Methods

The study population included patients with documented BAVs who were treated using TAVI with the MCS. Preoperative screening included clinical evaluation, with a specific analysis of the anatomy of the BAV. Otherwise, screening did not differ from standard TAVI. Then, a heart team evaluated the risk profiles of the patients and reached a consensus regarding the method of treatment.

The diagnosis of BAV was based on short-axis imaging of the aortic valve using transthoracic or transesophageal echocardiography. The diagnosis of BAV was confirmed in the presence of only 2 commissures delimiting only 2 aortic leaflets. BAVs were classified on the basis of the presence (type 1) or absence (type 0) of raphe.

AS severity was assessed using the transaortic mean gradient and the aortic valve area. The amount and distribution of calcification were noted. Associated aortic regurgitation (AR) was evaluated according to published guidelines. The aortic annulus was measured at the insertion of the aortic cusps. Multislice computed tomography confirmed the diagnosis and assessed the type of BAV, the amount and distribution of calcification, and the aortic diameters, including the annulus, sinuses of Valsalva, sinotubular junction, and ascending aorta; the calcium score was calculated as previously described. The technical aspects of TAVI using the MCS have been previously described. Procedures were performed using either the retrograde transfemoral or left subclavian approach. TAVI was performed either under local anesthesia with conscious sedation or under general anesthesia with transesophageal echocardiographic guidance. The 18Fr transfemoral arterial access was obtained percutaneously using the Prostar 10 F XL (Abbot Vascular Devices, Redwood City, California). The subclavian procedure was performed using surgical cut-down access and closure. Balloon predilatation was performed using an undersized balloon, usually 20 or 22 mm in diameter.

Postoperatively, patients received a combination of aspirin and clopidogrel for 3 months (then aspirin or clopidogrel alone) or clopidogrel and oral anticoagulation if otherwise indicated.

Clinical follow-up, transthoracic echocardiography, and when possible multislice computed tomography were performed before discharge. Several parameters were specifically assessed: the mitral overlap by the MCS (the distance between the insertion of the anterior mitral leaflet and the ventricular end of the prosthesis), an ellipticity index of the prosthesis (the ratio of small prosthetic diameter to large prosthetic diameter at the levels of the native annulus and of the hinge points of prosthetic leaflets, located 12 mm above the ventricular end of the MCS), and the implantation depth of the prosthesis (the distance between the noncoronary cusp and the ventricular end of the prosthesis). Adverse events were prospectively recorded. Thirty-day, 6-month, and 1-year medical visits and transthoracic echocardiography were performed at our institution or by the patients’ own cardiologists, and data were collected by telephone.

Device success and end point definitions were the standardized definitions of the consensus report from the Valvular Academic Research Consortium.

Data are expressed as mean ± SD or as median (interquartile range). Statistical analysis was performed using JMP version 7.0.1 Statistical Discovery (SAS Institute Inc., Cary, North Carolina).

Results

From January 2009 to January 2012, of the 316 patients who underwent TAVI, 15 (5%) had documented BAVs and received MCS. Patients’ clinical baseline characteristics are listed in Table 1 . The mean age was 80 ± 10 years; their mean Society of Thoracic Surgeons risk score and logistic European System for Cardiac Operative Risk Evaluation score were 8 ± 5% and 17 ± 11%, respectively.

Echocardiographic findings were as follows: mean aortic valve area 0.8 ± 0.3 cm ² (0.5 ± 0.1 cm ² /m), mean aortic gradient 60 ± 19 mm Hg, mean left ventricular ejection fraction 52 ± 13%, and mean aortic annular diameter 24 ± 2 mm. Dimensions of the aorta were 25 ± 2, 36 ± 3, 32 ± 4, and 37 ± 3 mm at the level of the annulus, the sinuses of Valsalva, the sinotubular junction, and the ascending aorta, respectively. The presence of a raphe was observed in 10 patients. Two patients had no raphe. The type of BAV was uncertain in 3 patients. Calcifications were qualified as moderate in 7 and severe in 8 and were predominantly located on the raphe in 3 and on the free edges of the cusps in 6 and were diffuse in 6. Associated AR was present in 8 patients (grade 1+ in 4 patients and grade 2+ in 4 patients).

Multislice computed tomographic findings are listed in Table 2 . The mean annular diameter was calculated at 26 ± 2 mm. Mean distances between the aortic annulus and the left and right coronary ostia were 14 ± 3 mm (range 11 to 20) and 15 ± 4 mm (range 8 to 22), respectively. The maximal ascending aortic diameter was 37 ± 4 mm. Overall, findings were consistent with those from echocardiographic imaging. Type 1 BAVs were found in 10 patients and type 0 BAVs in 2 ( Figure 1 ). In 3 cases, the type of BAV was not identifiable, because of extensive valve calcification. The calcium score was 4,553 ± 1,872 arbitrary units.

Multislice computed tomographic imaging of BAVs: (left) type 1 BAV (one raphe); (right) type 0 BAV (no raphe).

