Treatment of Tricuspid Regurgitation With the FORMA Repair System

PERSPECTIVE published: 15 October 2018 doi: 10.3389/fcvm.2018.00140 Treatment of Tricuspid Regurgitation With the FORMA Repair System Gidon Y. Perlman 1* and Danny Dvir 2 1 Hadassah Medical Center, Jerusalem, Israel, 2 Cardiology Department, University of Washington, Seattle, WA, United States Background: Tricuspid regurgitation (TR) is common and undertreated as the risk of surgery is high in this patient population. Transcatheter devices offer treatment with a lower procedural risk. The FORMA Tricuspid Valve Therapy system (Edwards Lifesciences) will be reviewed here. Device Description: The system combines a spacer placed in the regurgitant orifice and a rail, over which the spacer is delivered, that is anchored to the endocardial surface of the RV. The spacer provides a surface for leaflet coaptation. Edited by: Fabien Praz, Universitätsspital Bern, Switzerland Reviewed by: Antonio Mangieri, San Raffaele Hospital (IRCCS), Italy Paolo Denti, San Raffaele Hospital (IRCCS), Italy Michael Chrissoheris, Hygeia Hospital, Greece *Correspondence: Gidon Y. Perlman Specialty section: This article was submitted to Structural Interventional Cardiology, a section of the journal Frontiers in Cardiovascular Medicine Received: 25 July 2018 Accepted: 19 September 2018 Published: 15 October 2018 Citation: Perlman GY and Dvir D (2018) Treatment of Tricuspid Regurgitation With the FORMA Repair System. Front. Cardiovasc. Med. 5:140. doi: 10.3389/fcvm.2018.00140 Outcomes: Eighteen compassionate care patients and 29 patients included in the US EFS trial are reviewed. Patients were elderly (76 years) and high risk (Euroscore 2 was 9.0 and 8.1%, respectively). There were 2 procedural failures in both groups. Mortality at 30 days was 0% in the compassionate group and 7% in the EFS trial. TR was reduced in both groups; 2D/3D EROA 2.1 ± 1.8 to 1.1 ± 0.9 cm2 in the EFS trial and vena contracta width 12.1 ± 3.3 to 7.1 ± 2.2 mm. Symptomatic improvement was seen in both groups; the proportion of patients in NYHA class III/IV decreased from 84 to 28% at 30 days in the EFS group, and from 94 to 21% at 1 year, in the compassionate group. Conclusions: Reduction of TR with FORMA system is feasible and sustained. Despite residual TR post-procedure, the significant relative reduction in TR severity contributes to substantial clinical improvements in patients with a FORMA device in place. Keywords: tricuspid regurgitation (TR), transcatheter, effective regurgitant orifice, FORMA, right ventricle (RV) INTRODUCTION Severe tricuspid regurgitation (TR) is a common and under-treated valvular pathology associated with increased morbidity and mortality (1–4). Recent data has shown that despite advances in surgical care over the years, surgery for isolated TR is rarely performed and operative mortality is still discouraging (5, 6). Transcatheter therapies for TR have the potential advantage over surgery of reduced procedural risks, mainly due to reduced bleeding (from venous access sites) and reduced thoracic tissue damage, enabling easier recovery. Current transcatheter devices treat TR by improving leaflet coaptation or by modulating the annular geometry (7–12). The tricuspid valve apparatus is adjacent to both the right coronary artery (RCA) and the AV node; furthermore, the right atrium (RA) and right ventricle (RV) are thin walled and prone to injury from transcatheter devices. Performing percutaneous procedures for TR requires careful maneuvering around these structures to avoid injury, which has been reported after surgery (13) and with transcatheter devices (10, 14). Patients with severe TR tend to have important co-morbidities. TR is associated with renal dysfunction that is often exacerbated by diuretics and hepatic congestion caused by TR can Frontiers in Cardiovascular Medicine | www.frontiersin.org 1 October 2018 | Volume 5 | Article 140 Perlman and Dvir FORMA for TR FIGURE 1 | Schematic representation of the FORMA system. lead to liver dysfunction. Atrial fibrillation is strongly associated with TR and patients often require anticoagulation for prevention of thromboembolic events. These conditions combine to put patients with severe TR at an increased risk of bleeding. Furthermore, chronic edema of the lower extremities which is the hallmark of right sided failure and contribute to significant impairment of ambulation. Taken together, the comorbid conditions of patients with severe TR can greatly impact the recovery and outcomes of patients after transcatheter TR repair. The FORMA Tricuspid Valve Therapy System (Edwards Lifesciences, Irvine, CA) is a transcatheter device for treatment of patients with severe secondary TR. This review will present accumulating data on short and mid-term results of patients treated with this device. FIGURE 2 | Transthoracic echocardiography showing the FORMA spacer (*) positioned in the tricuspid valve. TABLE 1 | Baseline characteristics. Characteristic Age, years Female sex–No. (%) Serum creatinine-mg/dl Compassionate care (n = 18) EFS trial (n = 29) 76 ± 9.7 75.9 ± 8.2 13 (72) 19 (66) 1.5 ± 0.8 1.3 ± 0.4 NYHA functional class III/IV–No. (%) 17 (94) 25 (86) Device Description EuroSCORE II 9 ± 5.7 8.1 ± 5.3 The Edwards FORMATM system combines a spacer unit placed in the regurgitant orifice and a rail, over which the spacer is delivered, that is anchored to the endocardial surface of the RV (Figure 1). The spacer is a foam-filled polymer balloon that is round and tubular shaped, it is 42 mm long and has diameters of 12, 15, and 18 mm. When the spacer is positioned across the tricuspid annulus the native leaflets have a new surface for coaptation, thereby improving TR. Insertion of the spacer across the valve is done over a rail; the rail extends from the left subclavian vein to the RV apex. A nitinol anchor with 6 curved prongs is designed to grasp the RV myocardium without exiting into the pericardial space. A 20F or 24F sheath is required for implantation of the FORMA system, through the sheath a dedicated delivery system is used to position the anchor and rail in the correct position. The delivery system can be flexed to navigate the anchor through valve and RV trabeculations. Close to the tip of the delivery system is a large balloon which is inflated prior to crossing the STS (for mitral valve replacement) Frontiers in Cardiovascular Medicine | www.frontiersin.org 6 min walk test-meters* Kansas City cardiomyopathy questionnaire* NA 9.1 ± 6.8 256 ± 103 183 ± 96 63 ± 20 39 ± 22 Coexisting conditions-No. (%) Atrial fibrillation 16 (89) 24 (83) Coronary artery disease 10 (56) 16 (55) Prior CABG 7 (22) 9 (31) Previous valvular intervention 9 (50) 14 (48) Stroke/TIA 2 (11) 11 (38) Chronic lung disease 5 (28) 7 (24) Liver disease 1 (6) 9 (31) Pacemaker/defibrillator 3 (17) 7 (24) Values are mean ± SD or n (%).*EFS data is for patients with paired data. CABG, coronary artery bypass grafting; TIA, transie (...truncated)