Transcatheter aortic valve replacement: The year in review 2016

Transcatheter aortic valve replacement (TAVR) continued to make major strides in 2016, simultaneously expanding its application to lower risk patients as well as more technically challenging subsets of patients with aortic stenosis (AS). The two major accomplishments this year were the establishment of TAVR as the preferred treatment strategy over surgical aortic valve replacement (SAVR) in intermediate risk patients, and initial signals that TAVR and SAVR may be clinically equivalent in low‐risk populations. Meanwhile, there is continued expansion of TAVR to challenging clinical subsets (bicuspid aortic valve [BAV], patients with concomitant advanced coronary artery disease [CAD], and failed surgical bioprostheses), and encouraging initial experiences with newer transcatheter heart valve systems. This paper summarizes the major research studies published on TAVR in 2016.

     

Transcatheter aortic valve replacement in elderly patients

Aortic stenosis is the most common native valve disease, affecting up to 5% of the elderly population. Surgical aortic valve replacement reduces symptoms and improves survival, and is the definitive therapy in patients with symptomatic severe aortic stenosis. However, despite the good results of classic surgery, risk is markedly increased in elderly patients with co-morbidities. Transcatheter aortic valve replacement (TAVR) allows implantation of a prosthetic heart valve within the diseased native aortic valve without the need for open heart surgery and cardiopulmonary bypass, offering a new therapeutic option to elderly patients considered at high surgical risk or with contraindications to surgery. To date, several multicenter registries and a randomized trial have confirmed the safety and efficacy of TAVR in those patients. In this chapter, we review the background and clinical applications of TAVR in elderly patients.     

Reversible thrombotic aortic valve restenosis after valve‐in‐valve transcatheter aortic valve replacement

Thrombotic aortic valve restenosis following transcatheter aortic valve replacement (TAVR) has not been extensively reported and the rates of TAVR valve thrombosis are not known. We present three cases of valve‐in‐valve (VIV) restenosis following TAVR with the balloon expandable transcatheter heart valves, presumably due to valve thrombosis that improved with anticoagulation. © 2016 Wiley Periodicals, Inc.     

Transcatheter aortic valve in valve implantation with bioprosthetic valve fracture

Valve‐in‐valve transcatheter aortic valve replacement (VIV TAVR) has emerged as a preferable option for high surgical risk patients requiring redo aortic valve replacement. However, VIV TAVR may restrict flow, especially in small native aortic valves. To remedy this, bioprosthetic valve fracture has been utilized to increase the effective orifice area and improve hemodynamics. We present three cases in which bioprosthetic valve fracture was used to increase hemodynamic flow in VIV TAVR procedures.     

Urgent transcatheter aortic valve replacement for severe acute aortic regurgitation following open mitral valve surgery

Transcatheter aortic valve replacement (TAVR) is not currently approved for pure native valve aortic incompetence, and is typically performed on a compassionate basis in selected patients who are at high risk for conventional surgery. We describe the first use of TAVR to treat iatrogenic severe acute pure aortic incompetence following mitral valve surgery. A 71‐year‐old gentleman developed life‐threatening acute aortic regurgitation (AR) within hours of a very challenging fifth open heart mitral valve replacement. Careful inspection of echocardiographic and computed tomographic imaging identified the cause as a disrupted left coronary cusp at the commissure caused by the surgical mitral annular reconstruction. Medical management with afterload reduction failed with recurrent pulmonary edema, and a sixth open heart surgery was deemed prohibitively high risk. The lack of aortic annular calcium onto which anchors a transcatheter valve was a concern for TAVR. However, we postulated that the struts of the mitral valve bioprosthesis would offer some support to the TAVR valve. We opted for a self‐expanding system because of concerns about potential unfavorable interaction between the balloon onto which balloon‐expandable bioprosthesis is mounted and the struts of the mitral bioprosthesis, and because the Evolut R system has additional anchoring points at the crown which might enhance transcatheter valve stability in the non‐calcified annulus, compared with the Edwards Sapien system. Transfemoral TAVR, performed with a Medtronic Evolut R 34 mm system under general anesthesia and using moderately rapid ventricular pacing, was successful with minimal residual AR. On follow‐up 1 month later the patient was asymptomatic, and the aortic and mitral bioprostheses were functioning normally on echocardiogram.     

