 Introduction/Background Transcatheter aortic valve replacement (TAVR) has dramatically impacted the management of high-risk surgical patients [1-10], as well as medium- and low-risk patients [11], for the treatment of aortic valve disease. TAVR is a less invasive route (percutaneous endovascular) to position a prosthesis at the aortic annulus that displaces the native aortic valve leaflets toward the aortic wall. Procedure-related complications [3,5,7,8] are linked to inaccurate estimates of annular geometry; unlike surgical aortic valve replacement, the aortic annulus is not directly inspected by the proceduralist at the time of the procedure, and multiple parameters related to the annulus should be measured. Because the annulus has a complex geometry, volumetric data have emerged with standardized reformatting along patient-specific anatomic planes for annular assessment and device sizing [1,2,4,9,10,12-26]. Accurate measurements guide optimal choices for device sizing and deployment, with a secondary reduction in TAVR-related complications. The catheter-based system ranges in size between 14 and 24 Fr with transfemoral, transaxillary, and transaortic as well as direct aortic and left ventricular approaches reported; the entire aorta and branches to potential access points are evaluated for the presence, burden, and distribution of peripheral vascular atherosclerosis. This document does not elucidate the diagnosis of aortic valve disease, surgical risk stratification, [27-32] or the assessment of coronary artery disease. It is presumed that patients considered in this document are candidates for TAVR. Also, the panel did not consider planning done at the time of intervention with either catheter angiography, echocardiography, or a combination of both.
Preprocedural Planning for Transcatheter Aortic Valve Replacement.  Introduction/Background Transcatheter aortic valve replacement (TAVR) has dramatically impacted the management of high-risk surgical patients [1-10], as well as medium- and low-risk patients [11], for the treatment of aortic valve disease. TAVR is a less invasive route (percutaneous endovascular) to position a prosthesis at the aortic annulus that displaces the native aortic valve leaflets toward the aortic wall. Procedure-related complications [3,5,7,8] are linked to inaccurate estimates of annular geometry; unlike surgical aortic valve replacement, the aortic annulus is not directly inspected by the proceduralist at the time of the procedure, and multiple parameters related to the annulus should be measured. Because the annulus has a complex geometry, volumetric data have emerged with standardized reformatting along patient-specific anatomic planes for annular assessment and device sizing [1,2,4,9,10,12-26]. Accurate measurements guide optimal choices for device sizing and deployment, with a secondary reduction in TAVR-related complications. The catheter-based system ranges in size between 14 and 24 Fr with transfemoral, transaxillary, and transaortic as well as direct aortic and left ventricular approaches reported; the entire aorta and branches to potential access points are evaluated for the presence, burden, and distribution of peripheral vascular atherosclerosis. This document does not elucidate the diagnosis of aortic valve disease, surgical risk stratification, [27-32] or the assessment of coronary artery disease. It is presumed that patients considered in this document are candidates for TAVR. Also, the panel did not consider planning done at the time of intervention with either catheter angiography, echocardiography, or a combination of both.