Figura 1. Longitudinal mid-esophageal projection of both the aortic valve (A) and the left ventricle...

Figura 2. Coronary computed tomography angiography axial projection (A) showing significant calcific...

Figura 3. Fluoroscopic imaging in cranial LAO projection during transcatheter aortic valve implantat...

Introduction

The association between aortic valve disease and subaortic membrane (SAoM) is rare. The guidelines on the management of this entity have not been established in the current clinical practice guidelines yet. However, surgery is the treatment of choice in most cases. This is the case of a patient with severe bioprosthetic aortic valve dysfunction associated with SAoM and solved through valve-in-valve transcatheter aortic valve implantation (VIV-TAVI).

Clinical case

This is the case of a 77-year-old male patient. The patient had dyslipidemia, hypertension, was a former smoker, and had been previously treated with surgical aortic valve replacement (SAVR) with a no. 23 bioprosthetic valve. The procedure had been performed in a different center back in 2018. Two years later, in June 2020 he was admitted to our hospital with clinical signs of congestive heart failure (CHF) with functional class (FC) II of 7-month evolution with progression into FC IV 15 days prior to the patient’s consultation. The ECG revealed the presence of atrial fibrillation and left anterior fascicular block. The transthoracic echocardiogram (TTE) performed confirmed the presence of a left ventricular ejection fraction of 46%, moderate pulmonary hypertension, and a biological valve in aortic position with a significantly high antegrade gradient. The peak velocity reported was 3.3 m/seg, with an area of 1.1 cm² (0.52 cm²/m²), a mean gradient of 36 mmHg, and the presence of 2 jets of moderate aortic regurgitation (AR). The patient’s physical examination was completed with a transesophageal echocardiogram (TEE) that revealed the presence of SAoM in the sub-valvular projection with respect to the aortic valve annulus 13.8 mm away from its upper edge and 11 mm away from its lower edge that compromised 16.4 mm of the overall diameter of the left ventricular outflow tract (21 mm).

The coronary computed tomography angiography performed revealed the presence of severe calcification of the aortic valve and the ascending aorta, and severe calcification and tortuosity of the iliac-femoral arterial territory with both femoral arteries with diameters < 6 mm. The distance between the left main coronary artery and the valvular plane was estimated in 8 mm, and the distance between the right coronary artery and the valvular plane was estimated in 16 mm. The cine coronary arteriography (CCA) confirmed the occlusion of the right coronary artery, and the presence of a severe lesion in the diagonal branch.

After discussion with the heart team, it was interpreted that the clinical signs of decompensation were due to the presence of a dysfunctional aortic valve associated with SAoM. Due to the patient’s high surgical risk (EuroSCORE II, 33.73%; STS, 13.62%) the Interventional Cardiology Unit and the Cardiovascular Surgery Unit decided to solve the problem through the VIV-TAVI approach via subclavian access followed by the resolution of the SAoM through balloon valvuloplasty.

The procedure was performed under general anesthesia via left subclavian surgical access. The lesion was crossed in the valvular plane with a 0.035 in Starter™ straight guidewire (Boston Scientific, MA, United States) followed by a 6-Fr Impulse™ AL2 catheter (Boston Scientific, MA, United States). The guidewire was changed for a Confida™ guidewire (Medtronic, Minneapolis, MN, United States). The aortic valve and the SAoM were both predilated with a 20 mm balloon, and a no. 26 CoreValve™ Evolut R™ device was advanced (Medtronic, Minneapolis, MN United States) that was eventually released uneventfully. Since the patient was a carrier of a SAoM and the distance between the left main coronary artery and the valvular plane was 8 mm it was decided to proceed with a “low” release or implantation of the valve. Angiographic and echocardiographic control followed that confirmed the right positioning of the device without paravalvular regurgitation or presence of SAoM in the left ventricular outflow tract, and a maximum aortic gradient of 12 mmHg. The patient’s disease progression was favorable and uneventful, and he has remained asymptomatic to this date.

Discussion

Subaortic membrane (SAoM) is a relatively rare entity. It has been reported that its prevalence is highly variable with rates that go from 6.1% per 10 000 live births (1) to 6%-6.5% in the general population (2). It is described as an isolated defect that can also occur in patients with aortic valve disease or congenital heart disease. Its association with AR has been reported in pediatric patients, but not in patients with aortic stenosis (AoS) (3). However, a retrospective study showed a higher rate of AoS in adult patients with SAoM with a higher surgical rate for AoS compared to AR (4). A theory that may explain this behavior is that adult patients with traditional risk factors for the development of AoS can be susceptible to accelerated calcification of the aortic valve due to hemodynamic changes generated by the SAoM (5).