Transcatheter versus surgical aortic valve replacement in severe, symptomatic aortic stenosis

Aortic stenosis (AS) is the most common type of valvular heart disease in the elderly. Surgical aortic valve replacement (SAVR) has been the standard practice for treating severe, symptomatic AS, but recently new treatment options have emerged. Transcatheter aortic valve replacement (TAVR) is now an established treatment option in patients at high surgical risk. In this review, we focus on recent developments and compare the two treatment methods in specific populations in terms of efficacy and safety (e.g., in patients with history of prior thoracic surgery, type of anesthesia employed, access site used or need for permanent pacing). The impact of comorbidities (pulmonary hypertension, arterial hypertension and obesity paradox), the cost-effectiveness of TAVR vs. SAVR and advances in transcatheter valve technology as well as issues that merit further investigation are further discussed. Moreover, outcomes and complications of TAVR in patients of different risk category (extremely high, high, intermediate and low risk) are analyzed. We strongly believe that during the following years, TAVR may evolve as the treatment of choice in a broader group of patients with symptomatic AS and beyond those with intermediate and high-risk features.     

Long-term outlook for transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) revolutionized the treatment of severe symptomatic aortic stenosis (AS). TAVR is increasingly offered for lower-risk patients. The role and place of TAVR in the future treatment of AS is not clear yet. In this review, we discuss the long-term outlook for TAVR, its challenges and its relationship to conventional surgical aortic valve replacement.     

The impact of mitral stenosis on outcomes of aortic valve stenosis patient undergoing surgical aortic valve replacement or transcatheter aortic valve replacement

Background

The concomitant presence of mitral stenosis (MS) in the setting of symptomatic aortic stenosis represent a clinical challenge. Little is known regarding the outcome of mitral stenosis (MS) patients undergoing transcatheter aortic valve replacement (TAVR) or surgical aortic valve replacement (SAVR). Therefore, we sought to study the outcome of MS patients undergoing aortic valve replacement (AVR).

Method

Using weighted data from the National Inpatient Sample (NIS) database between 2011 and 2014, we identified patients who were diagnosed with MS. Patients who had undergone TAVR as a primary procedure were identified and compared to patients who had SAVR. Univariate and multivariate logistic regression analysis were performed for the outcomes of in‐hospital mortality, length of stay (LOS), blood transfusion, postprocedural hemorrhage, vascular, cardiac and respiratory complications, permanent pacemaker placement (PPM), postprocedural stroke, acute kidney injury (AKI), and discharge to an outside facility.

Results

A total of 4524 patients were diagnosed with MS, of which 552 (12.2%) had TAVR and 3972 (87.8%) had SAVR. TAVR patients were older (79.9 vs 70.0) with more females (67.4% vs 60.0%) and African American patients (7.7% vs 7.1%) (P < 0.001). In addition, the TAVR group had more comorbidities compared to SAVR in term of coronary artery disease (CAD), congestive heart failure (CHF), chronic lung disease, hypertension (HTN), chronic kidney disease (CKD), and peripheral vascular disease (PVD) (P < 0.001 for all). Using Multivariate logistic regression, and after adjusting for potential risk factors, TAVR patients had lower in‐hospital mortality (7.9% vs 8.1% adjusted Odds Ratio [aOR], 0.615; 95% confidence interval [CI], 0.392–0.964, P = 0.034), shorter LOS. Also, TAVR patients had lower rates of cardiac and respiratory complications, PPM, AKI, and discharge to an outside facility compared with the SAVR group.

Conclusion

In patients with severe aortic stenosis and concomitant mitral stenosis, TAVR is a safe and attractive option for patients undergoing AVR with less complications compared with SAVR.

     

经导管主动脉瓣置换的介入瓣膜的现状及展望

经导管主动脉瓣置换术（TAVR）经过最近几年快速发展已经取得巨大进步。迄今为止全球接受TAVR的患者数已近3万例,已成为无法耐受传统手术患者的标准备选治疗措施。从目前已临床应用的介入瓣膜到正在实验研究的新型介入瓣膜可以看出,未来介入瓣膜的发展目标是尺寸更小、长期有效、安全性高、并发症少、操作简单及定位精准。随着TAVR的推广,新型介入瓣的研发,操作者经验的积累,以及长期随访的开展,将给TAVR提供更科学的病例选择标准,减少介入手术的相关并发症,提高更安全有效的治疗效果。未来此项技术还会逐渐扩大适用人群的范围,成为代替传统的主动脉瓣置换术举足轻重的治疗措施。     

Current status of transcatheter aortic valve replacement

Surgical aortic valve replacement (SAVR) has long been the mainstay of therapy for severe aortic stenosis. However, transcatheter aortic valve replacement (TAVR) is now generally accepted as the new standard of care for patients with symptomatic aortic stenosis who are not candidates for open surgery. Arguably TAVR may also be a preferred alternative to SAVR in carefully selected high-risk, but still operable, patients in whom morbidity and mortality may be reduced. Although TAVR outcomes continue to improve, concerns remain with respect to vascular injury, stroke, paravalvular regurgitation, and valve durability. However, it seems likely that with ongoing refinement of transcatheter valve systems, techniques, and patient selection TAVR is becoming an increasingly appealing option for a much broader range of patients. Randomized trials and ongoing surveillance will play an important role as we enter a new era of rigorous clinical evaluation for minimally invasive therapies for structural heart disease.     

