Short-term prognosis of patients in different stages of severe tricuspid regurgitation after transcatheter tricuspid-valve replacement

Introduction

Previous studies have shown that severe tricuspid regurgitation (TR) affects patient prognosis adversely (1-3). However, TR, which is mainly caused by secondary etiologies, has been under-treated, with only 5% of severe-degree patients receiving surgical treatment (4); this may be due to the high perioperative mortality of surgical procedures (5,6). With the development of transcatheter tricuspid valve technology, perioperative mortality has decreased significantly (7,8), thus the timing of interventions for TR becomes critical. Previous studies have shown higher morbidity and mortality during hospitalization after TR surgery in patients with coexisting chronic kidney disease and liver disease. Currently, the Tricuspid Regurgitation In-hospital mortality score (TRI-SCORE) is widely used for risk stratification to predict outcomes in patients undergoing tricuspid valve surgery. However, its validation is primarily based on surgical cohorts (9), and its predictive accuracy in transcatheter tricuspid valve interventions remains insufficiently established. A recent study (10) applied a modified TRIVALVE score to assess prognosis in transcatheter tricuspid valve intervention patients. However, this score incorporates a limited number of parameters and stratifies patients into only two risk categories (low- and high-risk), without adequately accounting for the impact of extra-cardiac organ damage from TR on overall prognosis. More recent studies have regarded extra-cardiac manifestations of TR as comorbidities rather than part of the TR disease process. However, based on the pathophysiology of TR, the concept of “tricuspid regurgitation syndrome” has been proposed (11), which can help to identify hemodynamic disorders secondary to TR and enable us to quantify its impact on patients. The aim of this study was to classify TR stages based on this concept of TR syndromes and analyze the short-term prognosis of patients in different stages after transcatheter tricuspid valve replacement (TTVR) by the LuX-Valve Plus system. We present this article in accordance with the STROBE reporting checklist (available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2692/rc).

Methods

Study population

This study involves a post-hoc analysis of patients enrolled in the first-in-man and confirmatory study and the investigator-initiated trial of the LuX-Valve Plus system. The former study was a prospective, multicenter, single-arm, and objective performance criteria-based clinical investigation, which aimed to evaluate the safety and efficacy of a trans-jugular tricuspid valve system (the LuX-Valve Plus) for surgically inoperable patients (12). The latter trial was a prospective and single-center study evaluating the safety and efficacy of LuX-Valve Plus for transjugular TTVR in surgically inoperable or high-risk patients (Table S1). This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Both studies were approved by the Ethical Committee of West China Hospital of Sichuan University (approval Nos. 12.2022 and 13.2023) and informed consent was provided by all participants. Patients presenting with at least severe TR from 12 centers in China, who met the indication of TTVR and underwent isolated TTVR by the LuX-Valve Plus from May 2022 to March 2024, were included in this analysis. The flow chart of patients enrolled in this study is shown in Figure 1. Patients with a history of transcatheter intervention for heart diseases were excluded. All patients were divided into three groups according to the stages of TR syndrome.

Figure 1 Flow chart of patients enrolled in the present study. RV, right ventricular.

Staging of the TR syndrome

All patients underwent preprocedural echocardiographic assessment for TR according to the grading criteria proposed by Hahn et al. (13). All patients were graded according to the “tricuspid valve syndrome” classification proposed by our team. The assessment of tricuspid valve syndrome included: (I) cardiac involvement: cardiac function, cardiac structural changes, pulmonary hypertension, and N-terminal pro-brain natriuretic peptide (NT-Pro-BNP); (II) respiratory involvement: forced expiratory volume in the first second <50% or estimated diffusion capacity for carbon dioxide <50%; (III) liver and spleen involvement: abdominal color Doppler assessment; and (IV) renal involvement: the filtration rate. The staging of TR syndrome was defined as: (I) stage 1: no clinical symptoms; (II) stage 2: solely cardiac symptoms; (III) stage 3: damage of 1 extracardiac system; and (IV) stage 4: damage of 2 or more extracardiac systems (11).

