Transcatheter aortic valve implantation with the self-expandable CoreValve (CV) and the balloon-expandable Edwards SAPIEN (ES) bioprostheses has been widely used for the treatment of severe aortic stenosis. However, a direct comparison of the hemodynamic results associated with these 2 prostheses is lacking. The aim of the present study was to compare the hemodynamic performance of both bioprostheses. A total of 41 patients who underwent transcatheter aortic valve implantation with the CV prosthesis were matched 1:1 for prosthesis size (26 mm), aortic annulus size, left ventricular ejection fraction, body surface area, and body mass index with patients who underwent transcatheter aortic valve implantation with the ES prosthesis. Doppler-echocardiographic data were prospectively collected before the intervention and at hospital discharge, and all examinations were sent to, and analyzed in, a central echocardiography core laboratory. The mean transprosthetic residual gradient was lower (p = 0.024) in the CV group (7.9 ± 3.1 mm Hg) than in the ES group (9.7 ± 3.8 mm Hg). The effective orifice area tended to be greater in the CV group (1.58 ± 0.31 cm 2 vs 1.49 ± 0.24 cm 2 , p = 0.10). The incidence of severe prosthesis–patient mismatch was, however, similar between the 2 groups (effective orifice area indexed to the body surface area ≤0.65 cm 2 /m 2 ; CV 9.8%, ES 9.8%, p = 1.0). The incidence of paravalvular aortic regurgitation was greater with the CV (grade 1 or more in 85.4%, grade 2 or more in 39%) than with the ES (grade 1 or more in 58.5%, grade 2 or more in 22%; p = 0.001). The number and extent of paravalvular leaks were greater in the CV group (p <0.01 for both comparisons). In conclusion, transcatheter aortic valve implantation with the CV prosthesis was associated with a lower residual gradient but a greater rate of paravalvular aortic regurgitation compared to the ES prosthesis. The potential clinical consequences of the differences in hemodynamic performance between these transcatheter heart valves needs to be addressed in future studies.
Currently, 2 different transcatheter aortic valves are widely used, with extensive data on their feasibility, safety, and clinical outcomes: the self-expandable CoreValve (CV) prosthesis (Medtronic, Minneapolis, Minnesota) and the balloon-expandable Edwards SAPIEN (ES) prosthesis (Edwards Lifesciences, Irvine, California). Although both CV and ES prostheses have been shown to be associated with excellent hemodynamic results, recent studies have suggested some differences in the hemodynamic performance of these 2 valves, with the CV prosthesis associated with a lower residual gradient and greater valve area, especially for the treatment of surgical prosthesis dysfunction. Also, the United Kingdom Transcatheter Aortic Valve Implantation Registry (UK registry) and FRench Aortic National Corevalve and Edwards (FRANCE 2) registry, which included a large number of patients treated with the CV and ES devices showed significant differences in the presence and degree of aortic regurgitation (AR), with the CV associated with a greater rate of residual AR. However, all these studies included patients with different aortic annulus and valve sizes, and, more importantly, the data were not analyzed at a central independent echocardiographic core laboratory. This might have precluded drawing definite conclusions regarding the potential differences in valve performance between the 2 transcatheter valve devices. The objective of the present study was therefore to compare the hemodynamic performance and the presence and severity of residual AR after transcatheter aortic valve implantation of the 26-mm CV and ES bioprostheses, as evaluated in a case-matched population by an independent central echocardiographic core laboratory.