High pacing rates for management of aortic insufficiency after balloon aortic valvuloplasty or transcatheter aortic valve replacement

Aortic insufficiency (AI) after transcatheter aortic valve replacement (TAVR) is difficult to manage when associated with congestive heart failure. AI after balloon aortic valvuloplasty (BAV) may be catastrophic, especially in patients who are not candidates for TAVR. We describe the use of urgent temporary pacing, followed by permanent pacing, to increase the heart rate to diminish diastolic filling time for the short term management of AI after BAV or TAVR. The strategy is particularly useful in patients who already have permanent pacemakers, which are common in this population. © 2013 Wiley Periodicals, Inc.     

Transcatheter aortic valve replacement in unicuspid aortic valve stenosis

Unicuspid aortic valve (UAV) offers unique challenges to transcatheter aortic valve replacement (TAVR), due to asymmetric expansion and apposition of the prosthesis during implantation. Although TAVR in bicuspid is now a well described experience, TAVR in unicuspid valve has not yet been described. A challenging case is described with TAVR in UAV using a Edwards Sapiens prosthesis via transapical approach. © 2016 Wiley Periodicals, Inc.     

Successful minimal approach transcatheter aortic valve replacement in an allograft heart recipient 19 years post transplantation for severe aortic stenosis: A case report

BACKGROUND Aortic stenosis is one of the rare valvular complications in a transplanted heart.Over the past 8 years, transcatheter approach for aortic valve replacement(TAVR) has been slowly evolving to be the preferred approach in these patient population when compared to the surgical approach. We report a second case in the United States with successful transfemoral minimal approach with minimal sedation for TAVR in a heart transplant recipient 19 years post transplantation for severe symptomatic calcified aortic stenosis.CASE SUMMARY We present a case of 73-year-old male who has undergone successful minimal approach transcatheter aortic valve replacement in an allograft heart. Patient had received orthotopic heart transplantation 19 years ago for non-ischemic cardiomyopathy. Follow up transthoracic echocardiograms as per routine protocol did not show any aortic valve disease until 15 years post transplantation.Aortic valve was noted to be mildly sclerotic at that time and gradually progressed to severe symptomatic aortic stenosis over the next 4 years. Patient had complaints of worsening shortness of breath that limited his functional capacity. Overall his post heart transplantation period has been mostly uneventful except for allograft non occlusive vasculopathy and aortic stenosis.His Society of Thoracic Surgery risk score was 12.205% and he was considered to be a high-risk surgical candidate by surgeon. Decision was made to undergo transcatheter aortic valve replacement.CONCLUSION With the improved survival of these patients, we think it is time to look intopathophysiology of valvular disease in transplant heart recipients. Some other unanswered questions include, underlying donor and recipient risk factors for valvular diseases in heart transplant recipients.     

Bioprosthetic aortic valve leaflet disruption with high energy electrocautery to prevent coronary artery obstruction during valve‐in‐valve transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) is well‐established for the treatment of bioprosthetic aortic valve stenosis (AS) in high surgical risk patients. Coronary artery obstruction from displacement of the bioprosthetic valve leaflets during valve‐in‐valve (VIV) TAVR is a rare, but potentially fatal, complication. Recently, the bioprosthetic aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) procedure was developed as a method for disrupting bioprosthetic leaflets in patients undergoing VIV TAVR at high risk for coronary obstruction. This case describes a successful VIV TAVR utilizing a simplified concept of the BASILICA technique in a patient where the full procedure could not be completed.     

Sheathless transcatheter aortic valve implantation via the direct aortic approach

Transcatheter aortic valve replacement (TAVR) has become an accepted alternate treatment modality to surgical aortic valve replacement in high surgical risk patients. There remains, however, a subset of patients in whom safe delivery of a TAVR device cannot be achieved by the femoral or subclavian routes. In such cases the direct aortic or transapical routes can be used though this still requires suitable anatomy. We present the first reported case of a direct aortic TAVR using a sheathless technique in order to provide sufficient distance to safely deliver the prosthesis. © 2013 Wiley Periodicals, Inc.     