To this date, the current clinical practice guidelines have not established any management patterns when both entities occur concomitantly. They only describe the management options for each condition separately. According to the guidelines published back in 2020 by the European Society of Cardiology on the management of congenital heart disease in adult patients, surgery is recommended in patients with symptomatic SAoM, and a spontaneous mean gradient or induced by exercise testing > 40 mmHg or with severe AR (6). Regarding severe AR, surgery should be considered a viable option in the presence of symptoms and/or left ventricular dysfunction (7). In adult patients with SAoM and severe AoS, it has been confirmed that the predominant obstruction is found at valve level; for this reason, both management and treatment can be guided same as if it were a case of isolated AoS (8).

Despite the impulse given to the use of transcatheter aortic valve implantation (TAVI) over the last decade in patients with symptomatic AoS, its indication in patients with SAoM-related severe AoS is not included in the current clinical practice guidelines. Recently, an analysis of the STS/ACC TVT registry compared the results of 21 575 on-label TAVIs vs 2272 off-label TAVIs. Only 3 patients who were carriers of SAoM (included as an off-label indication for TAVI) were eventually treated with TAVI, with a similar 1-year mortality rate compared to the on-label TAVI group (9).

The prevalence of bioprosthetic aortic valve dysfunction associated with SAoM is still unknown. We did not find reports on the use of the VIV-TAVI approach in these cases, although the benefits of this therapy to treat isolated bioprosthetic aortic valve dysfunction were assessed in several studies that confirmed the viability and safety of the VIV-TAVI approach in patients properly selected. The mid-term results show that the patients’ hemodynamic status gets better. Also, functional results are excellent (10), which is why a IIa recommendation has been granted in the current clinical practice guidelines (7).

Conclusion

The association between severe AoS and SAoM is rare. TAVI is a safe and valid option in high-risk surgical patients in this type of cases. The VIV-TAVI approach is viable over a new surgery in patients with previous biologic aortic valve replacement.

1. Kitchiner D, Jackson M, Malaiya N, Walsh K, Peart I, Arnold R. Incidence and prognosis of obstruction of the left ventricular outflow tract in Liverpool (1960–91): a study of 313 patients. Br Heart J 1994;71:588-95.

2. Van der Linde D, Takkenberg JJ, Rizopoulos D, Heuvelman HJ, Budts W, van Dijk AP, et al. Natural history of discrete subaortic stenosis in adults: a multicentre study. EurHeart J 2013;34:1548-56.

3. Stout KK, Daniels CJ, Aboulhosn JA, Bozkurt B, Broberg CS, Colman JM, et al. 2018 AHA/ACC guideline for the management of adults with congenital heart disease. J Am CollCardiol 2018.

4. Laksman ZW, Silversides CK, Sedlak T, Samman AM, Williams WG, Webb GD, et al. Valvular aortic stenosis as a major sequelae in patients with pre-existing subaortic stenosis: changing spectrum of outcomes. J Am CollCardiol 2011;58:962-5.

5. Kamath AR, Pai RG. Risk factors for progression of calcific aortic stenosis and potential therapeutic targets. Int J Angiol 2008;17:63-70.

6. Baumgartner H , De Backer J, Babu-Narayan SV, Budts W, Chessa M, et al. 2020 ESC Guidelines for the management of adult congenital heart disease. EurHeart J 2020 Aug 29.

7. Nishimura RA, Otto CM, Bonow RO, et al. 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2017;135(25):e1159-e1195.

8. McGregor PC, Manning P, Raj V, et al. Does Presence of Discrete Subaortic Stenosis Alter Diagnosis and Management of Concomitant Valvular Aortic Stenosis?CASE (Phila). 2019;3(2):77-84.

9. Hira RS, Vemulapalli S, Li Z, et al. Trends and Outcomes of Off-label Use of Transcatheter Aortic Valve Replacement: Insights From the NCDR STS/ACC TVT Registry. JAMA Cardiol. 2017;2(8):846-854.

10. Hirji SA, Percy ED, Zogg CK, et al. Comparison of in-hospital outcomes and readmissions for valve-in-valve transcatheter aortic valve replacement vs. reoperative surgical aortic valve replacement: a contemporary assessment of real-world outcomes. EurHeart J. 2020;41(29):2747-2755.

Para descargar el PDF del artículo
Valve-in-valve transcatheter aortic valve implantation in patient with severe bioprosthetic aortic valve dysfunction and subaortic membrane

Haga click aquí