High pacing rates for management of aortic insufficiency after balloon aortic valvuloplasty or transcatheter aortic valve replacement

Balloon aortic valvuloplasty: current status and future prospects

INTRODUCTION

Balloon aortic valvuloplasty (BAV) improves hemodynamic and clinical status of patients with severe aortic stenosis (AS) for a limited period of 6-12 months. However, there is a high number of procedures performed worldwide and an upward trend over the last decades.

AREAS COVERED

Epidemiology of AS and the advent of transcatheter aortic valve implantation (TAVI) contribute to the extensive referral of patients. The expansion of recommendations for TAVI has occasionally led to financial reimbursement-related problems that do not exist for BAV. BAV is indicated as a bridge to valve replacement, to decision in complex cases, and to extracardiac surgery. BAV may play a role in preparing for TAVI and optimizing procedural results. The minimalist approach and reduced complication rate make it applicable in fragile patients.

EXPERT OPINION

In the near future, BAV will continue to be a useful asset in managing patients with AS given the multiple indications, broad applicability, safety profile, low cost, and repeatability. Specific studies are necessary to explore technical solutions, stronger indications, the finest technique, and to standardize the procedural result. Pending the development of potential competitive devices, the role that BAV plays will remain closely intertwined with the one played by TAVI.

Mechanical Circulatory Support in Cardiogenic Shock due to Structural Heart Disease

Despite advances in cardiovascular care, managing cardiogenic shock caused by structural heart disease is challenging. Patients with cardiogenic shock are critically ill upon presentation and require early disease recognition and rapid escalation of care. Temporary mechanical circulatory support provides a higher level of care than current medical therapies such as vasopressors and inotropes. This review article focuses on the role of hemodynamic monitoring, mechanical circulatory support, and device selection in patients who present with cardiogenic shock due to structural heart disease. Early initiation of appropriate mechanical circulatory support may reduce morbidity and mortality.

Contemporary balloon aortic valvuloplasty: Changing indications and refined technique

Even if un to improve long-term prognosis, balloon aortic valvuloplasty (BAV) may be useful in selected patients with symptomatic severe aortic stenosis either as a bridge to surgical or transcatheter valve replacement (aortic valve replacement [AVR] or transcatheter aortic valve implantation [TAVI]) or as a triage strategy for patients with uncertain indications. International guidelines recommend BAV as: a "bridge" to AVR/TAVI, a "trial" in patients with undetermined symptoms, or a "bridge-to-decision" in case of comorbidities. However, in clinical practice, BAV is also used as a palliative measure to improve hemodynamics and quality of life in many patients who are excluded from AVR/TAVI. Finally, BAV is often performed during TAVI to facilitate prosthesis delivery, optimize frame expansion, or for bioprosthetic valve fracture in selected valve-in-valve procedures. Technical innovations, which allow for a mini-invasive approach via transradial access and pacing delivered through the wire, have led to a decrease in complications over time. This review focuses on contemporary BAV with a specific emphasis on new indications, innovative techniques, and specific complex patient subgroups.

In Vitro and Ex Vivo Hemodynamic Testing of an Innovative Occluder for Paravalvular Leak After Transcather Aortic Valve Implantation

This study aims at achieving a proof-of-concept for a novel device designed to occlude the orifices that may form between transcatheter valves and host tissues after TAVI. The device effect on the performance of a SAPIEN XT with a paravalvular gap was assessed into an in vitro and ex vivo pulse duplicator. The in vitro tests were performed complying with the standard international regulations, measuring the trasvalvular pressure and regurgitant volumes with and without the paravalvular gap, and with the occluder correctly positioned into the gap. In the second series of tests, the leakage reduction due to the presence of the occluder was assessed for the same setup, into a beating swine heart. The occluder implantation decreased the regurgitant fraction of about 50% for the in vitro assessment and 75% for the ex vivo test, under rest operating conditions. These results suggest that suitably designed occluders can lead to important benefit in the PVL treatment.

In vitro assessment of pacing as therapy for aortic regurgitation

Background and objective

Clinical evaluation of pacing therapy in mitigating the aortic insufficiency after transchateter aortic valve implantation often gives contradictory outcomes. This study presents an in vitro investigation aimed at clarifying the effect of pacing on paravalvular leakage.

Methods

A series of in vitro tests reproducing the heart operating changes clinically obtained by pacing was carried out in a 26 mm Edwards Sapien XT prosthesis with mild paravalvular leakage. The effect of pacing on the regurgitant volumes per cycle and per minute was quantified, and the energy and power consumed by the left ventricle were calculated.

