV) repair or replacement for patients with severe TR at the time of left-sided valvular surgery is recommended as a class I indication.8
With respect to the management technique for functional TR, tricuspid annuloplasty (TAP) is more common and seems to have less risk than TV replacement.9 Over time, the more commonly used technique has shifted from suture annuloplasty to ring annuloplasty. However, whether secondary TR should be repaired with or without a prosthetic annuloplasty ring remains controversial because there are many confounding factors, including variable patient background and the absence of standardization of surgical techniques.10 Several studies have demonstrated the superiority of ring annuloplasty over suture annuloplasty.11–15 However, others have supported suture annuloplasty, pointing out its predominance or the shortcomings of ring annuloplasty, such as moderate to severe TR remaining in approximately 10% of patients after TAP using prosthetic rings,9 an increased risk of early ring dehiscence after the use of a rigid ring,16,17 and the satisfactory early and long-term outcomes of suture annuloplasty.18,19
The purpose of this study was to examine our long-term outcomes of TAP with or without an annuloplasty ring, and to assess the risk factors for recurrent TR.
From January 1996 to December 2015, a total of 792 consecutive patients underwent TAP for functional TR at the National Cerebral and Cardiovascular Center in Osaka, Japan. Patients who underwent concomitant left ventricular assist device implantation (n=96) or suture annuloplasty using the Kay technique (n=12) were excluded. Finally, 684 patients were enrolled. Among them, 312 patients underwent TAP with suture annuloplasty using the De Vega technique (Group S) and 372 underwent ring annuloplasty (Group R). In Group R, either a rigid ring (n=282) or a flexible ring (n=90) was used. The rigid ring was a Carpentier-Edwards “classic” Ring (Edwards Lifesciences, Irvine, CA, USA; n=7), Edwards MC3 Annuloplasty System (Edwards Lifesciences; n=233), Contour 3D Annuloplasty System (Medtronic, Minneapolis, MN, USA; n=35), or Carpentier-Edwards Physio Tricuspid Annuloplasty Ring (Edwards Lifesciences; n=7). The flexible ring was a Duran AnCore Annuloplasty Ring (Medtronic; n=14), Cosgrove-Edwards Annuloplasty System (Edwards Lifesciences; n=17), or SJM Tailor Flexible Annuloplasty Band (St. Jude Medical, Minneapolis, MN, USA; n=59). Clinical and echocardiographic data were collected and analyzed retrospectively. The institutional review board approved this retrospective study and waived the need for written consent.
Echocardiography was routinely performed before and 1 week after the operation and, if possible, annually during the follow-up period. All studies were analyzed by the cardiologists at the National Cerebral Cardiovascular Center using standard criteria to assess the degree of TR, which was graded on a scale of 0 to 4 (0, none; 1, trivial; 2, mild; 3, moderate; 4, severe).20 Systolic pulmonary artery pressure (sPAP) was estimated by continuous-wave Doppler of the TR jet using the modified Bernoulli equation and right atrial pressure, which was estimated according to inferior vena cava size.10 The indications for TAP included grade 3 or 4 TR and/or pulmonary hypertension (sPAP >50 mmHg) and/or TV annular dilatation (>21 mm/m2) and/or symptomatic right heart failure (HF).
The preoperative patient characteristics are summarized in Table 1. The mean age at operation was 65.5 years, and 60% of the patients were female. Approximately 60% of the patients had New York Heart Association class III or IV HF preoperatively. The mean body surface area was 1.51 m2. Approximately 25% of the patients had undergone prior cardiac surgery, and 3% of the patients had undergone pacemaker implantation. The majority of patients (76.6%) had atrial fibrillation.
