The 1-year survival rate of patients who underwent transcatheter tricuspid valve (TTV) repair to treat severe, symptomatic tricuspid regurgitation (TR) dropped as the grade of residual TR at discharge increased, according to a new registry analysis. Furthermore, dividing patients with residual moderate TR into two groups, mild-to-moderate and moderate-to-severe, as is typically done with mitral regurgitation (MR), showed a significantly lower survival rate in the moderate-to-severe TR patients. Julien Dreyfus, MD, PhD, of Centre Cardiologique du Nord, Saint-Denis, France, presented these findings during a late-breaking trials session Thursday at EuroPCR in Paris. A manuscript reporting the results was simultaneously published online in JACC: Cardiovascular Interventions. Study details While TTV repair has a well-established safety profile in treating TR, residual TR remains a concern. Therefore, the investigators assessed the impact on survival of residual TR severity, which is seen in as many as a third of patients after TTV repair. If procedural success after TTV repair is defined as a reduction of TR grade to 2+ or less at discharge, 65% of patients in TRIGISTRY who underwent TTV repair met this goal. In patients whose procedure was successful, there was a significant improvement in 2-year survival in TTV repair patients compared to medical therapy alone in the low to intermediate TRISCORE category, previously published TRIGISTRY registry results show. However, this same publication showed that there was no survival benefit for TTV repair compared to medical therapy if the TTV repair was not successful. Currently, TR is typically graded on three levels: mild, moderate and severe, whereas MR is graded on four levels: mild, mild-to-moderate, moderate-to-severe, and severe. For this analysis, the investigators used both the three- and four-grade schemes to assess TR. TRIGISTRY includes 2,413 patients who were treated for severe, isolated, functional TR on the native valve and had an available TRISCORE. Of these, 1,217 patients were treated with medical therapy, 551 underwent isolated tricuspid valve surgery, and 645 underwent TTV repair. Of the TTV repair patients, 509 underwent edge-to-edge repair with MitraClip (Abbott), TriClip (Abbott) or PASCAL (Edwards Lifesciences), and 136 underwent annuloplasty with Cardioband (Edwards Lifesciences) or other devices. The current analysis included 613 patients from the TTV repair cohort who were discharged alive and whose residual TR was assessed at discharge. At baseline, the patients’ mean age was 78±8 years (88% were 70 or older), 60% were female, 29% had a permanent pacemaker, 33% had previously undergone left-sided valve intervention, 86% were in New York Heart Association (NYHA) functional class III or IV, 63% showed signs of right-sided heart failure, 86% had atrial fibrillation, and the cohort had a median TRISCORE of 5% (interquartile range: 4-6). Three-grade vs. four-grade TR At discharge, using the three-grade scheme, 15% of patients had severe TR, 52% had moderate TR, and 33% had none or mild TR. Looking at the baseline characteristics of these subgroups, several differences emerge. While the mean age was not significantly different, there was a borderline significantly higher percentage of patients ages 70 or older who had none or mild TR at discharge (93%) compared to those with moderate (87%) or severe (85%) TR (p=0.05). Also, patients with none/mild TR and moderate had a significantly lower mean creatinine level (none/mild 115 µmmol/L) than those with moderate or severe TR (moderate 128 µmmol/L, severe 131 µmmol/L; p=0.03). The mean tricuspid annulus diameter in an apical four-chamber view was also smaller in patients with none/mild TR at discharge (44 mm) compared to moderate (46 mm) or severe (48 mm; p=0.0003) and less moderate or severe right ventricular dilatation and dysfunction. Finally, the mean systolic pulmonary artery pressure of patients with none/mild and moderate TR was significantly higher (45 mmHg in both) than in those with severe TR (39 mmHg; p=0.02). Other significant differences include a lower median daily dose of loop diuretics (none/mild 40 mg, moderate 60 mg, severe 80 mg; p=0.013) and daily dose 125 mg or greater (none/mild 10%, moderate 23%, severe 23%; p<0.001). At 1 year, patients who had none/mild residual TR at discharge had an 85% survival rate, those with moderate TR had a 70% survival rate (p=0.25 for none/mild vs. moderate), and those with severe TR had a 44% survival rate (p=0.04 for moderate vs. severe). Looking at the four-grade scheme, the 52% of patients with moderate TR in the three-grade scheme were divided into mild-to-moderate (33% of the study population) and moderate-to-severe (19%). The four-grade scheme also revealed several differences among patients at baseline. At 1 year, there was no significant difference in survival between patients with mild TR at discharge (85%) and those with mild-to-moderate TR (80%; p=0.67). However, there was a significant difference between those with mild-to-moderate TR (80%) and those with moderate-to-severe TR (55%; p=0.006), and there was no significant difference between those with moderate-to-severe TR (55%) and those with severe TR (44%; p=0.96). Dreyfus concluded that survival rates decreased as the grade of residual TR after TTV repair increased. The four-grade scheme, dividing the moderate TR patients into two groups, showed that the moderate grade itself shows these patients to be “heterogeneous,” and that this subdivided grade “refined the prognosis of these patients.” The results, he said, support the use of the more granular four-grade scheme in evaluating TR and “highlight the importance of achieving optimal procedural results, defined as a mild-to-moderate or lower residual TR instead of a moderate or lower residual TR grade.” Dreyfus added that these findings “deserve further confirmation in other studies and, critically, in randomized controlled studies.” Need to Reduce Residual TR In an accompanying editorial, Marta Sitges, MD, PhD, of Hospital Clinic University of Barcelona, Spain, said, “These findings underscore the prognostic importance of effectively eliminating TR.” She added that the authors, led by Dreyfus, “merit recognition for their efforts to consolidate global experience, enhancing our understanding of this field.” She listed several limitations, including that the registry is observational and retrospective, which might not account for residual confounders, “especially in an elderly multimorbid population.” T grading was not assessed with an independent core laboratory but, rather, was site-reported. Sitges noted, however, that the results reported by Dreyfus and colleagues are consistent with those of studies that did use a centralized evaluation of residual TR. She also posed the question of whether TTV replacement might be better if the ultimate goal is eliminating residual TR, but then she noted that the durability of right-sided replacement valves might be hindered by functional stenosis, thrombosis and early valve deterioration, as shown by surgical replacement. Finally, she said, completing eliminating TR in patients with a failing, dilated right ventricle “remains unknown” and “could lead to afterload mismatch, which might be problematic.” “Clearly, no single solution fits all patients, but the encouraging news is the increasing availability of less invasive and safer treatment options, including orthotopic and heterotopic bioprostheses,” Sitges concluded. “Given the current evidence, our efforts should concentrate on repairing patients with TR before they reach an irreparable stage, aiming to achieve optimal results with mild residual TR at most.” Sources: Dreyfus J, Taramasso M, Kresoja K-P, et al. Prognostic Implications of Residual Tricuspid Regurgitation Grading After Transcatheter Tricuspid Valve Repair. JACC Cardiovasc Interv. 2024 May 16 (Article in press). Sitges M. Residual Tricuspid Regurgitation after Intervention: Less is More. JACC Cardiovasc Interv. 2024 May 16 (Article in press). Photo Credit: Screenshot by Jason Wermers/CRTonline.org Photo Caption: Julien Dreyfus, MD, PhD, discusses the results of an analysis of the TRIGISTRY registry during a late-breaking trials session Thursday at EuroPCR 2024.