The role of magnetic resonance imaging in the development of novel transcatheter cardiovascular interventions

Abstract

Transcatheter cardiovascular interventions are an increasingly attractive alternative to open-­‐ chest surgery. Fluoroscopy, historically the cornerstone of imaging guidance for transcatheter procedures, has fundamental limitations when operating in three-­‐dimensions and cannot visualise soft tissue. Structural heart and electrophysiology interventions require precise device localisation in space and direct visualization of anatomic structures. Cardiovascular magnetic resonance imaging (CMR) offers a number of tools that may be ideally suited to these advanced applications: excellent soft tissue visualization in unlimited imaging planes, real-­‐time procedural guidance, three-­‐dimensional imaging, quantification of blood flow and tissue characterization techniques.

In this thesis we describe four original interventions and explore the role of CMR at each stage of the development process: defining the clinical problem, designing potential solutions, building and testing prototypes, and evaluating device performance in pre-­clinical experiments. The first structural heart intervention, transatrial intrapericardial tricuspid annuloplasty, is a percutaneous therapy for functional tricuspid regurgitation. CMR was used to determine device configuration and evaluate device-­‐imparted geometric change to the heart. The second structural heart intervention, intentional right atrial exit and pericardial CO2 insufflation, facilitates easy and safe subxiphoid access to the naïve pericardial space. CMR was used to quantify pericardial effusion volume over time, a key parameter that is impossible to measure with fluoroscopy or echocardiography. The third structural heart intervention, fully percutaneous transthoracic left atrial entry and closure, is a potential access route to deliver large transcatheter prostheses to the mitral valve. Transthoracic trajectories to the left atrium were planned and the procedure was performed using real time CMR guidance and active visualization devices. The fourth electrophysiology intervention, transcatheter myocardial needle chemoablation was also performed under CMR guidance, enabling arrhythmic substrate and ablation lesion visualization in real time. The purpose of this thesis is to explore the role of CMR in the development of each of these novel transcatheter interventions.

Date of Award	2017
Original language	English
Awarding Institution	King's College London
Supervisor	Valentina Puntmann (Supervisor)