A staged approach to transcatheter aortic valve implantation and mitral valve-in-valve implantation for a degenerated bioprosthesis in a high-risk patient

Abstract

Recently, small case series have described the successful off-label use of transcatheter valve implantation in patients with degenerated bioprosthetic valves in the mitral position. We report here the case of a 78-year old female patient who underwent transcatheter aortic valve implantation for severe aortic stenosis and transapical valve-in-valve implantation for a degenerated mitral bioprosthesis. There was no evidence of intraprosthetic regurgitation and/or paraprosthetic leakages on control angiography and transoesophageal echocardiography. The postoperative course was uneventful. Following accurate patient selection and evaluation by an experienced multidisciplinary team, the transcatheter approach to double-valve implantation in the aortic and mitral positions may represent a viable treatment option for those high-risk patients who would otherwise be inoperable. We preferred a two-step approach, considering a single procedure to be high-risk.

INTRODUCTION

Transcatheter aortic valve implantation (TAVI) has increasingly become the treatment of choice for native aortic valve disease in high-risk patients, but it is also gaining attention for the replacement of degenerated aortic bioprostheses. A few case reports as well as a review are already available in the literature [1]. More recently, however, small case series have described the successful off-label use of transcatheter valve implantation in patients with degenerated bioprosthetic valves in the mitral position [2].

As the population ages, a growing number of older patients undergo heart valve replacement surgery. As a consequence, it is likely that degeneration of implanted valve bioprostheses will become more frequent in the future, requiring second-stage interventions. Transcatheter valve implantation may therefore represent a novel alternative therapeutic strategy also in patients with prior mitral valve replacement.

We report here the case of a 78-year old female patient who underwent TAVI for severe aortic stenosis and transapical valve-in-valve implantation for degenerated mitral bioprosthesis. We preferred a staged approach, considering a single procedure to be high-risk.

CASE REPORT

The patient was transferred to our department from a regional hospital, where she was admitted for heart failure and treated with intensive diuretic therapy, resulting in worsening renal function. She was referred for surgical/interventional evaluation. On admission, she was in New York Heart Association (NYHA) class III, and had peripheral oedema and bilateral pleural effusion. She was admitted to the intermediate care unit and was treated with face mask oxygen therapy, bilateral pleurocentesis, kidney protective therapy and negative fluid balance via continuous veno-venous hemofiltration with continuous monitoring of vital parameters.

Her medical history included degenerative mitral regurgitation of rheumatic aetiology, for which she underwent mitral valve replacement with a 31-mm Carpentier-Edwards bioprosthesis 9 years previously. Echocardiography revealed a degenerated pericardial bioprosthesis with severe mitral stenosis (orifice area <1.2 cm²) associated with calcific aortic stenosis (orifice area <1 cm², maximum/minimum gradient 69/44 mmHg). Left ventricular ejection fraction (Simpson's rule) was 40%.

EuroSCORE II was calculated to be 32.36% (78-year old female, severe renal failure with creatinine clearance <50 ml/min, prior cardiac surgery, combination corticosteroid and bronchodilator therapy, NYHA class III, left ventricular ejection fraction 40%, pulmonary artery pressure 48 mmHg, urgent indication and need for double-valve implantation). The estimated risk for surgery and anaesthesia was judged to be at an unacceptable or marginal level. The preoperative risk was therefore re-assessed by entering all risk factors in the EuroSCORE model, but replacing ‘double procedure’ with ‘single non-CABG procedure’. A value of 21.7% was obtained. The patient was deemed eligible for TAVI, and she was informed of the eventual risks related to the procedure. A recent case report describes both TAVI procedures performed simultaneously [3]. After evaluation by an experienced multidisciplinary team, we decided to perform the procedure in two steps, considering a single procedure to be high-risk for a patient with a very high logistic EuroSCORE.

In September 2011, TAVI was performed via the transfemoral approach in a hybrid operating room. After balloon aortic valvuloplasty, a 23-mm Edwards Sapien XT valve (Edwards Lifesciences, Irvine, CA, USA) was successfully implanted. There was no evidence of intraprosthetic regurgitation and/or paraprosthetic leaks on control angiography and transoesophageal echocardiography. The postoperative course was uneventful, and the patient was discharged to a rehabilitation facility on postoperative day 22. She received exercise and respiratory therapy for 3 weeks.

In December 2011, she was readmitted to our department for elective transcatheter valve-in-valve implantation. She was in NYHA class II and had a EuroSCORE of 14.32%. She provided informed consent for the off-label procedure. Transcatheter valve implantation was performed via the transapical approach in a hybrid operating room, using a 29-mm Edwards Sapien XT valve. No procedure-related complications occurred, and angiographic and transoesophageal echocardiographic imaging did not show any leakage. X-ray images also confirmed device stability (Fig. 1). She was transferred to the surgical ward on the first postoperative day, and she was discharged on postoperative day 9 after an uneventful hospital stay.

Figure 1:

A radiographic image obtained after the second valve procedure showing the 23-mm Edwards Sapien XT valve in the aortic position and the 29-mm Edwards Sapien XT valve in the mitral position within the degenerated 31-mm Carpentier-Edwards bioprosthesis.

After 3 months, mean aortic transprosthesis gradient was 8 mmHg; effective orifice area was 1.6 cm². The post-procedural mean mitral transprosthesis gradient was 7 mmHg.

DISCUSSION

The current case report brings up two main considerations. The first relates to the new risk model EuroSCORE II, launched in September 2011 at the EACTS meeting in Lisbon. Whether EuroSCORE II is easy to use and superior to the previous version in determining preoperative risk warrants further confirmation. However, the expected mortality in this patient would have been 49.57% if we had used EuroSCORE I, and the patient would have been deemed inoperable. Our case highlights the potential advantages of using EuroSCORE II that, among operation-related factors, includes the new variables ‘double procedure’ and ‘single non-CABG procedure’.

The second consideration concerns the clinical implications of transcatheter valve implantation in the mitral position. The feasibility of such an approach has already been demonstrated in recent reports and small case series [2], even in patients with prior mitral valve ring annuloplasty [4]. Notwithstanding the technical success achieved, a number of postoperative complications may occur that call for careful patient selection [2]. Interestingly, the experimental data of Walther et al. [5] showed that valves designed specifically for the aortic position demonstrate excellent hydrodynamic performance. These encouraging results may lead to the design and application of new valve concepts and catheters for patients requiring valve procedures in both the mitral and aortic positions. Future research should also address appropriate valve sizing for transcatheter valve-in-valve implantation. One possible disadvantage of a staged approach is the adhesion that may develop around the left ventricular apex between procedures. In our case, no tenacious adhesions were present. In our opinion, in case of reintervention, the minimal approach to a transapical prosthesis may reduce the risk of intraoperative complications.

Conclusion

In conclusion, following accurate patient selection and evaluation by an experienced multidisciplinary team, the transcatheter approach to double-valve implantation in the aortic and mitral positions may represent a viable treatment option for those high-risk patients who would otherwise be inoperable.

Conflict of interest: none declared.