Current Status of Catheter-based Mitral Valve Replacement.

PURPOSE OF REVIEW: Transcatheter mitral valve replacement (TMVR) has been developed to address the need for an alternative therapeutic option to surgery in patients suffering from severe mitral regurgitation who are at high surgical risk. The present review illustrated the state-of-the-art of catheter-based mitral valve replacement evaluating technical characteristics and early clinical experience of different devices to outline prospects and challenges of TMVR. RECENT FINDINGS: Several devices are currently under clinical assessment. Early experience has demonstrated high procedural success of TMVR. However, TMVR faces several possible hurdles such as left ventricular outflow tract obstruction (LVOTO) after prosthesis deployment, access site complications, and thrombotic risk requiring anticoagulatory therapy. Future studies should assess long-term prosthesis stability, optimal anticoagulation regime, and occurrence of paravalvular leakage. The development of smaller TMVR prostheses suitable for transseptal implantation could overcome bleeding complications. In perspective, TMVR may emerge to a clinically relevant therapeutic approach for patients with severe MR at high surgical risk.

Early Experience With Transcatheter Mitral Valve Replacement: A Systematic Review.

Background Transcatheter mitral valve replacement (TMVR) has emerged as an alternative therapeutic option for the treatment of severe mitral regurgitation in patients with prohibitive or high surgical risk. The aim of this systematic review is to evaluate the clinical procedural characteristics and outcomes associated with the early TMVR experience. Methods and Results Published studies and international conference presentations reporting data on TMVR systems were identified. Only records including clinical characteristics, procedural results, and 30-day and midterm outcomes were analyzed. A total of 16 publications describing 308 patients were analyzed. Most patients (65.9%) were men, with a mean age of 75 years (range: 69-81 years) and Society for Thoracic Surgery Predicted Risk of Mortality score of 7.7% (range: 6.1-8.6%). The etiology of mitral regurgitation was predominantly secondary or mixed (87.1%), and 81.5% of the patients were in New York Heart Association class III or IV. A transapical approach was used in 81.5% of patients, and overall technical success was high (91.7%). Postprocedural mean transmitral gradient was 3.5 mm Hg (range: 3-5.5 mm Hg), and only 4 cases (1.5%) presented residual moderate to severe mitral regurgitation. Procedural and all-cause 30-day mortality were 4.6% and 13.6%, respectively. Left ventricular outflow obstruction and conversion to open heart surgery were reported in 0.3% and 4% of patients, respectively. All-cause and cardiovascular-related mortality rates were 27.6% and 23.3%, respectively, after a mean follow-up of 10 (range: 3 to 24) months. Conclusions TMVR was a feasible, less invasive alternative for treating severe mitral regurgitation in patients with high or prohibitive surgical risk. TMVR was associated with a high rate of successful valve implantation and excellent hemodynamic results. However, periprocedural complications and all-cause mortality were relatively high.

Transcatheter mitral valve intervention: an emerging treatment for mitral regurgitation.

Mitral regurgitation (MR) is a valvular heart disease associated with significant morbidity and mortality. Transcatheter mitral valve intervention (TMVI) repairs or replaces the mitral valve through small arterial and venous entry sites and so avoids risks associated with open heart surgery. Transcatheter devices targeting components of the mitral apparatus are being developed to repair or replace it. Numerous challenges remain including developing more adaptable devices and correction of multiple components of the mitral annulus to attain durable results. The mitral valve apparatus is a complex structure and understanding of the mechanisms of MR is essential in the development of TMVI. There will likely be a complementary role between surgery and TMVI in the near future.

Transcatheter Mitral Valve Replacement: Insights From Early Clinical Experience and Future Challenges.

Transcatheter mitral valve repair, particularly edge-to-edge leaflet repair, is a well-established alternative for patients with severe primary mitral regurgitation (MR) considered at high or prohibitive surgical risk. More recently, transcatheter mitral valve replacement (TMVR) has emerged as a potential therapeutic option for the treatment of severe MR. TMVR may offer some advantages over transcatheter repair by providing a more complete and reproducible MR reduction. Several devices are under preclinical and clinical evaluation, and the early experience with more than 100 patients has demonstrated the feasibility of TMVR. In this review, we describe the TMVR systems currently in development and the results obtained from early clinical experiences. We also discuss the main challenges in and future perspectives on this emerging field. Future studies with a much larger number of patients are needed to provide consistent safety and efficacy data on each of the TMVR systems.

Initial Experience of Transcatheter Mitral Valve Replacement With a Novel Transcatheter Mitral Valve: Procedural and 6-Month Follow-Up Results.

BACKGROUND: There are scarce data available on transcatheter mitral valve replacement (TMVR), and these have been limited to procedural results, with no follow-up status reported. OBJECTIVES: The goal of this study was to evaluate the feasibility, procedural results, and 6-month follow-up outcomes after TMVR with a mitral transcatheter heart valve (Fortis, Edwards Lifesciences, Irvine, California). METHODS: We report a series of 3 patients (mean age 71 ± 9 years, 2 men) who had TMVR under a compassionate clinical use program. All patients treated had functional mitral regurgitation (MR) secondary to ischemic cardiomyopathy (prior bypass surgery in all cases; left ventricular ejection fraction between 25% and 30%) and were considered to be at very high surgical risk (mean Society of Thoracic Surgeons score: 9.3). RESULTS: The procedure was performed through the transapical approach, and the valve was successfully implanted in all cases, with no major complications. At hospital discharge, echocardiographic evaluation revealed trace residual MR in 2 patients and no MR in 1 patient. The mean transvalvular mitral gradient was ≤4 mm Hg in all patients. At the 3-month follow-up, the valve function remained unchanged, and transesophageal echocardiography and computed tomography showed no structural failures. All patients had improvements in functional status, in exercise capacity as evaluated by 6-min walk test, and in quality of life. At 6-month follow-up, all patients remain alive, without hospital readmission for heart failure and with New York Heart Association functional class ≤II. CONCLUSIONS: TMVR with this valve is feasible and is associated with good outcomes. Optimal valve functional results were obtained acutely and were sustained at 6-month follow-up in all patients. Further studies with a larger number of patients and longer follow-up are warranted.