Figure 1. Transseptal puncture. B. Surgical bioprosthetic valve pierced with a 0.035 in guidewire wi...

Figure 2. View and computed axial tomography with contrast and cardiac gating showing the correct po...

Introduction

Mechanical heart valves are the most lasting ones. However, their thrombogenic potential should be counteracted with the use of anticoagulant drugs. To prevent the risks of valve thromboembolism or hemorrhages associated with the use of anticoagulants, biological valves have become available. However, between 20% and 30% of the patients treated with biological mitral valves should be reoperated due to the degeneration of these valves at follow-up (1).

Valve reinterventions and replacements are the standard of choice for the management of severely degenerated heart valves. However, reinterventions are often associated with a high risk, above all, in elderly patients with comorbidities (2).

The development and use of valvular therapies via catheter approach have also brought us an endless number of therapeutic alternatives for high-surgical risk patients. Transcatheter mitral valve replacement for degenerative mitral valve disease (mitral ViV) has proven to be a safe and effective procedure especially via transseptal access (TSA). Through this access, the transcatheter heart valves (THV) most widely used are the aortic SAPIEN XT/SAPIENT S3 valves from Edwards Lifesciences (Irvine, CA, United States) (3).

This is a case of a mitral ViV via TSA using the SAPIEN XT balloon-expandable aortic valve in an elderly woman with severe mitral regurgitation due to a degenerative surgical bioprosthetic valve (SBV) implanted 8 years ago. As far as we know, this is the very first fully transcatheter case ever performed and reported in Argentina.

Case report

This is the case of a 79-year-old woman with high-surgical risk (Euro Score 16%, and STS 12%) with heart failure (HF) with severe mitral regurgitation due to a degenerated porcine SBV model HFS – Foc Medical No. 27 implanted 8 years ago. The patient’s comorbidities were severe coronary artery disease that required coronary artery bypass graft (CABG) together with mitral valve (MV) replacement, severe pulmonary hypertension (mean 55 mmHg), systemic arterial hypertension, moderately impaired kidney function (creatinine clearance levels of 50 mL/min), and permanent atrial fibrillation. The patient’s clinical signs were NYHA [New York Heart Association] functional class IV dyspnea with multiple hospital admissions due to decompensated HF over the last year.

The transthoracic echocardiography performed prior to the procedure revealed a thickened SBV with a flail leaflet and severe regurgitation with 1 jet oriented towards the posterolateral wall of the atrium and another jet towards the interatrial septum. EROA, 0.45 cm2; mitral annulus, 30 mm; estimated ejection fraction, 60%; slightly dilated left atrium (area of 22 cm2).

The computed axial tomography (CAT) scan with contrast and cardiac gating performed revealed an internal valvular diameter of 480 mm2. The risk of left ventricular outflow tract (LVOT) obstruction was very low (angle of 110 degrees, new outflow tract of 570 mm2), and the interatrial septum (IAS) remained intact. The presence of thrombus at left atrial appendage and femoral vein level was ruled out. Iliac veins like the inferior vena cava (IVC) remain patent. Both venous bridges are patent. The left main coronary artery and left anterior descending coronary artery remain patent and without significant lesions.

The case was discussed with the heart team, and it was agreed that the mitral ViV would be the best option for the patient.

Procedure

It was decided to use a No. 26 SAPIEN XT aortic THV with a volume of 2 more cubic centimeters compared to the nominal volume for proper anchoring and implantation, and to avoid leak or migration. Implantation was decided on a 70/30 ratio with respect to the valvular annulus (70% ventricular; 30% atrial).

The procedure was performed at the cath lab with cardiac surgery equipment and under conscious sedation.

Two femoral venous accesses were attempted (a right one for the device and a left one for the temporary pacing wires) followed by one 5-Fr arterial access to advance a pigtail catheter towards the left ventricle (LV) for monitorization purposes and angiographic follow-up.

Puncture via TSA (figure 1) was performed under transesophageal echocardiography guidance to achieve precision and safety. The pullback technique was used from the superior vena cava towards the right atrium. Puncture was performed posterior/inferior/medially 3 cm away from the prosthetic view with an 8-Fr catheter (Mullins Transeptal Catheter Introducer Set, Medtronic, AVE, Ireland) and a puncture needle (Brockenbrough) with a modified curve no 1. After perforating the interatrial septum (IAS), a total of 100 IU x kg of heparin were administered. Then, two 0.035 in guidewires were advanced towards the left atrium (LA), one of them a rigid guidewire. An 8-Fr medium curved deflectable catheter (Agilis NxT steerable transseptal sheath St. Jude Medical, Saint Paul, MN, United States) was mounted on the latter. Another 5-Fr pigtail catheter was mounted on the other 0.035 in guidewire to monitor atrial pressure.

The deflectable catheter was used to run through the prosthesis with a J-shaped tip 0.035 in guidewire on which a pigtail catheter was mounted and then advanced towards the LV on which a 2.60-meter extra rigid guidewire was placed [Meier Backup wire (Boston Scientific)]. After extracting the catheter, a 12 mm x 40 mm peripheral balloon (Boston Scientific) was mounted on this guidewire and then advanced. Balloon was used to dilate the IAS at 14 atm for 40 seconds to facilitate the advancement of the valve through the IAS.

Peripheral balloon wad removed, and an 18-Fr introducer sheath was advanced towards the IVC. Afterwards, the SAPIEN XT valve was pre-mounted on the rigid guidewire for antegrade access. The valve was mounted on the balloon delivery system and then advanced towards the LA to later overlap it with the MV that should be replaced. Initially, the system is introduced without deflection and oriented 120º clockwise with respect to its aortic position. Once the IAS has been crossed, the system is deflected at between 50% and 75%.

