Single center experience with the balloon-expandable Myval transcatheter aortic valve system with the first 100 patients: 30-day and 1-year follow-up

The novel balloon-expandable Myval transcatheter heart valve: systematic review of aortic, mitral, tricuspid and pulmonary indications

INTRODUCTION AND OBJECTIVES

Myval technology represents the first balloon-expandable alternative since the Edwards system became commercially available. Despite certain controversies, its use has rapidly expanded. We aimed to gather all the available literature regarding its indications and outcomes.

METHODS

A comprehensive search of articles published between December 2016 and May 2024 was conducted using BioMedCentral, Google Scholar, and PubMed to evaluate the main outcomes of Myval for native aortic stenosis (AS) (meta-analysis) and off-label uses (systematic review).

RESULTS

A total of 151 studies were identified, and 74 were included in the analysis, covering aortic (n=51), mitral (n=9), tricuspid (n=6), and pulmonary (n=8) valve positions. A meta-analysis of studies on native AS demonstrated that Myval is safe and effective, with a 30-day mortality rate of 1.3%, good hemodynamic performance, low rates of pacemaker implantation (8.8%), and ≥ moderate paravalvular regurgitation (1.3%). Compared with other contemporary devices, Myval was competitive and associated with lower rates of pacemaker implantation. In a systematic review of off-label indications, Myval was also found to be safe and effective. In bicuspid AS, pure regurgitation, and aortic valve-in-valve procedures, success rates were 100%, 92%, and 100%, respectively, with pacemaker rates of 9.9%, 22.2%, and 3%, respectively. For mitral valve-in-valve/in-ring procedures, the success rate was 96.9%, while in tricuspid and pulmonary positions, small case series reported 100% success rates for both, with minimal procedural complications.

CONCLUSIONS

Myval technology is safe and effective for the treatment of native valvular disease and dysfunctional prostheses or rings in all heart valve positions, although larger scale studies are warranted.

Performance of the Mammoth Balloon Catheter in Patients with Severe Aortic Valve Stenosis Undergoing Percutaneous Treatment

Background: Balloon aortic valvuloplasty (BAV) is currently used as pre-treatment for patients undergoing trans-catheter aortic valve replacement (TAVR) as well as a stand-alone option for subjects with significant contraindications to TAVR. Mammoth is a newly available non-compliant balloon catheter (BC) included in the balloon-expandable Myval THV system (Meril Life Sciences Pvt. Ltd., India). As limited data on the performance of this BC are available, we here report the results following its use for BAV as pre-dilatation during TAVR or as a stand-alone procedure. Methods: A retrospective, single-center cohort analysis was performed on patients with severe aortic valve stenosis (AS) treated with the Mammoth BC at IRCCS Ospedale Galeazzi Sant'Ambrogio, Milan, Italy. The primary endpoint was technical success defined as successful Mammoth BC advancement across the AS followed by its full and homogeneous inflation without major complications such as aortic root/left ventricular outflow tract injury and/or stroke. Results: A total of 121 patients were treated by BAV with Mammoth BC during the study period. Among these, 105 patients underwent BAV pre-dilatation before TAVR while 16 patients underwent a stand-alone BAV procedure. Mammoth BC was delivered and successfully inflated at the target site in all of the 121 cases without BC-related complications (100% technical success). However, in the BAV "stand-alone group", three patients required two different balloon sizes while in nine patients multiple rounds (two to three) of balloon inflation were needed to significantly lower the transvalvular gradient. No cases of aortic root injury or massive aortic regurgitation due to Mammoth BC-related aortic leaflet injury were reported while one major stroke occurred late after TAVR. No intra-procedural deaths occurred nor bleeding (BARC 3-4) or major vascular complication. Conclusions: Mammoth BC use in patients with severe AS proved safe and effective, either before TAVR or as a stand-alone procedure, expanding the range of available tools for structural operators.

A novel balloon-expandable transcatheter aortic valve bioprosthesis: Myval and Myval Octacor

INTRODUCTION

Over the past two decades, transcatheter aortic valve replacement (TAVR) has expanded its application across all surgical risk levels, including low-risk patients, where, due to longer life expectancy, reducing common pitfalls of TAVR is essential. To address these needs, many technological advancements have been developed. Myval and the new generation Myval Octacor (Meril Life Sciences Pvt. Ltd) are novel balloon-expandable (BE) transcatheter heart valve (THV) systems designed for the treatment of severe aortic stenosis.

