Transcatheter valve in valve implantation for failed mitral and tricuspid bioprosthesis.

OBJECTIVE: We report our experience with the transapical transcatheter "Valve in valve" implantation (T-VIV) in patients with a failed mitral or tricuspid bioprosthesis; we briefly review the pertinent literature, and discuss some technical aspects of this procedure. BACKGROUND: Redo valve surgery for failure of a mitral or tricuspid bioprosthesis might become extremely challenging, both because of the patients' condition, which is frequently poor, and for the technical aspects of the operation itself, that can be very demanding. T-VIV has been widely employed with good results for the treatment of aortic bioprosthesis failure, and could represent an attractive option in this setting. METHODS: Four patients with multiple comorbidities (age: 63-83 years; logistic Euroscore: 37.2-81.5) underwent T-VIV at our institution for failure of a mitral [3] or tricuspid [1] bioprosthesis. A 26 mm Sapien valve was used in all cases. All the mitral procedures were performed via a transapical approach. The tricuspid procedure was performed via a transjugular approach. RESULTS: The first mitral procedure was complicated by the splaying of the xenograft stents and embolization of the valve. The procedure was converted to conventional surgery, and the patient died on postoperative day 1. In the subsequent procedures, the valve was positioned more atrially, and was fixed to the malfunctioning xenograft sewing ring. All subsequent procedures were successful, all patients were discharged home and were alive and well at follow-up. CONCLUSIONS: The results of T-VIV procedure in the mitral position have been suboptimal, and four of the sixteen patients reported to date died. However, all patients were extremely diseased, and some of the reported failures were related to amendable technical factors relative to the surgical access or to the valve deployment technique. With increasing experience, this procedure might become indicated as an alternative to conventional surgery in selected patients, encouraging increased use of bioprosthesis, and marking a pivotal change in the management of valvular disease.

Simultaneous Functional and Morphological Assessment of Left Atrial Appendage by 3D Virtual Models.

Purpose: The left atrial appendage (LAA) is responsible for thrombus formation in patients with atrial fibrillation. The evaluation of both LAA function and morphology is crucial for the patient characterization and the preprocedural planning of LAA closure intervention. Despite the availability of 3D imaging modalities, the current standard image analysis is based on manual delineation of the LAA contours on 2D views. Methods: In this study, a comprehensive approach based on a full 3D analysis of the tomographic dataset by surface extraction and processing (3D-S) is presented. The proposed method allows extracting functional and morphologic information in the entire cardiac cycle by minimalizing manual user interaction. The proposed methodology has been validated on ten computer tomography datasets. Results: The proposed 3D-S method was feasible in all cases. Reproducibility was improved with respect to the reference 2D manual procedure (2D-S) (coefficient of variation 2.9 vs. 4.1% for diastolic ostium area; 3.8 vs. 6.1% for systolic ostium area; 2.4 vs. 5.3% for diastolic LAA volume; 2.7 vs. 5.9% for systolic LAA volume; and 7.7 vs. 17.1% for LAA ejection fraction). No significant differences were found between 2D-S and 3D-S measurements. Conclusions: In this study, we introduced a fully 3D approach for LAA characterization, allowing the simultaneous assessment of LAA function and geometry. The proposed approach could be used to improve the patient selection and the best sizing of the device for LAA closure and to allow a patient-specific 3D printing.

Left atrial appendage occlusion in high-risk patients with non-valvular atrial fibrillation.

OBJECTIVE: Percutaneous left atrial appendage (LAA) occlusion has been developed as a viable option for stroke and thromboembolism prevention in patients with non-valvular atrial fibrillation (NVAF) and at high risk for cerebral cardioembolic events. Data on device implantation and long-term follow-up from large cohorts are limited. METHODS: 110 consecutive patients with NVAF and contraindications to oral anticoagulants (OACs) underwent LAA occlusion procedures and achieved a longer than 1 year follow-up. All patients were enrolled in a prospective registry. Procedures were performed using the Amplatzer Cardiac Plug or Amulet guided by fluoroscopy and intracardiac echocardiography. RESULTS: Mean age of the population was 77±6 years old; 68 were men. Atrial fibrillation was paroxysmal in 20%, persistent in 15.5% and permanent in 64.5% of cases, respectively. Mean CHA2DS2-VASc and HAS-BLED scores were 4.3±1.3 and 3.4±1, respectively. Technical success (successful deployment and implantation of device) was achieved in 100% of procedures. Procedural success (technical success without major procedure-related complications) was achieved in 96.4%, with a 3.6% rate of major procedural complications (three cases of pericardial tamponade requiring drainage and one case of major bleeding). Mean follow-up was 30±12 months (264 patient-years). Annual rates for ischaemic stroke and for other thromboembolic events were respectively 2.2% and 0%, and annual rate for major bleeding was 1.1%. CONCLUSIONS: Our data suggest LAA occlusion in high-risk patients with NVAF not suitable for OACs is feasible and associated with low complication rates as well as low rates of stroke and major bleeding at long-term follow-up.