Mehdi Eskandari

Evidence Base for Quality Control Activities in Cardiovascular Imaging

Quality control is pervasive in most modern business, but, surprisingly, is in its infancy in medicine in general-and cardiovascular imaging in particular. The increasing awareness of the cost of cardiovascular imaging, matched by a desire to show benefits from imaging to patient outcome, suggests that this deficiency should be reassessed. Demonstration of improved quality has been proposed to require a focus on several domains: laboratory organization, patient selection, image acquisition, image interpretation, and results communication. Improvement in these steps will require adoption of a variety of interventions, including laboratory accreditation, appropriate use criteria, and continuous quality control and enhancements in reporting, but the evidence base for the benefit of interventions on these steps has been sparse. The purpose of this review is to evaluate the current status and future goals of developing the evidence base for these processes in cardiovascular imaging.

Zero Contrast Transfemoral Transcatheter Aortic Valve Replacement Using Fluoroscopy-Echocardiography Fusion Imaging.

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Dynamic transcatheter mitral valve repair: a new concept to treat functional mitral regurgitation using an adjustable spacer

We report the first-in-man implantation of the Mitra-Spacer. The device was implanted transapically. FMR was reduced to moderate. At two months, while in NYHA Class II, LVEF had improved, but FMR increased and 2 mL was added, reducing FMR to mild. Despite anticoagulation, thrombi developed around the device and the valve was replaced at eight months. The Mitra-Spacer successfully bridged this patient to surgery after LVEF had recovered.

Simultaneous Transseptal Para-Ring Leak Closure and Transcatheter Mitral Valve Implantation for the Treatment of Surgical Mitral Repair Failure

Repeat cardiac surgery in patients with a previous sternotomy is associated with significant morbidity and mortality. While transcatheter aortic valve implantation in high risk surgical patients is now well established, experience with transcatheter mitral valve replacement is still at an early stage. Although many successful reports of transcatheter mitral valve replacements now exist, the predominant approach has been via a transapical approach. It is likely that, as with the evolution of favoured access routes for transcatheter aortic therapies, future directions for transcatheter mitral valves will focus on smaller delivery systems favouring the transvenous transseptal approach where possible. We present the first reported case of combined transseptal para-ring leak closure followed by transcatheter mitral valve implantation using a 12/5mm Amplatzer III vascular plug and a 29mm SAPIEN 3 valve.

Comparison of general anaesthesia and non-general anaesthesia approach in transfemoral transcatheter aortic valve implantation

Objective Performing transfemoral transcatheter aortic valve implantation (TAVI) without general anaesthesia (GA) has been increasingly adopted. We sought to study the impact of GA and non-GA approaches on procedural outcome and 30-day and 1-year mortality in transfemoral TAVI. Methods The UK TAVI registry holds information for every TAVI procedure in the UK. We analysed the data for patients implanted during 2013–2014 using either an Edwards Sapien or a Medtronic CoreValve prosthesis. Propensity score-matching analysis was performed to adjust for confounding factors. Results 2243 patients were studied (aged 81.4±7.5 years, 1195 males). 1816 (81%) underwent TAVI with GA and 427 (19%) without GA. Transoesophageal echocardiography (TOE) was used in 92.3% of GA and 12.4% of non-GA cases (p<0.001). There was no significant difference in the rate of successful valve deployment (GA 97.2% vs non-GA 95.7%, p=0.104) and in the incidence of more than mild aortic regurgitation (AR) at the end of the procedure (GA 5.6% vs non-GA 7.0%, p=0.295). However, procedure time was longer (131±60 vs 121±60mins, p=0.002) and length of stay was greater (8.0±13.5 vs 5.7±5.5 days, p<0.001) for GA cases. 30-day and 1-year mortality rates did not differ between the GA and non-GA cases. After propensity matching, these results remained unchanged. A second propensity analysis (adjusted for mode of anaesthesia) did not show an association between use of TOE and rate of successful valve deployment or frequency of significant AR. Neither was TOE associated with a longer procedural time or greater length of stay. Conclusion Procedure outcome, and 30-day and 1-year mortality are not influenced by mode of anaesthesia. However, GA is associated with longer procedure duration and greater length of stay.

