Transcatheter aortic valve implantation: current status and future perspectives

Frequency and impact of incidental findings on computed tomography during work-up for transcatheter aortic valve implantation: single centre experience and review of the literature

OBJECTIVE

To assess the frequency and impact of incidental findings (IF) on CT during work-up for transcatheter aortic valve intervention (TAVI).

METHODS

A consecutive cohort of patients referred for consideration of TAVI who underwent a CT scan between 2009 and 2018 were studied retrospectively. CT reports were reviewed for the presence of IFs and categorised based upon their clinical significance: (a) insignificant-findings that did not require specific treatment or follow-up; (b) intermediate-findings that did not impact on the decision-making process but required follow-up; (c) significant-findings that either required urgent investigation or meant that TAVI was clinically inappropriate.

RESULTS

A total of 652 patients were included, whose median age was 82 years. One or more insignificant IF was found in 95.6% of patients. Intermediate IFs were documented in 5.4%. 91 (14%) patients had at least one significant IF. These included possible malignancy in 67 (74%). The ultimate decision to offer aortic valve intervention was only changed by the presence of an IF in 3.5% of cases.

CONCLUSION

Clinically significant IFs are detected in more than 1 in 10 of patients undergoing CT as part of a TAVI work-up, although just over half of these patients still receive aortic valve intervention.

ADVANCES IN KNOWLEDGE

This study is the largest UK cohort, which, when combined with a review of existing literature, provides a clear picture of the frequency and clinical impact of IFs found at CT for TAVI assessment.

Early outcomes of transcatheter tricuspid valve-in-valve implantation: a case series

OBJECTIVES

In this study, we sought to evaluate early outcomes of transcatheter valve-in-valve implantation in patients with a degenerated bioprosthesis in the tricuspid position.

METHODS

We used a prospective study, which included patients with a degenerated bioprosthesis in the tricuspid position who were considered high-risk by our heart team and who underwent a valve-in-valve implantation. The procedures were performed via transjugular venous access and were done with the patient under general anaesthesia with transoesophageal echocardiographic and fluoroscopic guidance. Perioperative data were analysed, and the patients were followed prospectively.

RESULTS

Seven patients were included. The baseline diagnoses were 3 patients with Ebstein's anomaly, 1 patient with tetralogy of Fallot, 1 patient with neonatal endocarditis, 1 patient with ventricular septal defect with a double tricuspid lesion and 1 patient with rheumatic mitral and tricuspid valve who underwent a combined transapical mitral and transjugular tricuspid valve-in-valve implantation. The mean age was 33 ± 10.8 years and 57.1% of the patients were men. The mean number of previous thoracotomies was 3 ± 2 (range 1-5) procedures. The mean follow-up was 1.24 years. The implant was successful in all cases, and there was no need for conversion to open surgery. There were no deaths during the study period, and all patients are currently in the New York Heart Association functional class I/II. There was a statistically significant difference when the mean transvalvular gradients preimplantation and postimplantation were compared (P < 0.001).

CONCLUSIONS

Percutaneous tricuspid valve implantation should be considered a safe and effective therapy and stands as a viable, reliable alternative for the treatment of a degenerated bioprosthesis in high-surgical-risk/inoperable patients.

Permanent Pacemaker Implantation After Transcatheter Aortic Valve Replacement: A Cost Analysis

Background

Transcatheter aortic valve replacement (TAVR) can be complicated with a complete atrioventricular block requiring permanent pacemaker (PPM) implantation. The cost of index hospitalization for such patients is higher than usual. However, the magnitude of this increased cost is uncertain. We have looked at our five-year TAVR experience to analyze the detailed cost for PPM implantation in TAVR.