Patient data and follow-up

Baseline demographic, laboratory test values, echocardiography, and perioperative data were collected from all patients. The right ventricular (RV) size (including the anterior-posterior diameter, the basal diameter, the mid diameter, the longitudinal diameter), the right atrium (RA) volume, the left atrium (LA) volume (Figure S1), and the RV function (Figure S2) was assessed before the procedure, and at 7- and 30-day follow-up. The process of TTVR by the LuX-Valve Plus was reported previously (12,14-16). All patients with successful LuX valve placement underwent follow-up 1 month after the procedure. Endpoints, including all-cause death, heart failure rehospitalization, and cardiovascular-related death, were collected.

Statistical analysis

Binary categorical variables were described by count and percentages (%). Continuous variables were described by mean with standard deviation or median (25th quantiles, 75th quantiles), depending on the distribution of the data. Comparisons between groups were conducted by one-way analysis of variance (ANOVA), Mann-Whitney test for continuous variables, and by chi-square test, Fisher exact test for binary categorical variables. Comparisons among different time points were conducted by paired sample t-test (two time points) or Kruskal-Wallis rank sum test (three time points). A P value of <0.05 was considered statistically significant. All statistical analyses were performed using the software SPSS 26.0 (IBM Corp., Armonk, NY, USA. Figures were created using GraphPad Prism 10.0 (GraphPad Software, San Diego, CA, USA).

Results

Baseline characteristics

A total of 149 patients were included, of whom 23 were in stage 2, 49 in stage 3, and 77 in stage 4. As shown in Table 1, among the three groups, participants in the stage 4 group was significantly older (74.00±8.30 vs. 71.18±8.98 vs. 68.65±7.84 years, P=0.017), presented more often with lower limbs edema, atrial fibrillation, pulmonary diseases, as well as a higher Society of Thoracic Surgeon (STS) score (10.16%±5.27% vs. 8.02%±3.65% vs. 7.62%±4.05%, P=0.012) and the Model for End-Stage Liver Disease (MELD)-Albumin score (9.01±2.79 vs. 7.11±1.93 vs. 6.94±1.77, P<0.001). The 6-minute walk distance (6MWD) was greatest in the stage 2 group. No significant differences were observed in the presence of New York Heart Association (NYHA) class III–IV, frailty, and the Kansas City Cardiomyopathy Questionnaire (KCCQ) scores among the three groups. Patients in stage 4 also had higher levels of creatinine, total bilirubin, direct bilirubin, and NT-Pro-BNP, whereas the levels of hemoglobin, platelet count, and estimated glomerular filtration rate (eGFR) were lower.

There was no difference in TR etiology among the three groups, with functional TR being the dominant etiology. Based on the definition by Russo et al. (17), 101 patients were classified as having atrial functional TR, whereas 32 had ventricular functional TR. There was no significant difference in pulmonary artery pressure and the presence of aortic regurgitation (AR) and mitral regurgitation (MR). However, TR was more severe in the stage 4 group, and its mean vena contracta width was significantly larger than that of the stage 3 and stage 2 groups (14.94±4.51 vs. 11.13±4.56 vs. 11.04±3.71 mm, P<0.001). The inferior vena cava was also significantly enlarged in the stage 4 group (26.31±6.82 vs. 20.71±5.51 vs. 21.13±5.71 mm, P<0.001), and the tricuspid annulus was more dilated in the stage 4 group than in the stage 3 and 2 groups (44.87±5.41 vs. 41.54±6.21 vs. 42.13±5.26 mm, P=0.004). Meanwhile, the right ventricle was significantly larger in the stage 4 group, and the RV longitudinal diameter had no significant difference. The RA was also larger (171.86±81.52 vs. 127.27±66.71 vs. 121.40±47.90 mL, P=0.001) in the stage 4 group than in the stage 3 and 2 groups. The left ventricular size and biventricular systolic function, including RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), and left ventricular ejection fraction (LVEF), were not significantly different among the three groups.