| All (n=684) |
Group S (n=312) |
Group R (n=372) |
P value | |
|---|---|---|---|---|
| Age, years | 65.5±10.2 | 62.9±10.1 | 67.9±9.7 | <0.01 |
| Sex, female | 404 (59.1) | 185 (59.3) | 219 (58.9) | 0.87 |
| BSA, m2 | 1.51±0.18 | 1.51±0.21 | 1.51±0.18 | 0.86 |
| NYHA class | 2.7±0.6 | 2.7±0.6 | 2.6±0.6 | 0.99 |
| III or IV | 420 (61.4) | 200 (64.1) | 220 (59.1) | 0.78 |
| Prior cardiac surgery | 167 (24.4) | 92 (29.5) | 75 (20.2) | 0.04 |
| Prior pacemaker implantation | 20 (2.9) | 8 (2.6) | 12 (3.2) | 0.44 |
| Hypertension | 224 (32.7) | 93 (29.8) | 131 (35.2) | 0.08 |
| Diabetes mellitus | 94 (13.7) | 41 (13.1) | 53 (14.2) | 0.31 |
| Chronic kidney disease | 87 (12.7) | 33 (10.6) | 54 (14.5) | 0.24 |
| Atrial fibrillation | 524 (76.6) | 248 (79.5) | 276 (74.2) | 0.19 |
| Old cerebral infarction | 72 (10.5) | 39 (12.5) | 33 (8.9) | 0.12 |
Data are presented as mean±standard deviation or n (%). BSA, body surface area; NYHA, New York Heart Association; R, ring annuloplasty; S, suture annuloplasty.
The preoperative echocardiographic data are shown in Table 2. A total of 492 (71.9%) had moderate or severe TR, and the preoperative sPAP was >50 mmHg in almost 30% of the patients.
| Group S (n=312) | Group R (n=372) | |||||
|---|---|---|---|---|---|---|
| Preoperative | At discharge | Follow-up | Preoperative | At discharge | Follow-up | |
| Mean LVFS, % | 33.2±9.3 | 29.6±8.6 | 30.9±9.6 | 33.4±8.5 | 28.9±8.9 | 30.7±9.3 |
| Mean TR grade | 2.8±0.8 | 1.2±0.9a | 1.7±1.0a | 2.7±0.8 | 0.8±0.8a,b | 1.0±0.8a,b |
| Severe TR | 65 (20.8) | 4 (1.3) | 15 (4.8) | 89 (23.9) | 1 (0.3) | 3 (0.8) |
| Moderate TR | 170 (54.5) | 21 (6.7) | 50 (16.0) | 168 (45.2) | 23 (6.2) | 18 (4.8) |
| Mean sPAP, mmHg | 49.0±16.4 | 29.0±13.2a | 38.0±12.5a | 47.3±16.1 | 28.2±14.7a | 33.2±14.2a,b |
| sPAP >50 mmHg | 110 (35.3) | 15 (4.8) | 23 (7.4) | 113 (30.4) | 19 (5.1) | 28 (7.5) |
Data are presented as mean±standard deviation or n (%). aP<00.05 vs. preoperative value; bP<00.05 vs. Group S. LVFS, left ventricular fractional shortening; sPAP, systolic pulmonary artery pressure; TR, tricuspid regurgitation. Other abbreviations as in Table 1.
The standard operative technique has been previously described.21 Left-sided valvular disease was corrected first. In patients with atrial fibrillation, a modified Cox maze IV procedure was performed using a cryoablator. After a right atriotomy, the TV was inspected and TAP was normally performed with or without an annuloplasty ring under cardioplegic arrest. In patients who underwent ring annuloplasty, the ring size was based on the surface area of the anterior leaflet and/or the length of the septal annulus and downsized by 1–2 sizes. An annuloplasty ring was fixed with 9–12 stiches of 3-0 braided polyester suture, which were placed from beyond the anteroseptal commissure to the middle of septal leaflet. De Vega annuloplasty was performed using a 3-0 double-armed expanded polytetrafluoroethylene suture with a small Teflon pledget, which was tightened to reduce the annular diameter generally to 28 mm. The suture was doubly placed from the anteroseptal commissure to the posteroseptal commissure. All patients underwent intraoperative transesophageal echocardiography.