Methods

This study is a retrospective analysis of patients undergoing TAVR at our tertiary care center from December 2012 to April 2018. The initial sample size was 449. We excluded patients with prior PPM or an implantable cardioverter defibrillator (37). Patients who had their procedure aborted or required a cardiopulmonary bypass (16) and those with missing data variables (14) were excluded. The final sample size was 382. The cost for admission was calculated as the US dollars incurred by the hospital. Cohort costs were categorized as a direct cost, which is patient based, and an indirect cost, which represents overhead costs and is independent of patient volume. Patients were divided into two groups based on the placement of PPM after TAVR. Chi-square test, t-test, and logistic linear regression were used for the statistical analysis.

Results

Of 382 patients, 19 (4.9%) required PPM after TAVR. Baseline variables, including age, gender, and BMI, were not statistically significant. The PPM group had a significantly longer intensive care unit (ICU) stay (48.6 hours vs. 36.7 hours; p<0.001) and total stay in the hospital (4.2 days vs. 3.4 days; p=0.047). PPM implantation after TAVR increased cost on an average of $10,213 more than a typical TAVR admission (p=0.04). The direct cost was also significantly high for the PPM group ($7,087; p=0.02). On detailed analysis, almost all major cost categories showed a higher cost for pacemaker patients when compared with control.

Conclusions

PPM implantation adds a significant cost burden to TAVR admissions.

A case report: black oesophagus as a possible complication of transcatheter aortic valve implantation

Background

The increasing number of transcatheter aortic valve implantation (TAVI) in the last few years has unveiled a unique set of events and complications that need prompt recognition and management in order to improve patient outcomes, often involving a multidisciplinary team.

Case summary

We present a case of a 86-year-old woman with symptomatic severe aortic stenosis that underwent a TAVI and, in the post-procedure period, presented with acute abundant haematemesis, haemodynamic instability, and haemoglobin drop. The diagnosis of acute necrotizing oesophagitis (ANE) was made by upper gastrointestinal endoscopy.

Discussion

Acute necrotizing oesophagitis is a rare entity caused usually by an ischaemic insult in the presence of predisposing factors; it has a high rate of complications and mortality. To the best of our knowledge, this is the first clinical case report to describe the occurrence of ANE as a possible complication of TAVI and is also an example of the importance of the multidisciplinary approach of these complex patients, which extends even beyond the concept of Heart Team.

Transcatheter aortic valve implantation vs. surgical aortic valve replacement for treatment of symptomatic severe aortic stenosis: an updated meta-analysis

Aims 

Owing to new evidence from randomized controlled trials (RCTs) in low-risk patients with severe aortic stenosis, we compared the collective safety and efficacy of transcatheter aortic valve implantation (TAVI) vs. surgical aortic valve replacement (SAVR) across the entire spectrum of surgical risk patients.

Methods and results 

The meta-analysis is registered with PROSPERO (CRD42016037273). We identified RCTs comparing TAVI with SAVR in patients with severe aortic stenosis reporting at different follow-up periods. We extracted trial, patient, intervention, and outcome characteristics following predefined criteria. The primary outcome was all-cause mortality up to 2 years for the main analysis. Seven trials that randomly assigned 8020 participants to TAVI (4014 patients) and SAVR (4006 patients) were included. The combined mean STS score in the TAVI arm was 9.4%, 5.1%, and 2.0% for high-, intermediate-, and low surgical risk trials, respectively. Transcatheter aortic valve implantation was associated with a significant reduction of all-cause mortality compared to SAVR {hazard ratio [HR] 0.88 [95% confidence interval (CI) 0.78–0.99], P = 0.030}; an effect that was consistent across the entire spectrum of surgical risk (P-for-interaction = 0.410) and irrespective of type of transcatheter heart valve (THV) system (P-for-interaction = 0.674). Transcatheter aortic valve implantation resulted in lower risk of strokes [HR 0.81 (95% CI 0.68–0.98), P = 0.028]. Surgical aortic valve replacement was associated with a lower risk of major vascular complications [HR 1.99 (95% CI 1.34–2.93), P = 0.001] and permanent pacemaker implantations [HR 2.27 (95% CI 1.47–3.64), P < 0.001] compared to TAVI.