In-hospital outcomes

All patients receiving TTVR successfully underwent echocardiographic and laboratory assessment 7 days after the procedure. As shown in Table 2, there was no significant difference in maximal velocity and mean pressure gradient across the LuX-Valve Plus and the presence of central TR among the three groups, but paravalvular leakage (PVL) was significantly higher in the stage 4 group (13 vs. 4 vs. 0), and RV mid diameter (37.44±8.23 vs. 33.06±7.72 vs. 36.13±5.10 mm, P=0.038) as well as RV end-diastolic area (24.12±9.56 vs. 18.48±6.01 vs. 21.03±5.76 cm², P=0.003) were significantly larger in the stage 4 group than that in the stage 3 and 2 groups. Patients in stage 4 continued to have larger RA volume (145.85±82.88 vs. 102.36±67.58 vs. 106.71±48.42 mL, P=0.019). The end-diastolic diameter, LVEF, and LA volume were comparable between the three groups.

Hemoglobin, platelets, and albumin decreased in all groups after the procedure, and the decrease was more pronounced in the stage 4 group. Creatinine and NT-Pro-BNP levels were still the highest and eGFR remained the lowest in the stage 4 group. The differences between the stage 4 group and the other 2 groups in terms of the levels of total bilirubin and direct bilirubin were reduced.

As shown in Figure 1, 4 of the 158 patients were converted to surgery and two patients could not achieve successful access to the right ventricle. Other adverse events happened in 5 of the 149 patients (3.36%), including 2 cases of acute gastrointestinal bleeding, 2 valve stent abnormality, and 1 vascular injury. No abnormality in device function, prosthetic thrombosis, and prosthesis vegetation of the LuX-Valve Plus was observed. No in-hospital death was noted.

One-month follow-up

The results of 1-month follow-up are shown in Table 3. A proportion of 95.3% (142/149) of patients finished the 30-day follow-up. All-cause mortality was 1.41% (2/142), of which 1 was a cardiovascular-related death (presented with acute kidney failure, acute liver failure, mechanical ventilation >72 hours, and cardiovascular injury requiring surgical treatment). Other composite events included 1 case of severe PVL and conversion to surgery, 6 cases of new-onset third-degree atrioventricular block requiring permanent pacemaker, 2 cases of acute renal failure, and 4 cases of severe PVL. No rehospitalization due to heart failure at 30-day follow-up was observed.

At 1 month, 96 patients underwent the 6-minute walk test and 104 were assessed for KCCQ score. There were no significant differences in 6MWD, KCCQ score, and the presence of NYHA class III–IV among the three groups. The laboratory results were consistent with baseline and 7 days after TTVR, with decreased hemoglobin, platelet, eGFR, and increased creatinine in the stage 4 group.

Echocardiography was performed in 142 patients 1 month after intervention. The stage 4 group continued to have wider inferior vena cava than the stages 3 and 2 groups (21.41±5.83 vs. 17.60±4.54 vs. 17.88±4.65 mm, P=0.001), more frequent mild central regurgitation and moderate PVL. The RV size, FAC, RA volume, LA volume, LVEF, and left ventricular end-diastolic diameter (LVEDD) were not significantly different among the three groups.

Structural and functional changes of the heart and extracardiac system after TTVR

As shown in Figure 2, all RV diameters decreased significantly after the procedure. The RV end-diastolic area showed a downward trend in all patients, and more significantly in the stage 4 group. The FAC decreased after the procedure. Figure 3 shows that LA and RA volume did not statistically change, whereas LVEDD tended to decrease overall after implant, especially in the stage 4 group.

Figure 2 Right ventricular structural and functional changes of different stages before, post-TTVR and 1 month after trans-jugular tricuspid valve replacement. Structural and functional changes of heart and extracardiac system after TTVR. All RV diameters decreased significantly after the procedure. The RV end-diastolic area showed a downward trend in all patients, and more significantly in stage 4 group. The FAC decreased after the procedure. FAC, fractional area change; RV, right ventricular; TTVR, transcatheter tricuspid valve replacement.