The choice of TAP technique, including selection of a prosthetic ring, depended on the surgeon’s preference. As a result, suture annuloplasty was mainly performed in the early study period (1996–2005), whereas ring annuloplasty was mostly done in the late study period (2006–2015) (Table 3). Almost all (99.8%) patients underwent a concomitant procedure. Mitral valve surgery was performed in almost 90% of the patients, and the modified Cox maze IV procedure was performed in 38% of the patients (Table 3).
| All (n=684) |
Group S (n=312) |
Group R (n=372) |
P value | |
|---|---|---|---|---|
| CPB time, min | 173±57 | 176±58 | 171±56 | 0.24 |
| AXC time, min | 119±42 | 117±45 | 121±39 | 0.43 |
| Concomitant procedure | ||||
| MV replacement | 419 (61.3) | 201 (64.4) | 218 (58.6) | 0.48 |
| MV repair | 190 (27.8) | 76 (24.4) | 114 (30.6) | 0.39 |
| Aortic valve replacement | 154 (22.5) | 80 (25.6) | 74 (19.9) | 0.47 |
| CABG | 47 (6.9) | 18 (5.8) | 29 (7.8) | 0.23 |
| Maze | 261 (38.2) | 110 (35.3) | 151 (40.6) | 0.26 |
| Date of operation | <0.0001 | |||
| 1996–2005 | 305 (44.6) | 276 (88.5) | 29 (7.8) | |
| 2005–2015 | 379 (55.4) | 36 (11.5) | 343 (92.2) | |
Data are presented as mean±standard deviation or n (%). AXC, aortic cross-clamp; CABG, coronary artery bypass grafting; CPB, cardiopulmonary bypass; MV, mitral valve. Other abbreviations as in Tables 1,2.
Complete follow-up was achieved in 95.5% of the patients, with a mean follow-up of 7.3±5.7 years (range, 0.3–20.3 years; median, 5.7 years; Group S, 10.7±5.8 years; Group R, 4.2±3.4 years, P<0.01). The follow-up was closed on 15 April 2016. The follow-up data were obtained from hospital clinical records, including echocardiogram reports, mailed questionnaires, and telephone interviews with the patients, their family members, or physicians. Echocardiographic data were available for all patients preoperatively and for 678 patients (99.1%) at least once postoperatively. The mean duration of echocardiographic follow-up was 5.5±5.2 years (Group S, 8.8±5.5 years; Group R, 3.0±3.1 years). The events investigated were death from any cause, major adverse cardiac and cerebrovascular events (MACCE), which included cerebral infarction or hemorrhage, reoperation for any cause, permanent pacemaker implantation, prosthetic valve infection, congestive HF requiring hospital readmission, mediastinitis, and death.
Statistical AnalysisContinuous variables are expressed as mean±standard deviation and were compared between groups using Student’s unpaired t-test. Categorical variables are expressed as number of patients (%) and were compared between groups using the chi-squared test. The Kaplan-Meier method was used to calculate the survival and recurrence-free rates. Risk factors for recurrent TR were evaluated using Cox multivariate regression analysis. Data were analyzed using JMP (Version 10; SAS Institute Inc., Cary, NC, USA), and differences were considered statistically significant at a P value of <0.05.
Patient background characteristics included sex, New York Heart Association class, body surface area, and morbidity of preoperative complications and were similar between the 2 groups. However, patients in Group R were significantly older, and previous cardiac operations were more frequent in Group S (Table 1). There were no significant differences between the 2 groups in preoperative left ventricular fractional shortening, TR grade, or mean sPAP (Table 2). As shown in Table 3, the cardiopulmonary bypass time, aortic cross-clamp time, and prevalence of concomitant procedures were similar in both groups.
Mortality and MorbidityThe 30-day mortality rate was 1.3% (n=4) in Group S and 1.1% (n=4) in Group R. The causes of death in Group S were methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis, low-output syndrome, preoperative cardiogenic shock, and liver dysfunction originating from liver cirrhosis; those in Group R were acute respiratory distress syndrome, MRSA mediastinitis, left ventricular rupture after the 5th cardiac surgery, and sudden death.