Transcatheter Valve-in-Valve Therapy Using a Balloon Expanding Valve for Treatment of Aortic Paravalvular Leakage

Aortic paravalvular leakage (PVL) is a recognised complication of surgically replaced valves which is often treated using vascular plugs. Whilst transcatheter valve-in-valve therapy has been increasingly used for failed surgical bioprostheses, it is not considered as a treatment option for aortic PVL. However, the newer design of transcatheter aortic valves has a fabric skirt to create a more effective seal around the annulus. To our best knowledge, for the first time, we report successful adoption of the valve-in-valve therapy for the treatment of PVL in surgical bioprosthetic aortic valves such that the fabric skirt is placed immediately below the regurgitant orifice resulting in significant reduction in the PVL.

Use of Fluoroscopy-Echocardiography Fusion Imaging in Transcatheter Aortic Valve Replacement.

Coregistration of real time two-dimensional (2D) and three-dimensional (3D) echocardiography with fluoroscopy providing “hybrid imaging” has recently become commercially available (EchoNavigator, Philips Healthcare, Best, The Netherlands) and has been used in a range of structural heart intervention. There are a limited number of reports on how such hybrid imaging can be integrated into routine transcatheter aortic valve replacement (TAVR) procedures. The EchoNavigator system registers the transesophageal echocardiography (TEE) probe into the fluoroscopy field by a brief digital reconstruction process (Fig. 1 ). Thereafter, a specific algorithm repeatedly and rapidly repositions the reconstructed projection by tracking the TEE probe position updating the echocardiography image as the 9-ray C-arm moves. The TAVR valve requires an 9-ray angle where the aortic valve sinuses are aligned such that the virtual annulus is perpendicular to the fluoroscopy plane and hence to the TAVR valve (coplanar view). This avoids foreshortening and ensures accurate positioning of the valve prosthesis. Conventionally, aortic root angiography or prior computed tomography has been used to determine the coplanar view. However, these techniques require trials of fluoroscopic angles or previous imaging which involves more time, radiation exposure, and contrast use. Hybrid imaging can be solely used to identify the coplanar view “online” (at the time of TAVR) resulting in reduced procedural contrast volume, radiation dose, and time (Fig. 2). Not uncommonly crossing the aortic valve proves itself challenging particularly with bicuspid native valves or stenosed bioprostheses. The stenotic aortic valve orifice can be marked by EchoNavigator on the fluoroscopy image to guide the interventionist in crossing the valve (Fig. 3). Finally, the fused 3D echo image on the fluoroscopy screen can improve precision in valve positioning and deployment (Fig. 4, movie clip S1), especially where the valve is not very calcified or the distribution of calcification can be misleading. Improvement in 3D echo device visualization may allow for device deployment without the use of contrast at all, with a consequent reduction in radiation and more precise device positioning.

The old and the new: the pivotal role of TTE in TAVI

Transcatheter aortic valve implantation (TAVI) has undeniably revolutionised the field of interventional cardiology regarding the treatment of aortic stenosis (AS). With promising outcomes from the recently published PARTNER 2 trial (1), involving patients at intermediate risk for surgical treatment, further growth of an already rapidly expanding field is expected. Echocardiography has a pivotal role in transcatheter therapies from the early steps when the clinical diagnosis of a valvular disease is made to the postprocedural long-term follow-up. Although the role of transoesophageal echocardiography (TOE) for either pre-procedural planning or intraoperative guidance in TAVI has been the subject of several reviews and debates, the role of the older member of the family, transthoracic echocardiography (TTE), has not been given the attention it deserves. In this issue of Echo Research and Practice, Fryearson and coworkers review the role of TTE before and following TAVI and discuss as how it helps inform clinical decision-making in TAVI (2).