Figure 3 Atrium and left ventricular structural changes of different stages before, post-TTVR, and 1 month after trans-jugular tricuspid valve replacement. It showed that LA and RA volume did not statistically change, whereas LVEDD end diastolic diameter tended to decrease overall after implant, especially in stage 4 group. LA, left atrium; LVEDD, left ventricular end-diastolic diameter; LV, left ventricular; RA, right atrium; TTVR, transcatheter tricuspid valve replacement.

Figure 4 compares the recovery of cardiac function 1 month after the procedure, showing that all patients benefited from the TTVR. The percentage of NYHA class III–IV significantly decreased, and KCCQ score significantly increased compared with that at baseline. Figure 5 indicates that hemoglobin, platelets, and albumin fluctuated after the procedure, with the mean level of albumin in the stage 4 group presenting the lowest at 7 days after TTVR. NT-Pro-BNP levels increased shortly after the procedure and then decreased, whereas the diameter of inferior vena cava decreased persistently in all groups. There was no significant difference of eGFR, the levels of total bilirubin, direct bilirubin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) among groups.

Figure 4 NYHA class (left) and KCCQ (right) of different stages before and 1 month after trans-jugular tricuspid valve replacement. Comparing the recovery of cardiac function 1 month after the procedure, it showed that all patients had benefited from the TTVR. Percentage of NYHA class III–IV significantly decreased, and KCCQ score significantly increased compared with that at baseline. KCCQ, Kansas City Cardiomyopathy Questionnaire; NYHA, New York Heart Association; TTVR, transcatheter tricuspid valve replacement.

Figure 5 Blood test results changes of different stages before, post-TTVR, and 1 month after trans-jugular tricuspid valve replacement. It indicated that hemoglobin, platelet, and albumin fluctuated after the procedure, with the mean level of the albumin in the stage 4 group presenting the lowest 7 days after TTVR. NT-Pro-BNP levels increased shortly after the procedure and then decreased, whereas the diameter of inferior vena cava decreased persistently in all groups. There was no significant difference of eGFR, the levels of total bilirubin, direct bilirubin, ALT, and AST among groups. ALT, alanine aminotransferase; AST, aspartate aminotransferase; eGFR, estimated glomerular filtration rate; NT-Pro-BNP, N-terminal pro-brain natriuretic peptide; TTVR, transcatheter tricuspid valve replacement.

Discussion

The TR syndrome comprises a classification established according to the cardiac and extracardiac manifestations (11). This study reported the baseline characteristics and short-term follow-up of patients in different stages of TR syndrome based on multicenter experience with the LuX-Valve Plus system, and the main findings were as follows: (I) TR patients with extracardiac involvement were common and all benefited from TTVR; (II) RV reverse remodeling was observed after TTVR; (III) NYHA functional class and KCCQ scores improved after TTVR; (IV) extracardiac parameters changed transiently after TTVR, but the overall trend was not significant in the short-term follow-up; (V) increased risk of death and PVL was observed in the stage 4 group.

This study found that 84.6% (126/149) of patients undergoing TTVR were in stages 3 and 4, and extracardiac involvement is not uncommon in TR, which is consistent with the high burden of comorbidity of TR reported in previous studies (4,18). Indeed, more severe regurgitation, larger annulus and right heart chambers, higher NT-Pro-BNP levels, and higher surgical risk were observed in stage 4 patients, but traditional measures of cardiac function, such as the 6-minute walk test, NYHA class, frailty score, and KCCQ score, did not show significant differences. This demonstrated the elusive nature of TR in terms of symptoms, providing a possible reason for the delay of TR treatment. In addition, this suggests that the assessment of TR population should not be limited with only traditional cardiac function, but a more comprehensive and systemic evaluation should be considered. Assessment of extracardiac manifestations secondary to TR may better quantify the impact of TR on patient prognosis and thus identify the optimal timing for TR intervention.

