Page 13 - Journal of Structural Heart Disease Volume 5, Issue 2

Original Scientific Article
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with severe symptomatic AS who are at intermediate surgical risk [14].
Traditionally, TAVR procedure has been performed using a high resolution, multifunction, mounted an- giography system (MAS), often utilizing computed to- mography (CT) overlay technology to optimize valve positioning. A portable angiography system (PAS)— defined as a mobile C-arm fluoroscopic system capa- ble of obtaining high quality angiographic images with cineography, digital subtraction, and archiving abilities [15-17]—is an alternative imaging modality that has been less commonly used in structural heart interventions. Instead, PAS has more frequently been utilized in endovascular, urologic, orthopedic and gastroenterology procedures [15, 18]. In the past, PAS has been limited by poor image resolution, small field of view, longer procedure times with frequent system overheating, and potential breach of sterili- ty from C-arm rotation [19-22]. As a result, it has not been seen as a feasible alternative to current mount- ed camera use during TAVR [20]. However, with the recent production of digital, high-resolution, liquid cooled PAS, the new generation of portable imaging addresses many of these perceived limitations.
While PAS has been used during TAVR in select institutions outside the United States [23], to our knowledge, the role and safety of PAS have not been systematically studied in TAVR. Herein, we propose that the new generation of high-powered, high-reso- lution PAS may be implemented as a safe and feasible alternative to MAS. In this study, we compare clinical and procedural outcomes of high-risk patients with severe symptomatic AS undergoing TAVR using a tra- ditional MAS versus a new generation PAS.
Methods
Study design
A retrospective study was conducted on 101 con- secutive TAVR cases performed at our center from December 09, 2014 to November 15, 2016. The study was approved and performed in accordance with the hospital institutional review board at United Health Services Hospitals (UHSH) Wilson Medical Center, Johnson City, NY. Patients underwent transcatheter valve replacement for the treatment of severe symp- tomatic AS. All candidates received standard preoper-
ative evaluation by the institution’s heart valve team, which consisted of cardiologists (valve specialists, imaging specialists, and interventionalists) and car- diothoracic surgeons. Operative risk was measured by the Society of Thoracic Surgeons (STS) predicted risk of mortality score, which was calculated using the online STS Adult Cardiac Surgery Risk Calculator [24]. Patients with a STS risk score of 3% or greater, or oth- erwise deemed at prohibitive risk for open surgical repair, were candidates for TAVR. The default vascular access route for transcatheter intervention was trans- femoral. However, when the ileofemoral approach was unfeasible, an ideal alternative access (transaor- tic, transapical, or transsubclavian) was chosen based on individual patient anatomy.
TAVR procedures were performed using either a new generation PAS or a traditional MAS fluoroscopic camera, which were allocated in a randomized fash- ion based on hybrid operating room (OR) and cam- era availability. Pulsed fluoroscopy and cineography imaging modes were used in all cameras. Three cam- eras were used in the PAS group: Siemens Cios Al- pha, Ziehm Vision RFD (RFD), and GE OEC 9900 Elite (GE9900). Three cameras were used in the MAS group: GE Advantx DLX, Philips Allura Xper FD20 (FD20), and Siemens Artis zee biplane. None of the systems were equipped with CT overlay functionality. Intraopera- tively, transesophageal or transthoracic echocardi- ography (TTE) was performed adjunctively to guide fluoroscopic assessment of prosthesis implantation.
All patients received either a balloon-expandable (Edwards SAPIEN XT or SAPIEN 3, Edwards Lifescienc- es, Irvine, CA, USA) or self-expandable (Medtronic CoreValve Evolut, Medtronic, Minneapolis, MN, USA) prosthetic aortic valve, with a diameter of 23, 26, or 29 mm. The optimal valve type and size were select- ed based on patient specific anatomical and clinical factors.
Data collection and definitions
Baseline demographic and procedural character- istics were collected from the UHSH computerized health record. The STS risk score served as a proxy for coexisting medical conditions. Body mass index (BMI) was calculated using recorded height and weight. Baseline New York Heart Association (NYHA) heart fail- ure class and left ventricular ejection fraction (LVEF)
Journal of Structural Heart Disease, April 2019
Volume 5, Issue 2:25-37