Procedures were performed by transfemoral access in 14 patients and by subclavian access in 1. General anesthesia was used in 3 patients. In the latter, 2-dimensional and 3-dimensional transesophageal echocardiography was useful for guiding prosthesis deployment. The 29-mm MCS was implanted in 13 patients and the 26-mm MCS in 2. The AccuTrack system was used in 9 patients. The procedure was successful in 14 patients. There was no intraprocedural death. In the first patient, the MCS was implanted too low in an extensively calcified BAV, resulting in 3+ paraprosthetic AR; the patient developed acute respiratory distress a few hours after implantation. Emergency surgical aortic valve replacement was carried out, but the patient did not survive. Despite asymmetric expansion of the MCS on fluoroscopy in several patients ( Figure 2 ), immediate hemodynamic performance of the prostheses was satisfactory in 13 patients, with paraprosthetic or central AR grade ≤1+ and transprosthetic gradient <20 mm Hg ( Figure 3 ).

Fluoroscopic imaging of a deployed MCS in a BAV. Asymmetric deployment of an MCS in patient 6: (left) left anterior oblique projection; (right) right anterior oblique projection.

Hemodynamic result in patient 6 after asymmetric deployment of an MCS in a BAV: (left) immediate mean gradient 9 mm Hg (invasive assessment); (right) predischarge mean gradient 15 mm Hg (transthoracic echocardiography).

The median hospital stay from procedure to discharge was 9 days (interquartile range 8 to 10). The 30-day combined safety end point rate was achieved in 14 patients (93%). There was 1 in-hospital death, described earlier; there was no other major adverse events. Permanent pacemakers were required in 6 patients. On predischarge transthoracic echocardiography, the mean transprosthetic gradient was 11 ± 4 mm. Mild AR (1+) was observed in 13 patients, and 1 had AR 2+. The mean mitral overlap by the MCS was 6 ± 4 mm, with no impact on the function of the mitral valve. In the 11 patients who underwent post-TAVI multislice computed tomography, mean prosthetic ellipticity indexes were 0.7 ± 0.2 and 0.8 ± 0.2 at the levels of the native annulus and of the prosthetic leaflets, respectively. An ellipticity index <0.8 at the level of the leaflets was observed in only 2 patients: it was 0.7 in patient 12, who had a marked elliptical shape of the prosthesis at the level of the annulus (ellipticity index 0.5; Figure 4 ), and 0.4 in patient 14, who had the most extensive valvular calcification observed in the series, with a calcium score of 7,772 arbitrary units. On average, the implantation depth was 7 ± 5 mm (range 0 to 15). In the 3 patients who had deep-seated MCS (implantation depth >10 mm), there was no difference between the ellipticity indexes calculated at the level of the annulus and of the prosthetic leaflets ( Table 3 ).

Multislice computed tomographic imaging of asymmetric deployment of an MCS in a BAV in patient 6: (Top) longitudinal view; (bottom left) transverse view at the level of the functioning prosthetic leaflets (supra-annular); (bottom right) transverse view at the level of the native aortic valve annulus.

Table 3

Predischarge echocardiographic and computed tomographic findings

Patient	Transthoracic Echocardiography
			AR			Computed Tomography
	Mean Gradient (mm Hg)	Peak Gradient (mm Hg)	Central	Paravalvular	Mitral Overlap ⁎	Ellipticity Index, Aortic Annular Level †	Ellipticity Index, Prosthetic Leaflets Level †	Implantation Depth (mm) ‡
1	16	28	0	+	6	0.8	0.9	7
2	9	19	0	+	8	0.8	0.9	9
3	15	26	0	+	8	—	—	—
4	—	—	0	+	—	—	—	—
5	6	10	0	+	—	—	—	—
6	9	28	0	0	0	0.5	0.8	0
7	8	27	0	+	1	0.9	1.0	2
8	12	28	0	+	7	0.8	0.9	7
9	14	23	0	+	9	0.8	0.8	13
10	5	13	0	+	10	0.7	0.8	7
11	11	16	0	+	6	0.9	0.9	11
12	10	32	+	+	0	0.5	0.7	0
13	8	16	0	+	7	—	—	—
14	18	32	0	+	5	0.4	0.4	7
15	10	26	0	+	14	0.9	0.8	15

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

1. Comparison of Circadian Rhythm Patterns in Tako-tsubo Cardiomyopathy Versus ST-Segment Elevation Myocardial Infarction
2. Meta-Analysis of Effect of Dipeptidyl Peptidase-4 Inhibitors on Cardiovascular Risk in Type 2 Diabetes Mellitus
3. Serum 25-Hydroxyvitamin D Concentration and Mortality from Heart Failure and Cardiovascular Disease, and Premature Mortality from All-Cause in United States Adults
4. Usefulness of Doppler Echocardiographic Left Ventricular Diastolic Function and Peak Exercise Oxygen Consumption to Predict Cardiovascular Outcomes in Patients With Systolic Heart Failure (from HF-ACTION)

Stay updated, free articles. Join our Telegram channel

Join