Transcatheter Aortic Valve Replacement for Bicuspid Aortic Insufficiency After Valve-Sparing Aortic Root Replacement.

Bicuspid aortic insufficiency (BAI) patients with root aneurysm often require aortic valve and root replacement in a composite procedure. The valve-sparing root replacement (VSARR) procedure is aimed at preserving the native valve when possible. This case highlights a successful transcatheter aortic valve replacement procedure in a BAI patient previously treated with VSARR. (Level of Difficulty: Intermediate.).

A 59-year-old woman presented with new progressive fatigue, dyspnea on exertion, and shortness of breath at rest. She was known to have a congenital bicuspid aortic valve (BAV) and to have previously undergone aortic surgery involving the ascending aorta because of an aortic aneurysm.

Learning Objectives

To be familiar with the epidemiology, pathophysiologic aspects, and natural history of bicuspid aortic valve disease.

To explore the treatment options for bicuspid aortic insufficiency patients with root aneurysms.

To discuss the preprocedural dilemmas of matching and sizing a transcatheter heart valve in bicuspid aortic insufficiency patients with root replacement.

Medical History

The patient's medical history included controlled hypertension, asthma, hyperthyroidism, rheumatoid arthritis, and breast cancer treated by surgical lumpectomy and mediastinal radiation.

In 2014, the patient experienced daily chest pain and effort-related dyspnea. Transthoracic echocardiography (TTE) demonstrated a bicuspid aortic valve and mild to moderate aortic insufficiency (AI). A computed tomographic (CT) angiogram revealed a calcified raphe with a fusion of the left and right coronary cusps and an ascending aortic aneurysm at a 4.5-cm maximal diameter. The patient underwent a valve-sparing aortic root replacement (VSARR), known as a David procedure, with use of a 26-mm prosthetic aortic root graft and a 26-mm prosthetic annular graft (Figure 1). The valve was decalcified and partially repaired with a free-edge plication with one suture. TTE after the procedure indicated a remaining mild to moderate AI with eccentric and posteriorly directed jet.

Figure 1

Computed Tomographic Angiographic View of Ascending Aorta Before and After Valve-Sparing Aortic Root Replacement Surgery

The white arrow points to aortic root graft.

Differential Diagnosis

The following diagnoses were considered: coronary artery disease, progressive valvular dysfunction, arrhythmias, and heart failure.

Coronary angiography indicated a patent coronary artery, and 24-hour Holter monitoring demonstrated extra beats and no arrhythmias. TTE and transesophageal echocardiography demonstrated an aortic valve coaptation defect, a pressure half-time of 196 ms, and holodiastolic flow reversal in the proximal abdominal aorta, indicating a more severe AI (Figure 2). The left and right ventricles were of normal size and function.

Figure 2

Significant Aortic Insufficiency Seen on Midesophageal Transesophageal Echocardiographic Views

Management

A heart team recommended transcatheter aortic valve replacement (TAVR) over redo cardiothoracic surgery, considering the surgical risk, the patient's age, previous sternotomy, previous mediastinal radiation, and the patient’s preference.

Cardiac reconstructed CT confirmed a type 1 bicuspid aortic valve and a raphe between fused left and right cusps (Figure 3). The annular measurement indicated a perimeter of 73.2 mm, an area of 403.9 mm2, and a mean diameter of 22.1 mm. The neocoronary ostia were located 18.0 mm (for the right coronary artery) and 15.7 mm (for the left coronary artery) above the annulus. The left ventricular outflow tract (LVOT) area measured 475 mm2, and the sinus of the Valsalva area (SOV) was 642 mm2. The calcium score, measured over the annulus area using an 850 Hounsfield unit cutoff, indicated a small amount (0.1 mm3) of residual calcium (Figure 4). The right femoral artery was accessible with a minimal lumen diameter of 6.3 × 6.5 mm measured at the right external iliac artery.

Figure 3

Type 1 Bicuspid Aortic Valve in Various Imaging Modalities

Figure 4

Preprocedural Reconstructed Computed Tomographic Measurements

Preprocedural dilemmas were mainly focused on the choice between the 23- or 26-mm balloon expandable Sapien-3 (Edwards Lifesciences) and the 29-mm self-expanding Evolut-PRO+ devices (Medtronic). We considered various parameters such as the actual annular diameter, graft diameter and length, neocoronary ostia height, SOV and LVOT areas, the lack of significant calcification, and the desired effective orifice area to avoid patient–prosthesis mismatch (indexed effective orifice area [EOA] of 0.93 for Sapien-3 and 1.16 for Evolut-PRO+).