During the follow-up period, 89 patients in Group S and 39 in Group R died. The respective cumulative survival rates at 1, 3, and 8 years were 95.9%, 94.0%, and 82.1% in Group S and 97.8%, 94.7%, and 82.1% in Group R (Figure 1). There was no significant difference in the actuarial survival rate between the 2 groups. There was also no significant difference in freedom from MACCE between the 2 groups. Respective freedom from MACCE at 1, 3, and 8 years was 89.1%, 88.4%, and 68.4% in Group S and 90.8%, 85.9%, and 63.8% in Group R (Figure 2).
Overall actuarial survival rate of patients undergoing annuloplasty for the treatment of functional tricuspid regurgitation, estimated by the Kaplan-Meier method. R, ring annuloplasty; S, suture annuloplasty.
Overall actuarial freedom from major adverse cardiac and cerebrovascular events (MACCE) of patients undergoing annuloplasty for the treatment of functional tricuspid regurgitation, estimated by the Kaplan-Meier method. CHF, congestive heart failure; PMI, pacemaker implantation; PVE, prosthetic valve endocarditis; PVF, prosthetic valve failure; R, ring annuloplasty; S, suture annuloplasty.
There were only 4 cases of TV reoperation for recurrent TR: 3 cases in Group S and 1 in Group R. The patient in Group R underwent TV replacement using a bioprosthesis and the other 3 patients underwent repeat TAP using an annuloplasty ring. The indication for TV reoperation was recurrent severe TR with symptomatic left-sided or/and right-sided HF. The cause of recurrent TR requiring reoperation was annular re-dilation in Group S and dehiscence of a rigid ring in Group R. The respective interval between the initial operation and reoperation was 30, 51, 158 months in Group S and 80 months in Group R. A total of 48 patients underwent postoperative permanent pacemaker implantation and of them 10 required a pacemaker within 1 month postoperatively and 38 patients eventually underwent pacemaker implantation.
Echocardiographic AssessmentBoth sPAP and the mean TR grade significantly improved postoperatively in both groups (Table 2). However, sPAP and the mean TR grade in both groups seemed to deteriorate during the follow-up period without a statistically significant difference. The mean TR grade at discharge and during follow-up was significantly lower in Group R than in Group S, and sPAP during follow-up was significantly lower in Group R than in Group S (Table 2).
Recurrent TRThe respective rates of freedom from recurrent moderate or greater TR at 1, 3, and 8 years were 97.0%, 94.7%, and 85.3% in Group S and 98.7%, 97.6%, and 86.9% in Group R (Figure 3). There was no significant difference between the 2 groups.
Postoperative freedom from recurrent moderate to severe tricuspid regurgitation (TR) in patients undergoing annuloplasty for the treatment, estimated by the Kaplan-Meier method. R, ring annuloplasty; S, suture annuloplasty.
Univariate analysis and subsequent multivariate analysis revealed that recurrent moderate or greater TR during the follow-up period was significantly associated with patient’s age (P=0.035, hazard ratio 1.031), previous cardiac surgery (P=0.005, hazard ratio 2.175), and preoperative severe TR (P=0.0004, hazard ratio 2.645). Suture annuloplasty was not an independent risk factor for recurrent moderate or greater TR on logistic regression analysis (Table 4).