Results

Results indicate that though pacing results in some reduction in the total regurgitation per cycle, the volume of fluid regurgitating per minute increases substantially, causing overload of left ventricle.

Conclusions

Our tests indicate no effective haemodynamic benefit from pacing, suggesting a prudential clinical use of this therapy for the treatment of postoperative aortic regurgitation.

In vitro hemodynamic testing of Amplatzer plugs for paravalvular leak occlusion after transcatheter aortic valve implantation

OBJECTIVE

We aimed to in-vitro test Amplatzer devices (Amplatzer Vascular Plug II and Amplatzer Vascular Plug III, SJM, St. Paul, MN) in closing PVL generated by transcatheter balloon expandable aortic valve prosthesis in order to quantify the effective treatment of PVL.

BACKGROUND

Transcatheter aortic valve implantation (TAVI) procedures represent the treatment of choice for high risk patients. Despite evolving technologies paravalvular leak (PVL) is still a major unaddressed issue. This severe complication significantly impairs long-term survival. Percutaneous treatment of this complication is usually performed with the implantation of not specifically designed and not approved vascular devices.

METHODS

A 26 mm Sapien XT (Edwards Lifesciences, Irvine, CA) was implanted in a rubber aortic root and a semi-elliptical shape PVL was created. The vascular occluder devices were implanted in the PVL and hemodynamic performance was tested in a pulse duplicator according to international standard ISO 5840-3:2013. Different type of comparison tests together with high speed camera recording allowed us to define the global efficiency of the occluders and their interaction with the transcatheter prosthesis.

RESULTS

The results revealed that the use of vascular plugs was not per se sufficient to produce an effective or substantial reduction of PVL with a maximum efficiency of less than 50%. Recorded video showed clearly that the vascular plug always interfered with the leaflet of the prosthetic valve.

CONCLUSIONS

Currently used devices do not guarantee effective treatment of PVL and may otherwise compromise the structural integrity of the prosthetic valve implanted. Specifically designed devices are required.

CONDENSED ABSTRACT

Despite evolving technologies, paravalvular leak (PVL) is still a major unaddressed issue after transcatheter aortic valve implantation. Percutaneous treatment of this complication is usually performed with the implantation of Amplatzer devices not specifically designed and not approved for this specific use. We tested Amplatzer devices in a pulse duplicator to occlude PVL generated after implantation of a 26 mm SAPIENT XT prosthesis. The results revealed that the use of vascular plugs was not per se sufficient to produce an effective or substantial reduction of PVL. The video showed clearly that the vascular plug always interfered with the leaflet of the prosthetic valve.

Clinical impact of aortic regurgitation after transcatheter aortic valve replacement: insights into the degree and acuteness of presentation

OBJECTIVES

The aim of this study was to determine the impact of the degree of residual aortic regurgitation (AR) and acuteness of presentation of AR after transcatheter aortic valve replacement (TAVR) on outcomes.

BACKGROUND

The degree of residual AR after TAVR leading to excess mortality remains controversial, and little evidence exists on the impact of the acuteness of presentation of AR.

METHODS

A total of 1,735 patients undergoing TAVR with balloon-expandable or self-expanding valves were included. The presence and degree of AR were evaluated by transthoracic echocardiography; acute AR was defined as an increase in AR severity of ≥1 degree compared with pre-procedural echocardiography.

RESULTS

Residual AR was classified as mild in 761 patients (43.9%) and moderate to severe in 247 patients (14.2%). The presence of moderate to severe AR was an independent predictor of mortality at a mean follow-up of 21 ± 17 months compared with none to trace (adjusted hazard ratio [HR]: 1.81, 95% confidence interval [CI]: 1.32 to 2.48; p < 0.001) and mild AR (adjusted HR: 1.68, 95% CI: 1.27 to 2.24; p < 0.001) groups. There was no increased risk in patients with mild AR compared with those with none to trace AR (p = 0.393). In patients with moderate to severe AR, acute AR was observed in 161 patients (65%) and chronic AR in 86 patients (35%). Acute moderate to severe AR was independently associated with increased risk of mortality compared with none/trace/mild AR (adjusted HR: 2.37, 95% CI: 1.53 to 3.66; p < 0.001) and chronic moderate to severe AR (adjusted HR: 2.24, 95% CI: 1.17 to 4.30; p = 0.015) [corrected]. No differences in survival rate were observed between patients with chronic moderate to severe and none/trace/mild AR (p > 0.50).

CONCLUSIONS

AR occurred very frequently after TAVR, but an increased risk of mortality at ∼2-year follow-up was observed only in patients with acute moderate to severe AR.