Background Percutaneous repair for severe tricuspid regurgitation (TR) is emerging as a viable option, but patient selection is challenging and predetermined by comorbidities. Risk assessment before tricuspid valve (TV) procedures should discriminate high- and low-risk surgical patients, with the former being possible candidates for interventional therapy, if deemed inoperable. The latest guidelines even go so far as to distinguish between patients at high and prohibitive risk, in order to avoid procedural futility in the latter. Aim of the study This study evaluated one-year outcomes of transcatheter tricuspid valve repair (TTVR) in very sick inoperable patients at prohibitive risk, and explored the concept of risk-based therapeutic futility. Methods TTVR patients from our Pforzheim Tricuspid Valve Registry were prospectively assigned to prohibitive (PR) and high-risk (HR) subgroups, based on Society of Thoracic Surgeons (STS) Score, frailty indices, and major organ system compromise, as proposed by the current American guideline for valvular heart disease. Efficacy and safety outcomes were compared at baseline, 30 days, 6 and 12 months. 

The primary efficacy endpoint was a reduction in TR severity of at least one grade at 30 days, according to the 5-grade classification. Secondary endpoints assessed improvement in quality of life [New York Heart Association (NYHA) functional class and Kansas City Cardiomyopathy Questionnaire (KCCQ) score], exercise capacity during 6-minute walk test (6MWT), renal and hepatic function, but also right heart remodeling. Exclusion criteria included treatable left heart disease e.g., significant mitral regurgitation, and systolic pulmonary artery pressure >70mmHg. Results Forty individuals with high-grade TR (mean-age 81.9±4.9, 50% women), turned down for TV surgery by the Heart Team, underwent edge-to-edge TTVR with a TV specific device, and completed one-year follow-up between May 2021 and October 2022. Patients were highly symptomatic (NYHA III-IV 87.5%) despite diuretic therapy, and had advanced multiorgan disease (chronic kidney disease stage 3-5: 82.5%, liver vein congestion: 80%). Almost all (97.5%) suffered from atrial fibrillation, and 22.5% had pacemaker leads. The primary efficacy endpoint of at least one-grade TR reduction by 30 days was recorded in 92.5% of all patients, with no device related adverse events. In accordance with risk assessment definition, the two subgroups consisted of 23 PR (STS-Score 14.5±6.3%) and 17 HR (STS-Score 5.8±1.5%) patients. After 12 months, 74% of PR and 94% of HR patients were in NYHA class I/II. KCCQ-Score increased by 24.4±18.3 (p<0.001) vs 25.4±17.1 pts. and 6MWT by 81.8±76.6 (p<0.001) vs 106.5±73.9 meters (p<0.001). Multiorgan function improved in both groups [ΔGFR 7.2±12.5 (p=0.012) vs 2.1±10.1 ml/min/1,73m²  (p=0.418); ΔAST 6.7±8.1 (p<0.001) vs 7.2±22.2 U/L (p=0.205)]. Reverse cardiac remodeling was represented among others by increase in right ventricular systolic function [TAPSE Δ19% (p<0.001) vs 32% (p<0.001)], and decrease in right heart chambers size [RA index. volume Δ43% (p=0.005) vs 29% (p=0.004)]. Twelve-month mortality was 12.5%, with overall 10 hospitalizations for acute heart failure.

Conclusions

TR reduction significantly impacted quality of life, functional capacity, cardiac remodeling and multiorgan involvement, similarly in PR and HR patients. TTVR is feasible in very sick symptomatic patients, irrespective of predicted risk.