| Univariate | Multivariate | HR | 95% CI | |
|---|---|---|---|---|
| P value | P value | |||
| Age | 0.029 | 0.035 | 1.031 | 1.002–1.062 |
| Female | 0.314 | |||
| BSA | 0.793 | |||
| NYHA class | 0.206 | |||
| Prior cardiac surgery | 0.001 | 0.005 | 2.175 | 1.277–3.671 |
| Prior pacemaker implantation | 0.018 | 0.302 | 1.739 | 0.570–4.299 |
| Hypertension | 0.918 | |||
| Diabetes mellitus | 0.543 | |||
| Chronic kidney disease | 0.743 | |||
| Atrial fibrillation | 0.771 | |||
| Old cerebral infarction | 0.141 | |||
| Suture annuloplasty | 0.474 | |||
| Preoperative severe TR | <0.0001 | 0.0004 | 2.645 | 1.560–4.419 |
| Preoperative sPAP >50 mmHg | 0.047 | 0.055 | 1.668 | 0.989–2.774 |
| CPB time | 0.310 | |||
| AXC time | 0.529 | |||
| MV replacement | 0.773 | |||
| MV repair | 0.438 | |||
| Aortic valve replacement | 0.507 | |||
| CABG | 0.883 | |||
| Maze | 0.290 |
CI, confidence interval; HR, hazard ratio. Other abbreviations as in Tables 1–3.
TR is a common echocardiographic finding observed in 80–90% of healthy individuals.4 Mostly, the volume of TR is small and it may have been tolerated for years. On the other hand, moderate or severe TR has been associated with poor short- and long-term survival, and an aggressive approach to TR is warranted.4,5,22 Surgical correction of significant functional TR at the time of left-sided valvular surgery is recommended,22,23 but there is no consensus on the optimal surgical approach.4,15,24
Suture annuloplasty using the De Vega technique25 can preserve the anatomy and flexibility of the TV annulus and is an easy, fast, and cost-effective method.19 Good short- and long-term outcomes of suture annuloplasty have been shown.10,18,19 However, these results have been questioned by others who have reported recurrent TV annular dilatation or suture disruption requiring reoperation.9,12,24 The concept of ring annuloplasty, which was developed by Carpentier et al,26 involves removal of tension from the suture line and prevention of recurrent annular dilatation.27 Several studies have provided evidence supporting ring annuloplasty over conventional suture annuloplasty.11–15
In the present study, we assessed our 20-year experience of TAP with and without a prosthetic ring and found that the overall rates of survival, freedom from MACCE, and freedom from recurrent moderate to severe TR were satisfactory regardless of annuloplasty technique. In our study, the survival rate at 10 years was 77.8% in Group S and 78.2% in Group R, and freedom from recurrent moderate or greater TR at 8 years was 85.3% in Group S and 86.9% in Group R. On the other hand, a meta-analysis performed by Parolari et al, which included 9 major reports, demonstrated a survival rate at 10 years of 66.3±2.0% in the whole study group, and freedom from recurrent moderate TR at 8 years of 81.8±2.0% in the suture annuloplasty group and 88.5±2.0% in the ring annuloplasty group.15
Intriguingly, Kaplan-Meier analysis showed no significant difference in the rates of survival, freedom from MACCE, or freedom from recurrent moderate to severe TR between the 2 groups in our study. Our outstanding outcomes for suture annuloplasty might have led to these results. The quality of the material and the manner of reducing the annular size might explain our good results for suture annuloplasty. We have generally reduced the tricuspid annular size to fit a 28-mm or smaller bougie using an expanded polytetrafluoroethylene suture, whereas many researchers reduce the tricuspid annular size to 3 finger breadths utilizing 3-0 polypropylene suture.14,28 To reduce the TV orifice, we assent to the concept of “overcorrection” proposed by Shinn et al, who routinely narrow the TV orifice to a diameter of 20 mm.10,23 We also focused on the stitches placed on the TV annulus. By close observation, we detected a small vessel in the triangle of Koch approximately 10–15 mm distant from the anteroseptal commissure in most cases.21 We believe that this might indicate the location of the atrioventricular node. We thus started placing a suture immediately next to the observed vessel beyond the anteroseptal commissure for both De Vega annuloplasty and ring annuloplasty. This technique might have contributed to our good outcomes in both groups.
