Objectives:Transcatheter aortic valve implantation (TAVI) is an established therapy option for treatment of severe aortic valve stenosis (AS), particularly in patients with previous cardiac surgery. However, limited data exist regarding TAVI in patients after previous mitral valve repair or replacement (MVR). The aim of this study was to analyze outcomes of TAVI in patients with previous MVR and reveal possible interactions of transcatheter heart valves (THV) with mitral rings or prostheses.

Methods: Between 01/2010 and 07/2020, 29 patients at very high risk (58% female; mean age 76.2±9.1 years; Society of Thoracic Surgeons (STS) / logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) II of 10.2±4.1% / 14.6±7.6%) underwent TAVI after previous MVR. THV were implanted 12.8±7.4 years after mitral valve surgery. Previous MVR were performed as mechanical or biological mitral valve replacement or mitral valve repair in 44.8% (13/29), 20.8% (6/29) and 34.4% (10/29), respectively. Preprocedural multislice computed tomography (MSCT) analysis included analysis of the aortic to mitral annulus angle and the mitral prothesis/ring to aortic annulus distance. Acute procedural and early clinical outcomes were analyzed in accordance with standardized VARC-2 definitions.

Results: Preoperative MSCT revealed an aortic-mitral angle of 52.5±8.9° and a mitral prothesis/ring to aortic annulus distance of 8.5±0.9 mm. Implantation of THV was conducted via transfemoral (18/29, 62.2%), transapical (10/29, 34.4%) or transaxillary (1/29, 3.4%) access. Pre-/postballooning was performed in 68.9% (20/29) / 34.4% (10/29).

VARC-2 device success and early safety were 89.7% (26/29) and 86.2% (25/29), respectively. In two patients with a mitral annuloplasty ring, sequential THV implantation was required for malpositioning and in one patient with a preexisting mechanical mitral prothesis dislocation THV occurred. Notably, MSCT analysis of these three procedures revealed an aortic-mitral angle of > 60°. Overall 30-day mortality was 6.9% (2/29) due to myocardial ischaemia and mesenteric infarction. Bleeding complications and permanent pacemaker implantation were observed in 17.3% (5/29) and 13.8% (4/29) respectively. Acute kidney injury and stroke occurred in 10.3% (3/29) and 0% (0/29).  At 30-day follow-up, 96.6% of patients (28/29) had paravalvular leakage < moderate, transvalvular gradient was 8.2±4.2.

Conclusions: Results of this single center patient cohort at particular high-risk suggest that TAVI after MVR is technically feasible with acceptable early clinical and hemodynamic outcomes. However, the documented cases of malpositioning/dislocation suggest possible interactions of THV and preexisting mitral valve rings and prostheses, especially in patients with an aortic annulus to mitral annulus angle ˃60°. These findings should be considered during procedural planning and have to be confirmed in larger patient cohorts. Limitation of our results with regard to limited patient numbers over a long period of time call for a multi-centric analysis.