In early TTVR experience, liver cirrhosis and advanced renal failure had been the only causes of in-hospital death (8). Of the 2 patients who died in this study, 1 died of acute liver failure and renal failure, and the other patient died of sudden circulatory collapse. This confirmed the importance of the role of liver and kidney function in TR disease progression. However, in this short-term observation, there was no significant change in the level of eGFR, whereas the albumin presented a great extent of changes after the procedure. Although the liver function indicators including bilirubin, ALT, and AST fluctuated perioperatively, no statistical significance was observed. This indicated that TTVR plays a neutral role in terms of the alteration of liver and kidney function of TR patients at the short-term follow-up. The long-term effects of TTVR on liver and kidney function should be further investigated.

Patients receiving TTVR in this study presented a drop in the levels of hemoglobin, platelets, and albumin and a sharp increase in BNP after the procedure. Most of the patients had benefited from TTVR at short-term follow-up in terms of the right heart structure and cardiac function assessment indicated by parameters such as right chamber size, NYHA class, and KCCQ score. This benefit was independent of stage, but presented a more pronounced trend in the stage 4 group. It is worth noting that the LVEF of all patients was normal, which may be one of the reasons for the clinical benefit. In addition to the reversal remodeling changes of the right ventricle, a decrease in the LVEDD, being particularly remarkable in the stage 4 group, was observed, which indicated certain benefit of TTVR to achieve left ventricular reverse remodeling. Right heart failure has been thought to be a cause of alleviate the symptoms of left heart failure by reducing left ventricular volume. This result indicated the suitability of TTVR for TR patients with right heart failure without affecting the left-sided heart function. However, whether this phenomenon occurred exclusively in patients with normal LVEF requires further supporting data.

The TTVR technology could almost completely eliminate TR compared to tricuspid valve repair which only achieves partial correction (7,19-21). Therefore, the reverse remodeling of RV may be more significant in patients receiving TTVR. It is worth noting that baseline FAC was generally normal, which may be a prerequisite for the occurrence of marked reverse remodeling of the right ventricle, given previous studies have found that reduced RV systolic function may lead to adverse RV remodeling (22,23). Our measurements of RV size included RV anteroposterior diameter, RV basal diameter, RV intermediate diameter, RV long diameter, and RV end-diastolic area. The middle diameter of the right ventricle was more sensitive to the changes before and after the intervention, which may be related to the mechanism that the enlargement of the right ventricle usually begins with the free wall. This also indicates that the measurement of RV diameter in the four-chamber view should be considered in terms of the measurement of right ventricle size, which is consistent with previous studies (24,25). At the same time, the systemic venous pressure decreased significantly, as manifested by the reduction of the diameter of the inferior vena cava. In accordance with previous studies (24,26), we also observed a decrease in FAC shortly after TTVR, which may be a masked decrease in RV function due to severe TR.

Reported perioperative mortality of TTVR has been low (24,27-31). In this study, both of the 2 deaths occurred in the stage 4 group. Meanwhile, the stage 4 group was also complicated with more frequent moderate or more severe PVL. The absence of a significant difference in mortality may be related to the small sample size. However, the increased incidence of PVL did suggest a higher risk profile for patients in stage 4. This may be due to the more significant right heart deformation and annular dilatation in patients in stage 4, resulting in increased technical difficulty of the procedure and narrower device adaptation. These findings implicate the importance of early intervention for TR.

Limitations

Although this was a multicenter prospective single-cohort study, the sample size was small with inherent bias. This study only analyzed short-term prognosis of 1-month follow-up. Thus, the long-term effect of the TTVR by the LuX-Valve Plus system remains to be determined.

Conclusions

Staging of TR syndrome may help to quantify disease severity. Although patients in all stages can gain short-term benefits from TTVR, an early intervention of TR may help to reduce the risk of complications.