In our experience, there was a discrepancy; although the postoperative mean TR grade and sPAP were significantly lower in Group R than Group S, there was no significant difference in the Kaplan-Meier estimates of survival between the 2 groups. As to the association between TR severity and survival, Santas et al reported that the association was significant only in patients with HF with preserved ejection fraction (EF), with increasing mortality risk as TR became more severe.29,30 They also demonstrated that the severity of functional TR was a reflection of the severity of left-sided HF in HF with reduced EF, and not just simply a reflection of the severity of left-sided HF but might be an reflection of the severity of integrated cardiac and noncardiac pathophysiological conditions in HF with preserved EF.29,30 Although their study cohort was patients with acute HF, differing from ours, their concept might explain the discrepancy found in our study, because 48% of the patients were preoperatively classed as HF with reduced left ventricular function (FS <30%).
In our study, Cox multivariate regression analysis revealed that preoperative severe TR, previous cardiac surgery, and age were independent predictors of recurrent moderate or greater TR, similar to other reports.9,12,14,28,31 McCarthy et al found that risk factors for recurrent TR included a higher degree of preoperative TR, as well as left ventricular dysfunction, the presence of a transtricuspid pacing lead, and TAP without a ring.9 Other well-known risk factors are atrial fibrillation, right ventricular dysfunction, and pulmonary hypertension,10,12,28,31,32 which were not independent predictors in the present study. Only 4 patients underwent TV reoperation in our series, which contrasted with the rate of recurrent moderate to severe TR. This discord in the results might be explained by the fact that reoperation was associated with high mortality and by the actual status of our patients, the majority of whom were asymptomatic with no significant left-sided valvular disease. Therefore, late reoperation rates may underestimate late failure of valve repair.
There are 2 types of prosthetic ring: rigid rings and flexible rings. Which is superior to the other remains controversial.3,14,33 In our series, a rigid ring was used in 76% of the patients in Group R. Most of these rings have a 3D design that can adopt and maintain the saddle configuration of the native TV annulus.33,34 On the other hand, flexible rings can fit the complex annular geometry and follow its dynamic motion during the cardiac cycle.35 This is similar to the merit of suture annuloplasty: preserving the flexibility of the tricuspid annulus and right ventricular pumping action.28 The importance of physiological tricuspid annulus motion and geometry during the cardiac cycle is still unclear. Further investigation comparing the outcomes and morphological changes after TAP between rigid and flexible ring is necessary.
Study LimitationsThis study has several intrinsic limitations. First, it was not a randomized trial but a retrospective and observational study in a single center with a limited number of patients. Additionally, the follow-up period for patients who underwent ring annuloplasty was relatively short. Second, the time of the operation and accordingly the surgeons differed between the groups. Over the time of the study period, the diagnostic evaluation, operative techniques, perioperative management, and patient population might have changed. Additionally, the choice of surgical technique for TAP was dependent upon the individual surgeons’ judgment and preference; it might have also been based on the historical background of TAP. Therefore, the operative background might not have been homogeneous between the 2 groups. Third, the annuloplasty rings used for TAP in this study varied. Finally, we lacked a detailed assessment of both TV structure, including the annulus diameter or TV leaflet tethering, and right ventricular function before and after the operation. A prospective randomized study with a longer follow-up period and larger number of patients should be performed. Further assessment including right ventricular function and TV anatomic information may improve our understanding and help to detect other predictors of recurrent TR. Despite these limitations, our study has considerable strength, including a relatively large number of patients and long follow-up time with adequate patient follow-up rate (95.5%) and echocardiographic follow-up rate (99.1%).
In the present study, there was no significant difference in the overall rates of survival, freedom from MACCE, and freedom from recurrent moderate to severe TR between ring annuloplasty and suture annuloplasty, although postoperative TR grade was lower in the ring annuloplasty group. Preoperative severe TR, previous cardiac surgery, and age were independent predictors of recurrent moderate or greater TR. Further follow-up including close echocardiographic observation is needed because the follow-up period after ring annuloplasty in the present study was limited and TR may deteriorate at a later time after TAP.
The authors declare that no conflicts of interest exist.
None.