Conclusion 

Compared with SAVR, TAVI is associated with reduction in all-cause mortality and stroke up to 2 years irrespective of baseline surgical risk and type of THV system.

Infective Endocarditis in the Elderly: Diagnostic and Treatment Options

Infective endocarditis (IE) is an uncommon, life-threatening systemic disorder with significant morbidity and persistently high mortality. The age of the peak incidence of IE has shifted from 45 years in the 1950s to 70 years at the present time, and elderly people have a five-fold higher risk of IE than the general adult population. Elderly IE patients demonstrate a higher prevalence of coagulase-negative staphylococci, enterococci and Streptococcus bovis, and lower rates of infection by viridans group streptococci. Methicillin resistance is more prevalent in elderly patients as a consequence of increased nosocomial acquisition. The elderly are a vulnerable group in whom diagnosis is often difficult on account of non-specific presenting features and where higher prevalence of comorbidities contributes to adverse outcomes. Treatment of older patients with IE presents specific challenges associated with prolonged antibiotic therapy, and access to surgery may be denied on account of advanced age and attendant comorbidities. This practical review covers all aspects of elderly IE, including clinical and microbiological diagnosis and appropriate diagnostic procedures, initial antibiotic selection, antibiotic prophylaxis, considerations about antibiotic therapy and surgery.

Comparison of transcatheter aortic valve implantation with other approaches to treat aortic valve stenosis: a systematic review and meta-analysis

BACKGROUND

Transcatheter aortic valve replacement (TAVI) is an alternative treatment for patients with symptomatic severe aortic stenosis ineligible for surgical aortic valve replacement (SAVR) or at increased perioperative risk. Due to continually emerging evidence, we performed a systematic review and meta-analysis comparing benefits and harms of TAVI, SAVR, medical therapy, and balloon aortic valvuloplasty.

METHODS

We searched MEDLINE, Embase, and Cochrane CENTRAL from 2002 to June 6, 2017. We dually screened abstracts and full-text articles for randomized controlled trials (RCTs) and propensity score-matched observational studies. Two investigators independently rated the risk of bias of included studies and determined the certainty of evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation). If data permitted, we performed meta-analyses using random- and fixed-effects models.

RESULTS

Out of 7755 citations, we included six RCTs (5862 patients) and 13 observational studies (6376 patients). In meta-analyses, patients treated with SAVR or TAVI had similar risks for mortality at 30 days (relative risk [RR] 1.05; 95% confidence interval [CI] 0.82 to 1.33) and 1 year (RR 1.02; 95% CI 0.93 to 1.13). TAVI had significantly lower risks for major bleeding but increased risks for major vascular complications, moderate or severe paravalvular aortic regurgitation, and new pacemaker implantation compared to SAVR. Comparing TAVI to medical therapy, mortality did not differ at 30 days but was significantly reduced at 1 year (RR 0.51; 95% CI 0.34 to 0.77).

CONCLUSIONS

Given similar mortality risks but different patterns of adverse events, the choice between TAVI and SAVR remains an individual one.

Aortic Stenosis and Transcatheter Aortic Valve Implantation: Current Status and Future Directions in Korea

Transcatheter aortic valve implantation (TAVI) has been accepted as one of primary options for treatment of symptomatic severe aortic stenosis. Although TAVI has been predominantly used for patients at high risk or with old age who were not considered optimal candidates for surgical aortic valve replacement (SAVR), its indication is now expanding toward low risk profile and younger age. Many clinical trials are now ongoing to test the possibility of TAVI for use in patients even with uncharted indications who are not eligible for SAVR in current guidelines but may benefit from valve replacement. Current issues including periprocedural safety, long-term adverse events, hemodynamics and durability associated with TAVI should be also solved for expanding use of TAVI. The review presents current status and future directions of TAVI and discusses perspectives in Korea.