Acknowledgments

We would like to thank Zhongshan Hospital, Fudan University; Changhai Hospital of Shanghai; Yunnan Fuwai Cardiovascular Hospital; Beijing Anzhen Hospital, Capital Medical University; Tongji Medical College, Huazhong University of Science and Technology; Department of Cardiovascular Surgery, West China Hospital, Sichuan University; Department of Cardiology, West China Hospital, Sichuan University; The First Affiliated Hospital of Air Force Medical University; Guangdong Provincial People’s Hospital; The Second Affiliated Hospital, Zhejiang University School of Medicine; Xiamen Cardiovascular Hospital, Xiamen University; and The Affiliated Union Hospital of Fujian Medical University for their invaluable contributions to this study and the provision of essential research data.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2692/rc

Data Sharing Statement: Available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2692/dss

Funding: This work was supported by the National Natural Science Foundation of China (Nos. U23A20395 and 82170375); Sichuan Science and Technology Program (Nos. 2024NSFSC1715 and 2023NSFSC1707); Chinese Medical Association Cardiovascular Branch (CSC) Clinical Research Special Fund Project (No. CSCF2020B04); and 1·3·5 Project for Disciplines of Excellence-Clinical Research Fund, West China Hospital, Sichuan University (No. 2023HXFH009).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2024-2692/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. This study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Both studies were approved by the Ethics Committee of West China Hospital of Sichuan University (approval Nos. 12.2022 and 13.2023) and informed consent was provided by all the patients.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Nath J, Foster E, Heidenreich PA. Impact of tricuspid regurgitation on long-term survival. J Am Coll Cardiol 2004;43:405-9. [Crossref] [PubMed]
2. Jia KY, Chen F, Peng Y, Wei JF, He S, Wei X, Tang H, Meng W, Feng Y, Chen M. Multidetector CT-derived tricuspid annulus measurements predict tricuspid regurgitation reduction after transcatheter aortic valve replacement. Clin Radiol 2023;78:779-88. [Crossref] [PubMed]
3. Neuhold S, Huelsmann M, Pernicka E, Graf A, Bonderman D, Adlbrecht C, Binder T, Maurer G, Pacher R, Mascherbauer J. Impact of tricuspid regurgitation on survival in patients with chronic heart failure: unexpected findings of a long-term observational study. Eur Heart J 2013;34:844-52. [Crossref] [PubMed]
4. Taramasso M, Gavazzoni M, Pozzoli A, Dreyfus GD, Bolling SF, George I, Kapos I, Tanner FC, Zuber M, Maisano F, Hahn RT. Tricuspid Regurgitation: Predicting the Need for Intervention, Procedural Success, and Recurrence of Disease. JACC Cardiovasc Imaging 2019;12:605-21. [Crossref] [PubMed]
5. Dreyfus J, Flagiello M, Bazire B, Eggenspieler F, Viau F, Riant E, et al. Isolated tricuspid valve surgery: impact of aetiology and clinical presentation on outcomes. Eur Heart J 2020;41:4304-17. [Crossref] [PubMed]
6. Alqahtani F, Berzingi CO, Aljohani S, Hijazi M, Al-Hallak A, Alkhouli M. Contemporary Trends in the Use and Outcomes of Surgical Treatment of Tricuspid Regurgitation. J Am Heart Assoc 2017;6:e007597. [Crossref] [PubMed]