Methods
A total of 107 consecutive patients with severe symptomatic aortic stenosis underwent transcatheter aortic valve implantation with the third-generation CV device at 2 centers. Of these, 58 patients were excluded because of implantation of a 29-mm valve in 41 patients, an unsuccessful procedure in 11 patients, and in-hospital death precluding transthoracic echocardiography at hospital discharge in 6 patients. Therefore, 49 patients had successful implantation of a 26-mm CV device. These patients were matched 1:1 with patients who had undergone transcatheter aortic valve implantation with the 26-mm ES valve. These patients were drawn from a prospective database of 126 consecutive patients who had received the 26-mm ES valve and survived the periprocedural period at 2 centers. The matching criteria (all pre-transcatheter aortic valve implantation) were (1) prosthesis size (26-mm, exact match), (2) aortic annulus diameter (within 0.5 mm) measured using transthoracic echocardiography, (3) left ventricular ejection fraction (within 10%) measured using transthoracic echocardiography, and (4) body surface area (within 0.4 m 2 ), and body mass index (within 5 kg/m²). The matching was not possible in 8 patients, leading to a final study population of 41 patients per group. If >1 patient who had received an ES valve could be matched with a CV patient, the final matching was performed by random sampling without replacement using the bootstrap method. The values of the matched variables, according to valve type, are listed in Table 1 . All patients provided written informed consent for the procedures. The transcatheter aortic valve implantation procedure has been explained in detail in previous publications. All CV procedures were performed using the transfemoral approach. The ES procedures were performed using the transfemoral approach in 12 patients and the transapical approach in 29 patients. The procedures were guided by fluoroscopy or angiography and transesophageal echocardiography. The final selection of prosthesis size was determined by procedural transesophageal echocardiographic assessment of the aortic annulus. The mean aortic annulus measurement as determined by transesophageal echocardiography of the CV and ES groups was 22.0 ± 1.0 mm and 22.3 ± 1.0 mm, respectively (p = 0.20). The patients were followed up by clinical visits and/or through telephone interviews at 1, 6, and 12 months and yearly thereafter in all participating centers. No patient was lost to follow-up, and the occurrence of mortality at any point during the follow-up period was prospectively recorded by each participating center.
| Variable | All (n = 82) | CV (n = 41) | ES (n = 41) | p Value |
|---|---|---|---|---|
| Aortic annulus diameter (mm) | 20.5 ± 1.1 | 20.4 ± 1.2 | 20.6 ± 1.1 | 0.405 |
| Indexed aortic annulus diameter (mm/m 2 ) | 11.8 ± 1.3 | 11.8 ± 1.2 | 11.8 ± 1.4 | 0.979 |
| Left ventricular ejection fraction (%) | 59.0 ± 11.6 | 59.7 ± 11.8 | 58.2 ± 11.5 | 0.558 |
| Body surface area | 1.75 ± 0.18 | 1.74 ± 0.16 | 1.76 ± 0.21 | 0.533 |
| Body mass index (kg/m 2 ) | 25.4 ± 4.5 | 25.4 ± 4.9 | 25.4 ± 4.2 | 0.976 |
The patients underwent a complete transthoracic echocardiographic examination, according to the guidelines of the American Society of Echocardiography, before the procedure and at hospital discharge (available for all patients) and at 6 to 12 months after the procedure (available for 24 matched patients). All echocardiographic examinations were sent to the echocardiography core laboratory of the Quebec Heart and Lung Institute (directed by P.P. and J.G.D.) for analysis. All images were stored in digital format, and the analyses were performed offline by experienced technicians who were unaware of the clinical data and supervised by a cardiologist (J.G.D.) using an Image Arena Platform (TomTec Imaging Systems, Unterschleissheim, Germany). The following measurements were obtained for all patients: aortic annulus diameter, left ventricular outflow tract diameter, stroke volume, left ventricular ejection fraction evaluated using the biplane Simpson method, the mean and maximum transvalvular gradient estimated with the modified Bernoulli formula, and valve effective orifice area (EOA) calculated using the continuity equation. The aortic annulus was measured in a zoomed parasternal long-axis view from the hinge point of the anterior aortic cusp and the ventricular septum to the junction of the posterior aortic cusp and the anterior mitral leaflet. The left ventricular outflow tract diameter was measured just underneath the apical margin of the prosthesis stent. The left ventricular outflow tract Doppler recordings were also obtained just below the stent margin to ensure that the flow velocities were recorded at the same location as the left ventricular outflow tract diameter. If the transcatheter valve was positioned low in the left ventricular outflow tract with the stent margin close to the apical end of the left ventricular outflow tract, the measures of the left ventricular outflow tract diameter and velocity were obtained within the stent just below the transcatheter valve leaflets. The Doppler velocity index was calculated as the left ventricular outflow tract velocity/transvalvular velocity ratio.