Maturation from CoreValve® to Evolut Pro®: a clinical overview

The only curative treatment of aortic stenosis is through surgical or transcatheter aortic valve replacement. Transcatheter aortic valve implantation has evolved from its first in human experience in 2002 and matured to the treatment of first choice of symptomatic severe aortic stenosis in elderly patients with an elevated operative risk. The self-expanding CoreValve^® bioprosthesis has been on the forefront of this growing transcatheter aortic valve implantation experience. Over the last decade, various device iterations resulted in the current Evolut PRO^® self-expanding valve platform with reduced profile, repositioning/retrievable features and porcine pericardial wrap. Herein we provide a critical appraisal of the consecutive device iterations and highlight the clinical foundation for the use of the self-expanding CoreValve^® /Evolut platforms in current clinical practice.

Health-related quality of life following transcatheter aortic valve implantation using transaortic, transfemoral approaches and surgical aortic valve replacement-a single-center study

Objective

To evaluate short- and long-term changes in quality of life (QoL) in patients undergoing transcatheter aortic valve implantation (TAVI) and to assess differences in patient QoL when using the TAVI transaortic (TAVI TAo) approach compared with the transfemoral approach (TAVI TF) and surgical aortic valve replacement (SAVR).

Methods

Ninety-seven patients were assessed. Thirty-two patients underwent TAVI TAo, 31 underwent TAVI TF and 34 patients underwent SAVR. QoL was assessed using the EQ-5D-3L questionnaire at baseline, after one month and one year.

Results

Mean patient age was 80 years (range, 61–92 years) and the mean logistic EuroSCORE was 12.45% (range, 1.39%–78.98%). Declared health state at baseline was significantly lower in TAVI TF (P < 0.001) and after one month there were no differences between the three groups (P = 0.99). After one year, SAVR patient results of the EQ-5D-3L index value were lower in comparison to both TAVI patient groups (P < 0.05). The analysis also showed significant differences between the results of EQ-5D-3L index value over the one month and one year follow-up (TAVI TAo, P < 0.001; TAVI TF, P < 0.05; SAVR, P < 0.05). In all groups, the values significantly increased after one-month and one-year of follow-up in comparison to baseline value. Significant differences were also demonstrated between Visual Analogue Scale values (VAS).

Conclusions

A significant improvement in QoL was observed in all three patient groups. Regardless of the TAVI approach, EQ-5D-3L and VAS values were significantly increased after one-month and one-year follow up; the SAVR patients however, reported lower health status when compared to the TAVI patients.

[Diagnosis and treatment of aortic valve stenosis]

Aortic valve stenosis (AS) is the most frequently observed valvular heart disease. Once it is symptomatic the mortality rapidly increases. The diagnostic gold standard is transthoracic echocardiography. By measuring the maximum transvalvular velocity, mean transaortic pressure gradient and aortic valve opening area, classification of the type of stenosis can be defined. A differentiation is made between high-gradient AS, low-flow low gradient AS with reduced ventricular ejection fraction (<50%) and the paradoxical low-flow low-gradient AS with preserved ventricular function (≥50%). In some cases, additional diagnostic tools are necessary using dobutamine stress echocardiography, transesophageal echocardiography and cardiac computed tomography. The treatment follows an individualized approach. In cases of indications for valve replacement the multidisciplinary heart team takes into account the patient's age and individual risk for deciding whether an open surgical approach or transcatheter aortic valve implantation is indicated.

Principles of TAVR valve design, modelling, and testing

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has emerged as an effective minimally-invasive alternative to surgical valve replacement in medium- to high-risk, elderly patients with calcific aortic valve disease and severe aortic stenosis. The rapid growth of the TAVR devices market has led to a high variety of designs, each aiming to address persistent complications associated with TAVR valves that may hamper the anticipated expansion of TAVR utility.