7. Taramasso M, Alessandrini H, Latib A, Asami M, Attinger-Toller A, Biasco L, et al. Outcomes After Current Transcatheter Tricuspid Valve Intervention: Mid-Term Results From the International TriValve Registry. JACC Cardiovasc Interv 2019;12:155-65. [Crossref] [PubMed]
8. Hahn RT, George I, Kodali SK, Nazif T, Khalique OK, Akkoc D, Kantor A, Vahl TP, Patel A, Elias E, Ng V, Spina R, Bartus K, Velagapudi P, Wu I, Leon M, Bapat V. Early Single-Site Experience With Transcatheter Tricuspid Valve Replacement. JACC Cardiovasc Imaging 2019;12:416-29. [Crossref] [PubMed]
9. Dreyfus J, Audureau E, Bohbot Y, Coisne A, Lavie-Badie Y, Bouchery M, et al. TRI-SCORE: a new risk score for in-hospital mortality prediction after isolated tricuspid valve surgery. Eur Heart J 2022;43:654-62. [Crossref] [PubMed]
10. Russo G, Pedicino D, Pires Marafon D, Adamo M, Alessandrini H, Andreas M, et al. TRIVALVE Score: A Risk Score for Mortality/Hospitalization Prediction in Patients Undergoing Transcatheter Tricuspid Valve Intervention. JACC Cardiovasc Interv 2024;17:2170-9. [Crossref] [PubMed]
11. Lu F, Xiong T, Chen M. Evaluation of systemic impact of tricuspid regurgitation: an appeal for the notion of tricuspid regurgitation syndrome. Chin Med J (Engl) 2023;136:138-40. [Crossref] [PubMed]
12. Pan X, Lu F, Wang Y, Guo Y, Chen M, Meng X, et al. Transcatheter Tricuspid Valve Replacement With the Novel System: 1-Year Outcomes From the TRAVEL Study. JACC Cardiovasc Interv 2025;18:1276-85. [Crossref] [PubMed]
13. Hahn RT, Badano LP, Bartko PE, Muraru D, Maisano F, Zamorano JL, Donal E. Tricuspid regurgitation: recent advances in understanding pathophysiology, severity grading and outcome. Eur Heart J Cardiovasc Imaging 2022;23:913-29. [Crossref] [PubMed]
14. Wei X, Li X, Liang Y, Chen F, Zhao Z, Feng Y, Chen M. Transcatheter tricuspid valve replacement with LuX-valve device: Overview of key echocardiographic considerations. Catheter Cardiovasc Interv 2024;104:1517-35. [Crossref] [PubMed]
15. Zhang Y, Lu F, Li W, Chen S, Li M, Zhang X, Pan C, Qiao F, Zhou D, Pan W, Ge J. A first-in-human study of transjugular transcatheter tricuspid valve replacement with the LuX-Valve Plus system. EuroIntervention 2023;18:e1088-9. [Crossref] [PubMed]
16. Ning X, Cao J, Wang W, Zhou G, Yang F, Xu Z, Han L, Qiao F, Lu F. 4-Year Follow-Up after Transatrial Transcatheter Tricuspid Valve Replacement with the LuX-Valve. J Cardiovasc Dev Dis 2022;9:435. [Crossref] [PubMed]
17. Russo G, Badano LP, Adamo M, Alessandrini H, Andreas M, Braun D, et al. Characteristics and outcomes of patients with atrial versus ventricular secondary tricuspid regurgitation undergoing tricuspid transcatheter edge-to-edge repair - Results from the TriValve registry. Eur J Heart Fail 2023;25:2243-51. [Crossref] [PubMed]
18. Topilsky Y, Maltais S, Medina Inojosa J, Oguz D, Michelena H, Maalouf J, Mahoney DW, Enriquez-Sarano M. Burden of Tricuspid Regurgitation in Patients Diagnosed in the Community Setting. JACC Cardiovasc Imaging 2019;12:433-42. [Crossref] [PubMed]
19. Mehr M, Taramasso M, Besler C, Ruf T, Connelly KA, Weber M, et al. 1-Year Outcomes After Edge-to-Edge Valve Repair for Symptomatic Tricuspid Regurgitation: Results From the TriValve Registry. JACC Cardiovasc Interv 2019;12:1451-61. [Crossref] [PubMed]
