By Vinayak Bapat
Vinayak Bapat won the 2013 Techno College Innovation award at the recent European Association for Cardio-Thoracic Surgery meeting (EACTS; 5–9 October, Vienna, Austria) for developing a smartphone app that provides advice on performing valve-in-valve procedures. He writes about the key features of the app and explains why he feels such an app is necessary
Rapid growth and confidence in transcatheter aortic valve implantation (TAVI) technology has led to TAVI devices being used in novel indications, such as the treatment of a degenerated bioprosthetic surgical heart valve. Therefore, multiple reports of valve-in-valve procedures have appeared in the literature during the last three years, and substantial experience has now been acquired in treating degenerated surgical heart valves in the aortic position. There is also increasing experience of valve-in-valve procedures in the mitral, tricuspid and pulmonary positions. At the moment, the Edwards’ Sapien/Sapien XT and Medtronic’s CoreValve/Evolute devices have been predominantly been used in these procedures. However, the ever-growing list of newer TAVI devices will also probably be used for valve-in-valve procedures—for example, the latest valves to be used for this indication are St Jude Medical’s Portico, Medtronic’s Melody (for the pulmonary valve), and Jenavalve Technology’s Jenavalve.
The success of a valve-in-valve procedure is based on the correct identification of the surgical valve, choosing the correct size of the TAVI valve and its subsequent accurate placement. Incorrect size and placement will result in a suboptimal result and will reflect in short term and long-term outcomes.
However, as with all new technologies, evidence for their use is limited when used in novel indications; therefore, there is a need to provide TAVI users with robust information to achieve higher success rate and avoid problems. We wrote a report (published in Catheterization and Cardiovascular Interventions) that described fluoroscopic appearances of all stented surgical heart valves with a complete table of important dimensions. Subsequent publications have provided information for “ideal implant position” and “true internal diameter”, which dictates the best match for a given surgical heart valve. However, publications take a long time to reach the users and, hence, we felt that we should design a smartphone/tablet app to make information on valve-in-valve procedures available to interventional cardiologists anywhere in the world.
The first App in the series was the valve-in-valve aortic app, which provides users with information about various stented and TAVI valves. We subsequently added information on stentless valves—users of the app can now familiarise themselves with important design information about a specific valve. They can then choose a labelled size and find out which size of TAVI valve could be used and how it is best placed during a valve-in-valve procedure using various devices. A short film clip of an actual case can also be accessed. If the valve type is unknown, the app also guides the user through a series of steps where they can identify the surgical valve type and then use the information available for it.
There are additional sections such as similar looking valves and True ID [the effective internal diameter of a valve once the leaflet tissue is mounted on the frame], which give users additional information about the therapy area.
We later released a second app in the series—valve-in-valve mitral, which specific to the valves and rings used in the mitral position. In addition to the information about mitral valves and rings, the app reviews differences between an aortic valve-in-valve and a mitral valve-in-valve procedure.
The idea of the apps is to provide information specific for a clinical scenario, quickly and simply, and help reduce the need to trawl through vast amounts of literature to find information for planning and performing a valve-in-valve or valve-in-ring case. Our goal is to have education that is free, easy to use and is at doctors’ fingertips. The information is also available without the need for an internet connection as the data including movie clips are downloaded on the smartphone and will enhance the users understanding of various aspects of this procedure. We hope this will result in improved results and better outcomes for patients. This is a rapidly developing field and as more transcatheter heart valves are used the information will be updated and new apps added to this series to keep pace with newer developments.
Both the aortic and mitral apps are available from the Apple store and will be released on Google Apps market place for android users. A third app in the series will be released with data and information on newer transcatheter heart valve devices as they become available for valve-in-valve use.
Vinayak Bapat, consultant cardiothoracic surgeon, Guys and St. Thomas’ Hospital, London, UK