AREAS COVERED

Here we outline the challenges and the technical demands that TAVR devices need to address for achieving the desired expansion, and review design aspects of selected, latest generation, TAVR valves of both clinically-used and investigational devices. We further review in detail some of the up-to-date modeling and testing approaches for TAVR, both computationally and experimentally, and additionally discuss those as complementary approaches to the ISO 5840-3 standard. A comprehensive survey of the prior and up-to-date literature was conducted to cover the most pertaining issues and challenges that TAVR technology faces.

EXPERT COMMENTARY

The expansion of TAVR over SAVR and to new indications seems more promising than ever. With new challenges to come, new TAV design approaches, and materials used, are expected to emerge, and novel testing/modeling methods to be developed.

Aortic Valve Replacement for Aortic Stenosis in Elderly Patients (75 Years or Older)

Background

This study evaluated the early and long-term outcomes of surgical aortic valve replacement (AVR) in elderly patients in the era of transcatheter aortic valve implantation.

Methods

Between 2001 and 2018, 94 patients aged ≥75 years underwent isolated AVR with stented bioprosthetic valves for aortic valve stenosis (AS). The main etiologies of AS were degenerative (n=63) and bicuspid (n=21). The median follow-up duration was 40.7 months (range, 0.6-174 months).

Results

Operative mortality occurred in 2 patients (2.1%) and paravalvular leak occurred in 1 patient. No patients required permanent pacemaker insertion after surgery. Late death occurred in 11 patients. The overall survival rates at 5 and 10 years were 87.2% and 65.1%, respectively. The rates of freedom from valve-related events at 5 and 10 years were 94.5% and 88.6%, respectively. The Society of Thoracic Surgeons (STS) score (p=0.013) and chronic kidney disease (p=0.030) were significant factors affecting long-term survival. The minimal p-value approach demonstrated that an STS score of 3.5% was the most suitable cut-off value for predicting long-term survival.

Conclusion

Surgical AVR for elderly AS patients may be feasible in terms of early mortality and postoperative complications, particularly paravalvular leak and permanent pacemaker insertion. The STS score and chronic kidney disease were associated with long-term outcomes after AVR in the elderly.

Optimal structure of TAVI heart centres in 2018

Transcatheter aortic valve implantation (TAVI) is evolving, with a dramatic increase in the number of procedures all over the world and a progressive shift to lower-risk patients. Valvular heart centres are accordingly adapting to the new needs and targets of the treated population. The purpose of this review is to provide an overview of the evolution of heart valve centres following changes in TAVI over time. In particular, we will discuss: 1) new challenges for the Heart Team in patient profiling and procedural tailoring; 2) the continued need for TAVI to be performed in high-volume centres with cardiac surgery on site; and 3) the importance of integrated imaging tools in modern heart valve centres.

Appraisal of key trials in aortic and mitral fields

Aortic stenosis and mitral regurgitation are increasingly treated by percutaneous interventions including transcatheter aortic valve implantation (TAVI) and several mitral valve repair techniques, changing the landscape of valvular therapies in which surgery was predominant. Several randomised studies on TAVI have led to the use of this procedure in patients at intermediate or higher operative risk and have set strong foundations for future trials aiming to expand indications or to overcome several residual issues with TAVI. On the other hand, randomised evidence for percutaneous mitral valve repair (PMVR) techniques is still limited, supporting restricted indications to patients with high surgical risk when medical therapy fails. However, in the mitral field, several ongoing trials comparing PMVR with medical therapy or surgery will help to define optimal mitral regurgitation management in this era of evolving catheter-based treatment options. The present review will summarise randomised trials comparing TAVI or PMVR with medical therapy or surgery across the risk spectrum which have set the basis for guideline recommendations and for clinical use of transcatheter interventions. Characteristics, results, implications, unresolved issues and cost-effectiveness analysis of those trials, grouped according to the surgical risk of enrolled patients, will be appraised.