Cardiac Computed Tomography Screening for Tricuspid Transcatheter Annuloplasty Implantation

Tricuspid regurgitation is currently experiencing increased interest by interventional cardiologists because of the evolving treatment options.¹ Besides transcatheter edge-to-edge repair devices, transcatheter annuloplasty by implantation of a Cardioband (Edwards Lifesciences, Irvin, CA) is one of the few implants, which has already received “Conformité Européenne” certification and is therefore commercially available. The procedure itself is complex and is conducted by implantation of up to 17 anchors around the tricuspid annulus, warranting profound preprocedural assessment, including cardiac computed tomography angiography (CCTA) right-heart catheterization and echocardiography. For its part, CCTA allows the evaluation of structural and dimensional characteristics of the tricuspid annulus, the proximity of coronary vessels, the insertion and expected angulation of the catheter from the inferior vena cava into the right atrium, as well as its position to the tricuspid annulus, and provides the angulations for fluoroscopy at implantation. This screening is done in close collaboration with the distributing company, yet hardly any data regarding its outcomes is found in the literature.

We analyzed 58 consecutive symptomatic patients with severe tricuspid regurgitation and annular dilatation who underwent CCTA screening for Cardioband between July 2021 and June 2023. The presented analysis was part of an observational single-center study and was approved by an institutional review committee (Ethics Committee of Charité - Universitätsmedizin Berlin). The data that support the findings of this study are available from the corresponding author upon reasonable request. Each patient underwent ECG-gated whole-cycle CCTA by using a 320-detector-CT-scanner (Aquilion PRISM; Canon Medical Systems, Otawara, Japan) and the injection of 60 mL of iodinated contrast media (Imeron 400 MCT; Bracco, Konstanz, Germany). Image analysis for preprocedural screening was performed with 3mensio Structural Heart (3mensio Medical Imaging, Bilthoven, the Netherlands). Single anchor proximity to a coronary vessel was defined as a distance of <7 mm, whereas coronary proximity was determined whenever ≥3 consecutive anchors fell below that value. Categorical variables are described as numbers and percentages. Figures were designed with GraphPad PRISM, version 5 (GraphPad Software, Inc, La Jolla, CA) and PowerPoint 2016 (Microsoft Corporation, Redmond, WA).

Overall, screening success was observed in 34 (58.6%) patients, whereas 24 (41.4%) patients were deemed to be screening failures (Figure A). Major difficulties observed during screening were coronary proximity (n=47, 81.0%), impaired image quality (n=4, 6.9%; 1 mitral annuloplasty ring, 2 transcatheter aortic valve implants, and 1 atrial septal occluder), the presence of cardiac implantable electronic device leads with or without leaflet impingement (n=12, 20.7%), annulus dimensions with the potential of insufficient coverage by the device (n=11, 19.0%), and inferior vena cava insertion with expected limited catheter mobility (n=6, 10.3%). Although coronary proximity was detected in about 4 of 5 patients, it only led to screening failure in 21 (36.2%) patients given the inability to cross the coronary vessel and position the anchor safely. Similarly, cardiac implantable electronic device leads with or without leaflet impingement were present in 12 (20.7%) patients but resulted in only 2 (3.4%) screening failures (severe impingement, which precluded procedural success). Other features that have led to screening failure are inadequate annulus coverage (n=9, 15.5%; beyond tolerance with the longest device) and inferior vena cava insertion (n=2, 3.4%). Importantly, 10 (17.2%) patients displayed 2 reasons for screening failure (eg, coronary proximity and insufficient annulus coverage). Proximity to the coronary artery was mostly found in the posterior region of the tricuspid annulus (n=46, 79.3%), whereas the lateral (n=21, 36.2%) and anterior regions (n=8, 13.8%) were less frequently affected. Individual assessments of each anchor’s coronary proximity (Figure B) showed similar results being most prevalent at anchors 11 and 12 (n=43, 74.1%). Although coronary proximity could be due to either the right coronary artery or a dominant left circumflex artery, all instances were exclusively due to right coronary artery proximity in our cohort (as shown in Figure C and D).

Figure.

Cardiac computed tomography screening. A, Pie chart describing potential reasons for screening failure. B, Histogram yielding the frequency of anchors with coronary artery proximity. C (typical right coronary proximity) and D (no coronary proximity in left dominant patients found) are exemplary cases of analyzed cohort. CIED indicates cardiac implantable electronic device; LAO, left anterior oblique; and LCX, left circumflex artery.

This is the first analysis presenting the results of CCTA screening for interventional tricuspid annuloplasty. It stands as an addition to the TriSelect trial, which investigated patients for their echocardiographic and clinical suitability (58.1% accepted for tricuspid intervention).² Despite adequate screening success and recently published studies describing equal procedural effects in atrial and ventricular functional TR, Cardioband remains a selective therapy concept.³ Unlike newer concepts, it does not carry the potential of an “all-comer device.”⁴ CCTA provides critical insights in screening for transcatheter annuloplasty, which is also required before orthotopic and heterotopic transcatheter tricuspid valve replacement.

In conclusion, screening success was 58.6% in our cohort. Coronary proximity is a very common feature (found in about 4 of 5 patients) and most often found in the posterior region, yet frequently acceptable due to adequate possibilities to cross the vessel. Other reasons for screening failure include leaflet impingement by a cardiac implantable electronic device lead, inadequate annulus coverage, and displaced inferior vena cava insertion. Importantly, the presented analysis only relates to the device by 1 vendor.

ARTICLE INFORMATION

Sources of Funding

None.

Disclosures

Dr Barbieri declares research grant support from Abbott Laboratories and Boston Scientific, speaker honoraria from Edwards Lifesciences, and consulting fees from Boston Scientific. Dr Dreger reports research support from Abbott Laboratories and speaker honoraria from Abbott Laboratories and Edwards Lifesciences. The other authors report no conflicts.