Background
Methods
Patient population
Transthoracic echocardiography (TTE)
Cardiac magnetic resonance (CMR)
Fusion of Doppler with CMR data
Statistical analysis
Results
Baseline clinical, hemodynamic and echocardiographic characteristics
Severe HG-SAS (n = 120) | Severe Paradoxical NF-LG-AS (n = 45) | Severe Paradoxical LF-LG-AS (n = 25) |
p-value | |
---|---|---|---|---|
Age, yrs | 73 ± 12 | 74 ± 14 | 74 ± 14 | 0.44 |
Male gender, n (%) | 77 (64%) | 21 (47%)*
| 10 (40%)*
| 0.02 |
Body surface area, kg/m2
| 1.86 ± 0,19 | 1.81 ± 0,21 | 1.83 ± 0,20 | 0.83 |
Arterial hypertension, n (%) | 84 (70%) | 38 (84%)*
| 21 (88%)*
| 0.046 |
Diabetes, n (%) | 20 (17%) | 12 (27%) | 6 (24%) | 0.29 |
Hyperlipidemia, n (%) | 86 (72%) | 27 (60%) | 24 (96%)*,†
| 0.01 |
Prior myocardial infarction, n (%) | 5 (4%) | 7 (16%)*
| 3 (13%) | 0.04 |
Prior coronary revascularization, n (%) | 15 (13%) | 5 (11%) | 5 (20%) | 0.49 |
Atrial fibrillation, n (%) | 2 (2%) | 1 (2%) | 5 (20%)*,†
| <0.01 |
Severe HG-SAS (n = 120) | Severe Paradoxical NF-LG-AS (n = 45) | Severe Paradoxical LF-LG-AS (n = 25) |
p-value | |
---|---|---|---|---|
Hemodynamic data
| ||||
Heart rate, bpm | 68 ± 10 | 69 ± 14 | 76 ± 16 | 0.17 |
Systolic blood pressure, mmHg | 133 ± 17 | 141 ± 22*
| 139 ± 21 | 0.70 |
Diastolic blood pressure, mmHg | 74 ± 11 | 76 ± 11 | 75 ± 12 | 0.88 |
CMR findings
| ||||
Indexed LV EDV, mL/m2
| 81 ± 18 | 73 ± 18*
| 67 ± 14*,†
| <0.01 |
Indexed LV ESV, mL/m2
| 28 ± 10 | 26 ± 12 | 25 ± 8 | 0.14 |
Indexed SV, mL/m2
| 54 ± 10 | 49 ± 9 | 43 ± 10 | <0.01 |
LV ejection fraction, % | 59 ± 5 | 60 ± 6 | 57 ± 5 | 0.74 |
CMR LVOT diameter, mm | 22 ± 2 | 21 ± 2 | 21 ± 2*
| 0.20 |
CMR LVOT area, cm2
| 5.0 ± 1.0 | 4.6 ± 0.9*
| 4.6 ± 0.7 | 0.04 |
CMR LVOT ellipticity index | 1.28 ± 0.08 | 1.28 ± 0.07 | 1.30 ± 0.10 | 0.64 |
2D-Doppler and Doppler findings
| ||||
2D-LVOT diameter, mm | 22 ± 2 | 22 ± 2 | 20 ± 1*,†
| 0.02 |
2D-echo LVOT area, cm2
| 3.8 ± 0.8 | 3.7 ± 0.6 | 3.3 ± 0.5*
| 0.02 |
3D-echo LVOT area, cm2
| 5.3 ± 1.0 | 4.9 ± 0.9 | 4.6 ± 0.9 | 0.36 |
LVOT VTI, cm/s | 22 ± 4 | 22 ± 3 | 16 ± 3*,†
| <0.01 |
2D-indexed SV, mL/m2
| 44 ± 9 | 42 ± 5 | 29 ± 4*,†
| <0.01 |
Peak transaortic flow velocity, cm/s | 472 ± 49 | 366 ± 36*
| 344 ± 42*,†
| <0.01 |
Mean pressure gradient, mm Hg | 56 ± 12 | 32 ± 6*
| 29 ± 7*,†
| <0.01 |
2D-indexed AVA, cm2/m2
| 0.38 ± 0.08 | 0.49 ± 0.06*
| 0.39 ± 0.08†
| <0.01 |
Fused data
| ||||
Fused indexed SV, mL/m2
| 57 ± 10 | 54 ± 8*
| 41 ± 5*,†
| <0.01 |
Fused indexed AVA, cm2/m2
| 0.49 ± 0.09 | 0.62 ± 0.10*
| 0.54 ± 0.11*,†
| <0.01 |
LVOT dimensions by 2D-echocardiography and CMR
Stroke volume and continuity equation-derived AVA using 2D-echocardiography and CMR LVOT areas
Impact of LVOT eccentricity on AS classification
3D-echo vs CMR LVOT areas
Variability of measurements
Discussion
-
In almost every patient, the LVOT exhibits an elliptical shape, with a larger transverse than anterior-posterior diameter;
-
Inputting the CMR planimetered LVOT area into the continuity equation increased the indexed stroke volume and the indexed AVA by 29% and significantly reduced the bias between echocardiographic and CMR data;
-
Based on the fused indexed AVAs, 55% of patients with severe paradoxical NF-LG-AS, 20% of patients with severe paradoxical LF-LG-AS and 16% of patients with severe HG-AS were reclassified as having only moderate AS. Use of the fused indexed AVA improved the concordance between Doppler-echocardiography and CMR by an average of 10%.