|3-Class Grading Scheme||Trace||Mild||Mild||Moderate||Moderate||Severe|
|4-Class Grading Scheme||1||1||2||2||3||4|
|Unifying 5-Class Grading Scheme||Trace||Mild||Mild-to-Moderate||Moderate||Moderate-to-Severe||Severe|
|Cineangiography||Grade 1||Grade 1||Grade 1||Grade 2||Grade 3||Grade 4|
|Aortic regurgitation index∗||>25||>25||>25||10–25||10–25||<10|
|● Valve stent||Usually normal||Usually normal||Normal/abnormal†||Normal/abnormal†||Usually abnormal†||Usually abnormal†|
|○ LV size‡||Normal||Normal||Normal||Normal/mildly dilated||Mildly/moderately dilated||Moderately/severely dilated|
|Doppler parameters (qualitative or semiquantitative)|
|● Jet features§|
|Extensive/wide jet origin||Absent||Absent||Absent||Present||Present||Present|
|Multiple jets||Possible||Possible||Often present||Often present||Usually present||Usually present|
|Jet path visible along the stent||Absent||Absent||Possible||Often present||Usually present||Present|
|Proximal flow convergence visible||Absent||Absent||Absent||Possible||Often present||Often present|
|○ Vena contracta width (mm): color Doppler‖||<2||<2||2–4||4–5||5–6||>6|
|○ Vena contracta area (mm2): 2D/3D color Doppler¶||<5||5–10||10–20||20–30||30–40||>40|
|● Jet width at its origin (%LVOT diameter): color Doppler‖||Narrow (<5)||Narrow (5–15)||Intermediate (15–30)||Intermediate (30–45)||Large (45–60)||Large (>60)|
|○ Jet density: CW Doppler||Incomplete or faint||Incomplete or faint||Variable||Dense||Dense||Dense|
|○ Jet deceleration rate (PHT, ms): CW Doppler∗‡||Slow (>500)||Slow (>500)||Slow (>500)||Variable (200–500)||Variable (200–500)||Steep (<200)|
|○ Diastolic flow reversal in the descending aorta: PW Doppler∗‡||Absent||Absent or brief early diastolic||Intermediate||Intermediate||Holodiastolic (end-diast. vel. >20 cm/s)||Holodiastolic (end-diast. vel. >25 cm/s)|
|● Circumferential extent of PVR (%): color Doppler‖||<10||<10||10–20||20–30||>30||>30|
|Doppler parameters (quantitative)|
|○ Regurgitant volume (ml/beat)#||<15||<15||15–30||30–45||45–60||>60|
|○ Regurgitant fraction (%)||<15||<15||15–30||30–40||40–50||>50|
|○ Effective regurgitant orifice area (mm2)∗∗||<5||<5||5–10||10–20||20–30||>30|
|Cardiac magnetic resonance imaging|
|Regurgitant fraction (%)††||<10|
● Parameters that are most frequently applicable and used to grade PVR severity by echocardiography. ○ Parameters that are less often applicable due to pitfalls in the feasibility/accuracy of the measurements and/or to the interaction with other factors. Online Videos 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, and 36 provide Doppler color images (parasternal short- and long-axis, apical 5- and 3-chamber views) of representative cases for each class (except none and severe PVR) of the unifying 5-class grading scheme proposed in this table.
2D = 2-dimensional; 3D = 3-dimensional; AR = aortic regurgitation; CW = continuous wave; end diast. vel. = end-diastolic velocity; LV = left ventricular; LVOT = left ventricular outflow tract; PHT = pressure half-time; PVR = paravalvular regurgitation; PW = pulsed wave; RV = right ventricular; TAVR = transcatheter aortic valve replacement.
↵∗ These parameters are influenced by LV and aortic compliance. In particular, low transvalvular end-diastolic aorta to LV pressure gradient that is due to concomitant moderate/severe LV diastolic dysfunction may lead to false-positive results. The high dependency of aortic flow reversal on aortic compliance considerably limits the utility of this parameter in the elderly population undergoing TAVR. These parameters are also influenced by chronotropy.
↵† Abnormalities of stent position (too low or too high), deployment, and/or circularity.
↵‡ Applies to chronic PVR but is less reliable for periprocedural or early post-procedural assessment.
↵§ See Figure 9 for illustrative images.
↵‖ These parameters are generally assessed visually.
↵¶ The vena contracta area is measured by planimetry of the vena contracta of the jet(s) on 2D or 3D color Doppler images in the short-axis view (Figure 8).
↵# Regurgitant volume is calculated as the difference of stroke volume measured in the LV outflow tract minus the stroke volume measured in the right ventricular outflow tract (see Figure 10).
↵∗∗ The effective regurgitant orifice area is calculated by dividing the regurgitant volume by the time-velocity integral of the AR flow by CW Doppler.
↵†† There are important variability in the cutpoint values of regurgitant fraction and volume reported in the published studies to grade AR by cardiac magnetic resonance imaging.