AREAS COVERED

This review aims to illustrate the design features of these novel THVs and the main evidence from available studies. Furthermore, we provide evidence of these THVs' performance in challenging scenarios such as extra-large aortic annuli, bicuspid aortic valves, and valve-in-valve/valve-in-ring procedures.

EXPERT OPINION

Myval and Myval Octacor have demonstrated comparable early safety and clinical efficacy to the leading contemporary THVs, exhibiting remarkably low rates of moderate to severe paravalvular leak (PVL) and permanent pacemaker implantation (PPI). The wide range of sizes offered by the Myval family may minimize the risk of under-/oversizing, potentially explaining the lower rates of the aforementioned phenomena. Moreover, the presence of both internal skirt and external reinforced cuff may also explain the low rate of moderate to severe PVL.

Single-Center Experience with the Balloon-Expandable Myval Transcatheter Aortic Valve System in Patients with Bicuspid Anatomy: Procedural and 30-Day Follow-Up

Aims: To report our single-center data regarding the initial 52 consecutive patients with a bicuspid aortic valve who underwent a Transcatheter Aortic Valve Implantation (TAVI) procedure using the new balloon-expandable MYVAL system. The focus is on reporting procedural details and outcomes over the 30-day postoperative period. Methods: From December 2019 to July 2023, 52 consecutive patients underwent a TAVI procedure with bicuspid anatomy. All patients had moderate to-high surgical risk or were unsuitable for surgical aortic valve replacement based on the Heart Team's decision. Outcomes were analyzed according to the VARC-2 criteria. The results of bicuspid patients were compared to patients with tricuspid anatomy in the overall study group, and further analysis involved a comparison between 52 pairs after propensity score matching. The device performance was evaluated using transthoracic echocardiography. Data collection was allowed by the Local Ethical Committee. Results: The mean age was 71 ± 7.1 years, and 65.4% were male. The mean Euroscore II and STS score were 3.3 ± 3.2 and 5.2 ± 3.3, respectively. Baseline characteristics and echocardiographic parameters were well balanced even in the unmatched comparison. Procedures were significantly longer in the bicuspid group and resulted in a significantly higher ARI index. All relevant anatomic dimensions based on the CT scans were significantly higher in bicuspid anatomy, including a higher implantation angulation, a higher rate of horizontal aorta and a higher proportion of patients with aortopathy. In the unmatched bicuspid vs. tricuspid comparison, postprocedural outcomes were as follows: in-hospital mortality 0% vs. 1.4% (p = 0.394), device success 100% vs. 99.1% (p = 0.487), TIA 1.9% vs. 0% (p = 0.041), stroke 1.9% vs. 0.9% (p = 0.537), major vascular complication 3.8% vs. 2.3% (p = 0.530), permanent pacemaker implantation 34% vs. 30.4% (p = 0.429), and cardiac tamponade 0% vs. 0.5% (p = 0.624). In the propensity-matched bicuspid vs. tricuspid comparison, postprocedural outcomes were as follows: in-hospital mortality 0% vs. 0%, device success 100% vs. 100%, TIA 1.9% vs. 0% (p = 0.315), stroke 1.9% vs. 0.9% (p = 0.315), major vascular complication 3.8% vs. 0% (p = 0.475), permanent pacemaker implantation 34% vs. 24% (p = 0.274), and cardiac tamponade 0% vs. 0%. There was no annular rupture nor need for second valve or severe aortic regurgitation in both the unmatched and matched comparison. The peak and mean aortic gradients did not differ at discharge and at 30-day follow-up between the two groups regardless of whether the comparison was unmatched or matched. There were no paravalvular leakages (moderate or above) in the bicuspid patients. Intermediate and extra sizes of the Myval THV system used a significantly higher proportion in bicuspid anatomy with a significantly higher oversize percentage in tricuspid anatomy. Conclusions: The TAVI procedure using the Myval THV system in patients with significant aortic stenosis and bicuspid aortic valve anatomy is safe and effective. Hemodynamic parameters do not differ between tricuspid and bicuspid patients. However, the permanent pacemaker implantation rate is higher than expected; its relevance on long-term survival is controversial.