20. Fam NP, Braun D, von Bardeleben RS, Nabauer M, Ruf T, Connelly KA, Ho E, Thiele H, Lurz P, Weber M, Nickenig G, Narang A, Davidson CJ, Hausleiter J. Compassionate Use of the PASCAL Transcatheter Valve Repair System for Severe Tricuspid Regurgitation: A Multicenter, Observational, First-in-Human Experience. JACC Cardiovasc Interv 2019;12:2488-95. [Crossref] [PubMed]
21. Anderson A, Hausleiter J, von Bardeleben RS, Schaefer U, Kuck K-H, Vahanian A, Juliard J-M, Latib A, Baldus S, Maisano F, Nickenig G. One-Year Outcomes of the TRI-REPAIR Study Assessing Cardioband Tricuspid Valve Reconstruction System for Patients with Functional Tricuspid Regurgitation. Journal of Cardiac Failure 2019;25:S11.
22. Kresoja KP, Rommel KP, Lücke C, Unterhuber M, Besler C, von Roeder M, Schöber AR, Noack T, Gutberlet M, Thiele H, Lurz P. Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation. JACC Cardiovasc Interv 2021;14:1551-61. [Crossref] [PubMed]
23. Anastasiou V, Bazmpani MA, Daios S, Moysidis DV, Zegkos T, Didagelos M, Karamitsos T, Toutouzas K, Ziakas A, Kamperidis V. Unmet Needs in the Assessment of Right Ventricular Function for Severe Tricuspid Regurgitation. Diagnostics (Basel) 2023;13:2885. [Crossref] [PubMed]
24. Webb JG, Chuang AM, Meier D, von Bardeleben RS, Kodali SK, Smith RL, et al. Transcatheter Tricuspid Valve Replacement With the EVOQUE System: 1-Year Outcomes of a Multicenter, First-in-Human Experience. JACC Cardiovasc Interv 2022;15:481-91. [Crossref] [PubMed]
25. Portnoy SG, Rudski LG. Echocardiographic evaluation of the right ventricle: a 2014 perspective. Curr Cardiol Rep 2015;17:21. [Crossref] [PubMed]
26. Dershowitz L, Lawlor MK, Hamid N, Kampaktsis P, Ning Y, Vahl TP, Nazif T, Khalique O, Ng V, Kurlansky P, Leon M, Hahn R, Kodali S, George I. Right ventricular remodeling and clinical outcomes following transcatheter tricuspid valve intervention. Catheter Cardiovasc Interv 2024;103:367-75. [Crossref] [PubMed]
27. Mao Y, Li L, Liu Y, Zhai M, Ma Y, Xu C, Jin P, Yang J. Safety, efficacy, and clinical outcomes of transcatheter tricuspid valve replacement: One-year follow-up. Front Cardiovasc Med 2022;9:1019813. [Crossref] [PubMed]
28. Ning XP, An Z, Qiao F, Cai CL, Han L, Song ZG, Li BL, Zhou GW, Wang J, Xu ZY, Lu FL. Safety and efficacy of transcatheter tricuspid valve replacement with LuX-Valve in patients with severe tricuspid regurgitation. Zhonghua Xin Xue Guan Bing Za Zhi 2021;49:455-60. [Crossref] [PubMed]
29. Kodali S, Hahn RT, George I, Davidson CJ, Narang A, Zahr F, et al. Transfemoral Tricuspid Valve Replacement in Patients With Tricuspid Regurgitation: TRISCEND Study 30-Day Results. JACC Cardiovasc Interv 2022;15:471-80. [Crossref] [PubMed]
30. Fam NP, von Bardeleben RS, Hensey M, Kodali SK, Smith RL, Hausleiter J, et al. Transfemoral Transcatheter Tricuspid Valve Replacement With the EVOQUE System: A Multicenter, Observational, First-in-Human Experience. JACC Cardiovasc Interv 2021;14:501-11. [Crossref] [PubMed]
31. Hahn RT, Kodali S, Fam N, Bapat V, Bartus K, Rodés-Cabau J, et al. Early Multinational Experience of Transcatheter Tricuspid Valve Replacement for Treating Severe Tricuspid Regurgitation. JACC Cardiovasc Interv 2020;13:2482-93. [Crossref] [PubMed]