Simultaneous thoracic aortic endovascular graft and transfemoral transcatheter aortic valve replacement in a patient with a descending aortic thrombus

Severe descending thoracic and abdominal aortic pathology can deter consideration of transfemoral (TF) access for transcatheter aortic valve replacement (TAVR) in adults with severe symptomatic aortic stenosis (AS) and may lead to utilization of alternative access sites. We report a case of an 88-year-old frail woman with severe symptomatic AS referred for TAVR with demonstration of a large thrombus in the descending thoracic aorta immediately distal to the left subclavian artery. Given concerns of thrombus embolization with femoral advancement of the transcatheter valve, coverage with a thoracic aortic endograft was planned immediately prior to the TAVR.     

Vascular complications post-transcatheter aortic valve procedures

Transcatheter aortic valve replacement (TAVR) has rapidly emerged as the standard of care for severe symptomatic aortic stenosis in patients whose comorbidities put them at prohibitive risk for surgical aortic valve replacement (SAVR). Several trials have demonstrated superior outcomes with TAVR compared to medical management alone. TAVR has also shown favorable outcomes in patients at high risk for SAVR. TAVR can be associated with significant vascular complications, which adversely impact outcomes, and operators should be cognizant of their early recognition and appropriate management. In this article, we review the major vascular complications associated with TAVR, along with optimal prevention and management strategies.     

Transcatheter aortic valve replacement for native aortic valve regurgitation as a bridge to liver transplantation

Coexistence of end‐stage liver disease (ESLD) and severe valvular heart disease conveyed substantial risk for patients, oftentimes leading to exclusion from liver transplantation candidacy due to inability to safely offer cardiac surgery prior to transplantation. Several approaches have been described, including performing transplantation and valve surgery concurrently, or in sequence. Both options, however, have associated complications: catastrophic repercussion of peri‐operative coagulopathy and organ dysfunction post‐transplantation, respectively. The introduction of transcatheter procedures offered a safer alternative for high‐risk patients; however, its recognized indications remained limited. A novel approach to this surgical dilemma by performing transcatheter aortic valve replacement (TAVR) for severe native aortic valve regurgitation in a patient on the liver transplant list has been presented. The procedure proved to be an effective management for the aortic valve insufficiency, improving our patient's hemodynamics in preparation for the subsequent orthotopic liver transplantation (OLT). © 2015 Wiley Periodicals, Inc.     

Procedural and clinical outcomes of the valve‐in‐valve technique for severe aortic insufficiency after balloon‐expandable transcatheter aortic valve replacement

Objective : To describe the clinical and procedural outcomes of patients treated with the valve‐in‐valve technique for severe aortic insufficiency (AI) after balloon‐expandable transcatheter aortic valve replacement (TAVR). Background : Severe AI immediately after valve implantation is a notable complication of TAVR. It can be treated with a valve‐in‐valve technique which involves deploying a second valve within the first one to crush the leaflets of the first implant leaving a new functional valve. Methods : We analyzed data on 142 consecutive patients at our institution undergoing TAVR with the Sapien valve between November of 2007 and April of 2011. Etiologies of acute AI, procedural and intermediate term clinical outcomes were reported for those in whom a valve‐in‐valve procedure was necessary. Post‐hoc analysis of these cases with C‐THV imaging (Paieon Medical Ltd.) was performed to elucidate the mechanism for successful AI treatment. Results : A total of 5 of 142 (3.5%) patients were treated with the valve‐in‐valve technique. Etiologies of the aortic valve insufficiency included bioprosthesis malposition (n = 3), valve dysfunction (n = 1), and valve undersizing (n = 1). With placement of the second valve, the first valve dimensions increased to approach the nominal valve size while the second valve size remained less than nominal. Conclusions : The valve‐in‐valve technique is an appropriate bailout measure for patients with acute valvular AI after balloon‐expandable TAVR. © 2012 Wiley Periodicals Inc.     

Device closure of paravalvular defects following transcatheter aortic valve replacement with the Edwards Sapien valve

Paravalvular aortic insufficiency (AI) is observed in the majority of patients undergoing transcatheter aortic valve replacement (TAVR). While paravalvular AI is most commonly modest following TAVR, moderate or severe AI was seen in 10.5% and 6.8% of the PARTNER inoperable and high‐risk cohorts at 1 year and has been reportedly associated with dyspnea and diminished survival. We report two cases of transcatheter heart valve (THV) associated paravalvular defects closed using catheter delivered devices. Both patients derived hemodynamic and symptomatic improvement from device closure. Additional research is warranted to define the adverse consequences of THV associated AI, indications for treatment, and risks associated with device closure of these defects. © 2012 Wiley Periodicals, Inc.