CT-Based Factors for TAVI Valve Selection

Core Anatomical Measurements for Valve Selection

The American College of Cardiology recommends that annular area (mm²) is the most critical measurement for prosthesis sizing and should be measured at the annular plane defined by the lowest insertion points of the aortic valve cusps 1
Annular perimeter (mm) and minimum/maximum diameters provide additional sizing information, according to the American Heart Association 1
Left main coronary artery height (mm) and right coronary artery height (mm) must be measured to assess risk of coronary obstruction, as stated by the European Society of Cardiology 1
Low coronary heights (<10-12 mm) represent adverse root features that may influence valve type selection, according to the American College of Cardiology 1

The European Society of Cardiology recommends that sinus of Valsalva (SoV) averaged diameter (mm) should be measured across all three sinuses; for symmetric anatomies, the three values can be averaged 2
Sinotubular junction (STJ) diameter and height must be assessed, particularly when using balloon-expandable devices, as stated by the American Heart Association 2
When STJ diameter is smaller than anticipated transcatheter heart valve (THV) diameter, there is increased risk for STJ injury, which may favor self-expanding valve selection, according to the European Society of Cardiology 2

Valve morphology must be categorized: tricuspid, congenital bicuspid (using Sievers classification), or functional/acquired bicuspid, as recommended by the American College of Cardiology 1
Bicuspid valve anatomy requires modified measurement techniques, identifying the annular plane using the two most basal cusp insertion points, according to the European Society of Cardiology 2
Calcium distribution should be characterized as symmetric versus asymmetric, and crescent non-protruding versus bulky protruding, as stated by the American Heart Association 1
Bulky calcification at the free edge or intramural calcification patterns influence valve type selection, according to the American College of Cardiology 1

Minimal vessel diameters with location, extent of calcification (mild/moderate/severe), and tortuosity determine feasibility of transfemoral approach and may influence valve delivery system selection, as recommended by the European Society of Cardiology 1
Horseshoe or circumferential calcium patterns at the common femoral artery access site are adverse features, according to the American Heart Association 1

For balloon-expandable valves, precise annular measurements with particular attention to STJ dimensions are required, as stated by the American College of Cardiology 2
Self-expanding valves are more accommodating for anatomies with STJ constraints, according to the European Society of Cardiology 2

Determine if surgical valve is stented versus stentless, as this fundamentally changes the assessment approach, as recommended by the American Heart Association 3, 4
Virtual THV to coronary (VTC) distance must be measured if stent posts extend to or above coronary ostia level, according to the European Society of Cardiology 3, 5
VTC <4 mm indicates increased risk of coronary obstruction and may contraindicate certain valve choices, as stated by the American College of Cardiology 3, 5

In bicuspid valves, failure to properly identify the annular plane using the two most basal insertion points leads to inaccurate sizing, according to the European Society of Cardiology 2
Overlooking bulky calcification patterns may result in paravalvular leak or deployment complications, as stated by the American College of Cardiology 1
Inadequate assessment of coronary heights, particularly in valve-in-valve cases, risks catastrophic coronary obstruction, according to the American Heart Association 3, 5