The EOA was indexed to the body surface area, and the presence of prosthesis–patient mismatch (PPM) was defined as an indexed EOA ≤0.85 cm 2 /m 2 . A PPM was considered to be moderate if the indexed EOA was 0.65 to 0.85 cm 2 /m 2 , and severe if the indexed EOA was ≤0.65 cm 2 /m 2 . The presence, degree, and type (paravalvular vs transvalvular) of AR was recorded for all patients. The AR severity was evaluated using a multiparametric approach as recommended by the American Society of Echocardiography and European Association of Echocardiography guidelines and classified as follows: grade 0, absent-trace; grade 1, mild; grade 2, mild-to-moderate; grade 3, moderate-to-severe; and grade 4, severe. In the presence of paravalvular AR, the number of jets, localization, and the circumferential extent were also assessed. The circumferential extent of the paravalvular jets was measured in the parasternal short-axis views with color Doppler. When both valvular and paravalvular AR were present, AR was expressed as an overall grade, unless mentioned. All statistical analyses were performed using the SPSS software, version 18 (SPSS, Chicago, Illinois). Categorical variables are expressed as frequencies and comparisons between groups were performed using the chi-square test. Continuous variables are expressed as the mean ± SD or median and 25th to 75th interquartile range and analyzed for normal distribution using the Shapiro-Wilk test. Comparisons were done using the t test or the Mann-Whitney U test, depending on the variable distribution. Analysis of variance for repeated measures was performed to test for equal means at different times (baseline; discharge; and 6 to 12 months) for the mean gradient and valve area values, and 2-way analysis of variance for repeated measures with interaction was used to compare the changes at different points between the groups (CV vs ES). Differences were considered statistically significant at p <0.05.
Results
The baseline clinical and echocardiographic data are listed in Tables 2 and 3 , respectively. The echocardiographic data after transcatheter aortic valve implantation with the CV and ES prostheses are listed in Table 4 . The overall mean transprosthetic gradient decreased from 46.0 ± 16.3 mm Hg to 8.8 ± 3.6 mm Hg (p <0.001), and the mean EOA increased from 0.61 ± 0.14 cm 2 to 1.55 ± 0.28 cm 2 (p <0.001) after transcatheter aortic valve implantation. The patients in the CV group exhibited a lower peak and mean residual transprosthetic gradient compared to the ES group (p = 0.019 for peak gradient; p = 0.024 for mean gradient; Table 4 and Figure 1 ). A tendency (p = 0.08) was seen toward a greater indexed EOA in the CV group than in the ES group ( Table 4 and Figure 1 ). The incidence of PPM also tended to be lower (p = 0.10) in CV group (34.1%) than in the ES group (56.1%), but no difference (p = 1.0) was observed in the incidence of severe PPM (9.8% for CV and ES groups). In the ES group, no differences was seen between the transfemoral and transapical approaches (p >0.20 for mean gradient and valve area; p = 0.54 for AR).