The THV is positioned and slowly manually inflated under a fast pacemaker (140 beats per minute).

After implantation, the delivery system was removed towards the IVC and transvalvular gradient was measured with pigtail catheters (in LA and LV) resulting in 8/3 mmHg (4). Left ventriculogram was performed, leaks were ruled out, and catheters were removed. Compression hemostasis was performed and left femoral access (venous) was closed. Also, a knot was adjusted in a figure-of-eight suture in the subcutaneous tissue.

The patient had NYHA functional class I with no hospital admissions since implantation at 24-month follow-up. Both the valvular area and the gradients remained stable. No valvular or paravalvular leaks were reported. The CAT scan with contrast and cardiac gating confirmed the perfect apposition and expansion of the SAPIEN XT into the SBV (figure 2).

Discussion

The first successful mitral ViV procedure was performed via transapical access (TA) (4), and to this day, it is still the most widely used access of all because it provides direct, coaxial, and reproducible access to the mitral valve (5).

TA is less invasive, does not require general anesthesia, and causes no apical, thoracic or pulmonary damage. Also, it promotes fast recovery times and short hospital stays (1, 6, 7). This access is feasible partly because of the orientation capabilities that the handle provides that give the device and its new S3/Ultra generations special capabilities for proper coaxial orientation (4).

SBV are often large and circular, which is perfect for replacement with implantation of a SAPIEN balloon-expandable valve, thus providing an excellent fit for this valve into the old one with good results (basically thanks to the low gradient and rate of paravalvular leak). The clinical benefit achieved is surprising (8) as it was confirmed in our patient even 2 years after the procedures.

The first step during patient selection is to identify the size and model of the SBV. The CAT scan can help identify both the size and the model, plan implantation, and avoid complications (LVOT obstruction). Afterwards, the size of the THV that will eventually replace the dysfunctional valve is selected. There is an app available for smartphones that can help throughout this process (9).

Two series, one of 17 patients and the other of 4 proved the feasibility of performing mitral ViV through venous access via TSA. The rates of success were 82%, and 100% respectively (1,7).

A multicenter registry recently published including 322 patients (TSA, and TA) describes very satisfactory results with technical success rates of 94.4%, and procedural success rates of 74%. The rate of postoperative complications was only 2.2% while the 30-day mortality rate was 6.2% (10), which is so good if we think that the in-hospital mortality rate of a mitral replacement reintervention goes from 9% up to 12.6% (11). Another recent registry shows the results of transcatheter mitral valve replacement via transseptal access in 1326 patients reporting success rates of up to 97.1%, and in-hospital mortality rates of 1.8% via transseptal access (vs 4.4% in TA) (12). This mortality rate goes up to 5% at 30-day follow-up, and 15.8% at 1-year follow-up, which reveals the cardiovascular residual risk of this high-risk population.

Conclusions

High or extremely high-surgical risk patients can benefit from transcatheter degenerated mitral valve replacement via transseptal access. This minimizes complications, shortens hospital stay, and reduces immediate mortality and at follow-up.

1. Bouleti C, Fassa AA, Himbert D, et al. Transfemoral implantation of transcatheter heart valves after deterioration of mitral bioprosthesis or previous ring annuloplasty. JACC Cardiovasc Interv 2015;8(1 Pt A):83-91.

2. Webb JG, Wood DA, Ye J, et al. Transcatheter valve-in-valve implantation for failed bioprosthetic heart valves. Circulation 2010;121(16):1848-57.

3. Eleid MF, Cabalka AK, Williams MR, et al. Percutaneous Transvenous Transseptal Transcatheter Valve Implantation in Failed Bioprosthetic Mitral Valves, Ring Annuloplasty, and Severe Mitral Annular Calcification. JACC Cardiovasc Interv 2016;9(11):1161-74.

4. Cheung A, Webb JG, Barbanti M, et al. 5-year experience with transcatheter transapical mitral valve-in-valve implantation for bioprosthetic valve dysfunction. J Am Coll Cardiol 2013;61(17):1759-66.

5. Cheung A, Webb JG, Wong DR, et al. Transapical transcatheter mitral valve-in-valve implantation in a human. Ann Thorac Surg 2009;87(3):e18-20.

6. Wang DD, Eng MH. Transseptal Transcatheter Mitral Valve Replacement for Post-Surgical Mitral Failures. Interv Cardiol Review 2018;13(2):77-80.

7. Coylewright M, Cabalka AK, Malouf JA, et al. Percutaneous mitral valve replacement using a transvenous, transseptal approach: transvenous mitral valve replacement. JACC Cardiovasc Interv 2015;8(6):850-7.

8. Murdoch DJ, Webb JG. Transcatheter valve-in-valve implantation for degenerated surgical bioprostheses. J Thorac Dis 2018;10(Suppl 30):S3573-S7.

9. Bapat V. Valve-in-valve apps: why and how they were developed and how to use them. EuroIntervention 2014;10 Suppl U:U44-51.

10. Yoon SH, Whisenant BK, Bleiziffer S, et al. Outcomes of transcatheter mitral valve replacement for degenerated bioprostheses, failed annuloplasty rings, and mitral annular calcification. Eur Heart J 2019;40(5):441-51.

11. Maisano F, Taramasso M. Mitral valve-in-valve, valve-in-ring, and valve-in-MAC: the Good, the Bad, and the Ugly. Eur Heart J 2019;40(5):452-5.

12. Whisenant B, Kapadia SR, Eleid MF, et al. One-Year Outcomes of Mitral Valve-in-Valve Using the SAPIEN 3 Transcatheter Heart Valve. JAMA Cardiol 2020;5(11):1245-52.

Para descargar el PDF del artículo
Follow-up of a patient with transcatheter degenerated mitral valve replacement via transseptal access. First case report in Argentina

Haga click aquí