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.

     

Pregnancy and transcatheter aortic valve replacement in a severely stenotic Freestyle full aortic root stentless bioprosthesis

Symptomatic degenerative prosthetic aortic valve stenosis during pregnancy represents a significant risk to both mother and fetus, and until recently, surgical aortic valve replacement (SAVR) during pregnancy was often the only choice for women opting to continue pregnancy. However, symptomatic severe stenosis in a pregnant woman with a degenerated full aortic root Freestyle stentless bioprosthesis (FSB) and reimplanted coronary arteries presents additional complexities that require an alternative surgical approach. In this case report, we describe the first successful transcatheter aortic valve replacement (TAVR) in SAVR for a severely stenotic degenerative FSB in a pregnant woman and subsequent delivery of a healthy infant several months later. TAVR in SAVR of a severely stenotic aortic FSB should be considered as a surgical option in symptomatic pregnant women. Short‐term and long‐term implications for future pregnancy should be discussed by a multidisciplinary team and with the patient.     

Iatrogenic communications between aortic root and right ventricle/left atrium after transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has emerged as an alternative, less invasive treatment option for patients with severe symptomatic aortic stenosis, who are high‐risk for conventional surgical aortic valve replacement, due to co‐morbidities. In addition to a 30‐day 10% mortality risk there is a recognized range of complications, which commonly relate to vascular access trauma, paravalvular aortic regurgitation, and cerebrovascular events. In the following case reports, we discuss two previously unreported complications of TAVR: (i) an iatrogenic communication between the aortic root and the right ventricle and (ii) an iatrogenic communication between the aortic root and the left atrium. Informed written consent was obtained from both paztients. © 2013 Wiley Periodicals, Inc.     

Transcatheter aortic valve replacement and stroke: a comprehensive review

Transcatheter aortic valve implantation (TAVR) has emerged as an alternative, rapidly evolving treatment option for patients with severe aortic stenosis and high surgical risk. Stroke is a devastating complication being confined mainly in the periprocedural and 30-day period following TAVR, with a lower and relatively constant frequency thereafter. Early stroke is mainly due to debris embolization during the procedure, whereas later events are associated with patient specific factors. Despite the fact that the rate of clinical stroke has been constantly decreasing compared to initial TAVR experience, modern neuro-imaging with MRI suggests that new ischemic lesions post-TAVR are almost universal. The impact of the latter is largely unknown. However, they seem to correlate with a reduction in neurocognitive function. Because TAVR is set to expand its indication to lower surgical-risk patients, stroke prophylaxis during and after TAVR becomes of paramount importance. Based on clinical and pathophysiological evidence, three lines of research are actively employed towards this direction: improvement in valve and delivery system technology with an aim to reduce manipulations and contact with the calcified aortic arch and native valve, antithrombotic therapy, and embolic protection devices. Careful patient selection, design of the procedure, and tailored antithrombotic strategies respecting the bleeding risks of this fragile population constitute the main defense against stroke following TAVR.     

Meta‐analysis of complications in aortic valve replacement: Comparison of Medtronic‐Corevalve,Edwards‐Sapien and surgical aortic valve replacement in 8,536 patients

Background : We sought to establish the complication rates following transcatheter aortic valve replacement (TAVR) in the context of high risk and octogenarian surgical aortic valve replacement (SAVR) in the contemporary literature, and to critically analyze population characteristics and outcomes. Methods : TAVR studies were selected from nonoverlapping series and SAVR studies for comparison if they met similar entry criteria. Bayesian meta‐analytic methods were employed. Results : For the 5024 TAVR and 3512 SAVR patients included in the study, TAVR subjects had greater baseline renal impairment (P < 0.001), a higher incidence of prior myocardial infarction (P = 0.032) and respiratory disease (P = 0.005) and a higher logistic EuroSCORE (P = 0.039). There were no significant differences observed in complications studied in SAVR and TAVR: 30 day mortality (9% vs 8.5%, P = 0.31), 1 year mortality (18.4% vs 22.8%, P = 0.65), 30 day stroke (2.4% vs 2.6%, P = 0.72), new permanent pacemaker (5.9% vs 12.1%, P = 0.055) and dialysis inception (2.4% vs 4.1%, P = 0.70). We also compared demographics and outcomes between the two types of transcatheter valves. Apart from some variation in functional status, there were no significant differences at baseline with different TAVR designs. The only difference in complications was the need for pacemaker insertion, higher with the Medtronic‐Corevalve than with the Edwards‐Sapien design (24.5% vs 5.9% P < 0.0001). Conclusions : Complications for elderly and high risk aortic stenosis patients being treated by TAVR appear comparable to those selected for SAVR in the real‐world. © 2012 Wiley Periodicals, Inc.     

Periaortic hematoma after transcatheter aortic valve replacement: Description of a new complication

We report a case series of three patients with periaortic hematomas following transcatheter aortic valve replacement (TAVR). The TAVRs were performed by either trans‐apical or transfemoral approach. An intraprocedural transesophageal echocardiogram (TEE) was performed in all patients. Clinical features of all three cases included advanced age, female gender, and small body weight. In addition, the following characteristics were present in all cases: presence of bulky calcification of the noncoronary cusp (NCC) of the aortic valve, mismatch between the annulus and device diameter, and severe intraprocedural hypertension immediately following TAVR. These characteristics may be potential causative factors. Early recognition of this complication by intra‐procedural TEE was integral to the initiation of rapid and appropriate therapy, resulting in a favorable outcome. Herein, we present possible theories for the occurrence of this rare complication. © 2011 Wiley Periodicals, Inc.     

Carotid artery access for transcatheter aortic valve replacement

We report three patients who had successful transcatheter aortic valve replacement (TAVR) via carotid artery access. None were candidates for thoracotomy (including minimal access incisions) and had no other vascular access sites that would accommodate the transcatheter valve sheath. Antegrade carotid perfusion and retrograde insertion of the delivery sheath maintained cerebral blood flow without sequelae. Carotid access for TAVR is an option for unusual patients without other access. © 2012 Wiley Periodicals, Inc.     

Transcatheter aortic valve replacement using the new Evolut-Pro system: a prospective comparison with the Evolut-R device

BackgroundEvolut Pro (EVP) is a novel self-expandable aortic valve. This prosthesis consists of an external porcine pericardial wrap designed to reduce paravalvular leak (PVL), maintaining the benefits of its predecessor, the Evolut R (EVR). The aim was to compare the functional and clinical results in the short and medium term of the new EVP with the EVR system.MethodsConsecutive patients receiving either the EVR (n=50) or the EVP (n=33) from June 2015 to October 2018 were compared. Baseline characteristics, cardiovascular imaging, procedural outcomes, short and mid-term follow-up outcomes were prospectively collected and assessed.ResultsResidual mild PVL was common and comparable in the two groups (EVR 79% vs. EVP 70%; P=0.4). In the EVR group, the presence of PVL was directly related to prosthesis size, but this correlation was not observed in the EVP group. Conduction abnormalities were more prevalent with the EVP, but these did not translate into a higher need of permanent pacemaker implantation. Vascular and bleeding complications were infrequent in both groups. At mid-term clinical follow-up (median survival time: EVR 11±0.3 months, EVP 12±0.2 months), the 1-year rate of adverse events was similar (EVR: 24%, EVP: 33%; P=0.3).ConclusionsBoth protheses are effective for the treatment of severe aortic stenosis with excellent results at mid-term clinical follow up. The EVP remains associated with a significant rate of residual mild PVL that appears to be similar to that observed with EVR.     

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.