| Variable | All (n = 82) | CV (n = 41) | ES (n = 41) | p Value |
|---|---|---|---|---|
| Age (yrs) | 83 ± 6 | 84 ± 5 | 82 ± 7 | 0.166 |
| Men | 50 (61%) | 24 (59%) | 26 (63%) | 0.651 |
| Body surface area (m 2 ) ∗ | 1.75 ± 0.18 | 1.74 ± 0.16 | 1.76 ± 0.21 | 0.533 |
| Body mass index (kg/m 2 ) ∗ | 25.4 ± 4.5 | 25.4 ± 4.9 | 25.4 ± 4.2 | 0.976 |
| Hypertension † | 71 (87%) | 36 (88%) | 35 (85%) | 0.746 |
| Dyslipidemia ‡ | 61 (75%) | 31 (76%) | 30 (75%) | 0.949 |
| Diabetes mellitus | 23 (28%) | 12 (29%) | 11 (27%) | 0.806 |
| Chronic atrial fibrillation | 31 (38%) | 14 (34%) | 17 (42%) | 0.494 |
| Coronary artery disease § | 61 (74%) | 31 (76%) | 30 (73%) | 0.800 |
| Cerebrovascular disease | 17 (21%) | 8 (20%) | 9 (22%) | 0.785 |
| Chronic obstructive pulmonary disease | 17 (21%) | 10 (24%) | 7 (17%) | 0.414 |
| Estimated glomerular filtration rate (ml/min) | 63.1 ± 26.7 | 65.7 ± 27.8 | 60.5 ± 25.6 | 0.376 |
| Society of Thoracic Surgeons predicted risk of mortality (%) | 8.3 ± 5.8 | 8.4 ± 6.5 | 8.2 ± 5.0 | 0.844 |
| Frailty | 15 (18%) | 8 (20%) | 7 (17%) | 0.775 |
† Blood pressure >140/90 mm Hg for patients without diabetes or chronic kidney disease; blood pressure >130/80 mm Hg for patients with diabetes or chronic kidney disease; or documented history of hypertension diagnosed and treated.
‡ Total cholesterol >200 mg/dl, low-density lipoprotein ≥130 mg/dl, or high-density lipoprotein <40 mg/dl in men and <50 mg/dl in women.
§ Presence of coronary lesions with diameter stenosis ≥50% in vessels ≥2.0 mm or previous coronary revascularization, irrespective of the presence of coronary lesions ≥50%.
| Variable | All (n = 82) | CV (n = 41) | ES (n = 41) | p Value |
|---|---|---|---|---|
| Aortic annulus diameter ∗ | 20.5 ± 1.1 | 20.4 ± 1.2 | 20.6 ± 1.1 | 0.405 |
| Indexed annulus diameter ∗ | 11.8 ± 1.3 | 11.8 ± 1.2 | 11.8 ± 1.4 | 0.979 |
| Left ventricular ejection fraction (%) ∗ | 59.0 ± 11.6 | 59.7 ± 11.8 | 58.2 ± 11.5 | 0.558 |
| Left ventricular diastolic diameter (mm) | 46.9 ± 6.2 | 45.6 ± 5.7 | 48.2 ± 6.5 | 0.067 |
| Left ventricular systolic diameter (mm) | 30.5 ± 8.1 | 29.2 ± 7.3 | 31.9 ± 8.8 | 0.140 |
| Heart rate (beats/min) | 67 ± 12 | 67 ± 12 | 68 ± 12 | 0.947 |
| Stroke volume (ml) | 54.7 ± 14.7 | 53.9 ± 16.9 | 55.6 ± 11.7 | 0.632 |
| Maximal aortic gradient (mm Hg) | 76.6 ± 26.0 | 77.3 ± 26.6 | 75.9 ± 25.7 | 0.808 |
| Mean aortic gradient (mm Hg) | 46.0 ± 16.3 | 45.8 ± 16.4 | 46.2 ± 16.4 | 0.902 |
| Effective orifice area (cm 2 ) | 0.61 ± 0.14 | 0.58 ± 0.14 | 0.63 ± 0.13 | 0.139 |