Based on the preprocedural CT measurements, both transcatheter heart valves (THVs) were found to be suitable. We decided to use the 26-mm balloon-expandable Sapien-3 THV over a self-expandable THV, mainly considering future coronary access given the patient's age and the lack of calcium distribution over the annulus (1). We successfully deployed the THV over the prosthetic graft, using a standard TAVR technique via transfemoral approach (Figure 5).

Figure 5

Fluoroscopic View During Transcatheter Aortic Valve Replacement

Solid yellow arrow points to fully expandable Sapien-3 transcatheter heart valve. Open yellow arrow points to tip of a right ventricle temporary pacemaker. Red asterisk points over the left main coronary artery.

Discussion

BAV is among the most common congenital heart abnormalities seen in the adult population, affecting 1% to 2% of adults worldwide; men constitute about 70% to 80% of the cases (1). These patients often exhibit various anatomic and functional changes, such as accelerated calcification and valvular stenosis, coronary artery anomalies, and coronary artery disease. BAV aortopathy is a term coined to describe the high prevalence of aortic dilation, aneurysm, and dissection seen in BAV patients (2).

Over the past years, a modified surgical technique offers BAV patients with root aneurysms to replace the dilated segment while preserving the valvular components (3). The VSARR was associated with lower surgical complications such as heart block and cerebral hemorrhage and had a higher survival rate than the traditional Bentall surgical procedure, which also uses replacement of the aortic valve (4).

TAVR is the criterion standard for aortic stenosis patients across all risk groups, and the ongoing experience over the past decade encourages centers to include BAV patients with aortic stenosis. The initial results are promising and show similar outcomes in comparison with tricuspid TAVR patients (5, 6).

Nowadays, SAVR remains the treatment of choice for pure AI bicuspid patients because these patients usually present with larger annular size and insufficient calcification for THV anchoring, making TAVR more challenging.

Recently, a new nonrandomized large-scale study found no significant difference in in-hospital mortality between SAVR and TAVR in AI patients (7), which adds to numerous additional promising data and hope for AI patients.

BAI patients after root replacement make the percutaneous approach even more challenging. Choosing a proper THV should be balanced with the desired EOA, future coronary access, native annulus size, and graft morphology. The use of TAVR in high-risk patients with severely reduced left ventricular function, lack of aortic valve calcification, and significantly large annular size should be limited until further data support its efficacy and safety. Given the limited data of TAVR on long-term outcomes in BAV patients, TAVR may be considered in high-risk patients in whom VSARR has failed.

Our case highlights the need, the feasibility, and the dilemmas of the TAVR procedure in patients with failed VSARR and patients with bicuspid aortic regurgitation.

Follow-Up

Post-TAVR echocardiography indicated a well-seated THV with normal leaflet motion and a mean gradient of 6 mm Hg. There was no significant central aortic insufficiency or paravalvular leak (Video 1).

The Doppler-velocity index was 0.45, and the neoeffective orifice area (EOA) was 1.6 cm2/m2. The patient was discharged 2 days after the procedure feeling much better without dyspnea or shortness of breath. A 30-day post-TAVR CT indicated an annular area of 542.9 mm2, a mean diameter of 26.3 mm, and patency of the coronary ostia (Figure 6).

Figure 6

Reconstructed Computed Tomographic and Echocardiographic View 30 Days After Transcatheter Aortic Valve Replacement

Conclusions

Patients with BAV exhibit valvular dysfunction and aortic root aneurysms and have been traditionally treated with the replacement of aortic components, including replacement of the aortic valve with a prosthetic valve. Nowadays, with the ongoing use of TAVR in BAV patients and the evolution of the valve-sparing aortic root replacement technique, patients can also have a minimally invasive therapeutic option and lifelong freedom from the use of anticoagulant agents. Our case highlights this clinical scenario, the periprocedural dilemmas, and the feasibility of the procedure.

Funding Support and Author Disclosures

Dr. Makkar has received grant support from Edwards Lifesciences Corporation; is a consultant for Abbott Vascular, Cordis, and Medtronic; and holds equity in Entourage Medical. Dr Chakravarty is a consultant, proctor, and speaker for Edwards Lifesciences and Medtronic; is a consultant for Abbott Lifesciences; and is a consultant and speaker for Boston Scientific. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.