| Indexed effective orifice area (cm 2 /m 2 ) | 0.35 ± 0.08 | 0.34 ± 0.08 | 0.36 ± 0.07 | 0.235 |
| Doppler velocity index | 0.195 ± 0.0430 | 0.196 ± 0.048 | 0.195 ± 0.038 | 0.855 |
| Pulmonary artery systolic pressure | 40.9 ± 14.9 | 41.7 ± 15.9 | 39.7 ± 13.6 | 0.596 |
| Aortic regurgitation grade | 0.498 | |||
| 0 | 15 (18.3%) | 10 (24.4%) | 5 (12.2%) | |
| 1 | 43 (52.4%) | 19 (46.3%) | 24 (58.5%) | |
| 2 | 23 (28.0%) | 11 (26.8%) | 12 (29.3%) | |
| 3 | 1 (1.2%) | 1 (2.4%) | 0 | |
| 4 | 0 | 0 | 0 | |
| Mitral regurgitation grade | 0.821 | |||
| 0 | 10 (12.2%) | 2 (4.9%) | 8 (19.5%) | |
| 1 | 35 (42.7%) | 21 (51.2%) | 14 (34.1%) | |
| 2 | 33 (40.2%) | 17 (41.5%) | 16 (39.0%) | |
| 3 | 4 (4.9%) | 1 (2.4%) | 3 (7.3%) | |
| 4 | 0 | 0 | 0 |
| Variable | CV (n = 41) | ES (n = 41) | p Value |
|---|---|---|---|
| Left ventricular ejection fraction (%) | 60.1 ± 10.2 | 57.1 ± 11.6 | 0.217 |
| Heart rate (beats/min) | 68 ± 11 | 69 ± 12 | 0.756 |
| Stroke volume (ml) | 58.3 ± 15.6 | 57.7 ± 14.5 | 0.887 |
| Stroke volume index (ml/m 2 ) | 33.9 ± 9.4 | 32.1 ± 7.6 | 0.456 |
| Maximal aortic gradient (mm Hg) | 15.0 ± 5.8 | 18.4 ± 6.9 | 0.019 |
| Mean aortic gradient (mm Hg) | 7.9 ± 3.1 | 9.7 ± 3.8 | 0.024 |
| Doppler velocity index | 0.498 ± 0.121 | 0.439 ± 0.094 | 0.025 |
| Left ventricular ejection time (ms) | 294 ± 32 | 297 ± 44 | 0.740 |
| Time to peak velocity (ms) | 77 ± 17 | 78 ± 15 | 0.830 |
| Effective orifice area (cm 2 ) | 1.58 ± 0.31 | 1.49 ± 0.24 | 0.101 |
| Indexed effective orifice area (cm 2 /m 2 ) | 0.91 ± 0.17 | 0.85 ± 0.16 | 0.080 |
| Prosthesis–patient mismatch | 0.101 | ||
| None | 27 (66%) | 18 (44%) | |
| Moderate | 10 (24%) | 19 (46%) | |
| Severe | 4 (10%) | 4 (10%) | |
| Global aortic regurgitation grade | 0.008 | ||
| 0 | 6 (15%) | 17 (42%) | |
| 1 | 19 (46%) | 15 (37%) | |
| 2 | 14 (34%) | 9 (22%) | |
| 3 | 2 (4.9) | 0 | |
| 4 | 0 | 0 | |
| ≥1 | 35 (85%) | 24 (56%) | 0.007 |
| ≥2 | 16 (39%) | 9 (22%) | 0.093 |
| Paravalvular aortic regurgitation grade | 0.001 | ||
| 0 | 6 (15%) | 25 (61%) | |
| 1 | 19 (46%) | 7 (17%) | |
| 2 | 14 (34%) | 9 (22%) | |
| 3 | 2 (5%) | 0 | |
| 4 | 0 | 0 | |
| ≥1 | 35 (85%) | 16 (40%) | 0.001 |
| ≥2 | 16 (39%) | 9 (22%) | 0.093 |
| Number of aortic regurgitation jets | 2 (1–3) | 1 (0.5–2) | 0.004 |
| Circumferential extension (%) | 8 (5–11) | 2 (0–5) | 0.001 |
| Diameter prosthesis size/diameter aortic annulus ratio | 1.28 ± 0.08 | 1.27 ± 0.07 | 0.425 |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
