Reoperative surgery for degenerated aortic bioprostheses: predictors for emergency surgery and reoperative mortality

Recent Outcomes of Surgical Redo Aortic Valve Replacement in Prosthetic Valve Failure

BACKGROUND

 As redo surgical aortic valve replacement (AVR) is relatively high risk, valve-in-valve transcatheter AVR has emerged as an alternative for failed prostheses. However, the majority of studies are outdated. This study assessed the current clinical outcomes of redo AVR.

METHODS AND RESULTS

 This study enrolled 324 patients who underwent redo AVR due to prosthetic valve failure from 2010 to 2021 in four tertiary centers. The primary outcome was operative mortality. The secondary outcomes were overall survival, cardiac death, and aortic valve-related events. Logistic regression analysis, clustered Cox proportional hazards models, and competing risk analysis were used to evaluate the independent risk factors. Redo AVR was performed in 242 patients without endocarditis and 82 patients with endocarditis. Overall operative mortality was 4.6% (15 deaths). Excluding patients with endocarditis, the operative mortality of redo AVR decreased to 2.5%. Multivariate analyses demonstrated that endocarditis (hazard ratio [HR]: 3.990, p = 0.014), longer cardiopulmonary bypass time (HR: 1.006, p = 0.037), and lower left ventricular ejection fraction (LVEF) (HR: 0.956, p = 0.034) were risk factors of operative mortality. Endocarditis and lower LVEF were independent predictors of overall survival.

CONCLUSION

 The relatively high risk of redo AVR was due to reoperation for prosthetic valve endocarditis. The outcomes of redo AVR for nonendocarditis are excellent. Our findings suggest that patients without endocarditis, especially with acceptable LVEF, can be treated safely with redo AVR.

Management Challenges in Patients Younger Than 65 Years With Severe Aortic Valve Disease

Importance

The management of aortic valve disease, including aortic stenosis and aortic regurgitation (AR), in younger adult patients (age <65 years) is complex, and the optimal strategy is often unclear, contingent on multiple anatomic and holistic factors.

Observations

Traditional surgical approaches carry significant considerations, including compulsory lifelong anticoagulation for patients who receive a mechanical aortic valve replacement (AVR) and the risk of structural valvular deterioration and need for subsequent valve intervention in those who receive a bioprosthetic AVR. These factors are magnified in young adults who are considering pregnancy, for whom issues of anticoagulation and valve longevity are heightened. The Ross procedure has emerged as a promising alternative; however, its adoption is limited to highly specialized centers. Valve repair is an option for selected patients with AR. These treatment options offer varying degrees of durability and are associated with different risks and complications, especially for younger adult patients. Patient-centered care from a multidisciplinary valve team allows for discussion of the optimal timing of intervention and the advantages and disadvantages of the various treatment options.

Conclusions and Relevance

The management of severe aortic valve disease in adults younger than 65 years is complex, and there are numerous considerations with each management decision. While mechanical AVR and bioprosthetic AVR have historically been the standards of care, other options are emerging for selected patients but are not yet generalizable beyond specialized surgical centers. A detailed discussion by members of the multidisciplinary heart team and the patient is an integral part of the shared decision-making process.

Valve-in-valve transcatheter aortic valve replacement versus redo aortic valve replacement: which procedure for which patient?

INTRODUCTION

Bioprosthetic aortic valves are increasingly being utilized in a younger population due to improved durability and possibility for future valve-in-valve replacement. This has resulted in a larger population of patients with bioprosthetic aortic valve degeneration requiring re-intervention. Despite no head-to-head comparisons between redo surgical aortic valve replacement (SAVR) and valve-in-valve transcatheter aortic valve replacement (ViV TAVR), observational studies suggest a comparable long-term risk between which led to the incorporation of ViV TAVR to current guidelines.

AREAS COVERED

This article summarizes the comparative performance of redo SAVR versus ViV TAVR in patients with bioprosthetic valve dysfunction and provides a guide to better understand which procedure is best for which patient.

EXPERT OPINION

With the rising use of TAVR, we will be confronted with more bioprosthetic aortic valve degeneration requiring re-intervention. Based on the available evidence and expert consensus, we propose that patients with bioprosthetic aortic valve degeneration be treated with ViV TAVR if they have a history of radiation heart disease, prohibitive surgical risk, and multiple sternotomies; while patients with small prostheses, history of infective endocarditis, those at high risk for coronary obstruction, and those with need for other cardiac surgery will be managed with redo SAVR.

Looking Back to Look Forward: What to Expect in a Redo Surgery for a Bioprosthesis Replacement

Redo surgeries are becoming more common because of an increased rate of bioprosthesis implantation. We performed a retrospective study on patients who underwent redo replacement of an aortic and/or mitral bioprosthesis between 2005 and 2018 to evaluate intra-hospital mortality and morbidity. Univariate analysis was performed on the propensity score variables to determine predictors of mortality. A total of 180 patients were enrolled in the study: Group A (replacement of aortic bioprosthesis) with 136 patients (75.56%) and group B (replacement of mitral bioprosthesis ± aortic bioprosthesis) with 44 patients (24.44%). NYHA class ≥ 3 and female sex were significantly more common in group B. Cardiopulmonary-bypass time and aortic cross-clamping time in group A and group B were, respectively, 154.95 ± 74.35 and 190.25 ± 77.44 (p = 0.0005) and 115.99 ± 53.54 and 144.91 ± 52.53 (p = 0.0004). Overall mortality was 8.89%. After propensity score adjustment, Group B was confirmed to have an increased risk of death (OR 3.32 CI 95% 1.02−10.88 p < 0.0001), gastrointestinal complications (OR 7.784 CI 95% 1.005−60.282 p < 0.0002) and pulmonary complications (OR 2.381 CI 95% 1.038−5.46 p < 0.0001). At the univariate analysis, endocarditis, cardiopulmonary-bypass and aortic cross clamping time, NYHA class ≥ 3 and urgency setting were significantly associated to death. Intra-hospital outcomes were acceptable regarding mortality and complications. Patients who need redo surgery on mitral bioprosthesis have an increased risk of post-operative pulmonary and gastrointestinal complications and mortality. Therefore the choice of mitral bioprosthesis at time of first surgery should be carefully evaluated.

Structural valve deterioration of the Labcor Dokimos aortic prosthesis: a single-centre experience

OBJECTIVES

The goal of this study was to assess the performance and incidence of the deterioration of the Labcor Dokimos bioprosthetic aortic valve.

METHODS

We performed a retrospective medical chart review of 116 patients who underwent surgical aortic valve replacement with the Labcor Dokimos aortic valve between 2010 and 2018. Abstracted data included patient demographic and echocardiographic data. Patients were divided into 2 groups: patients with structural valve deterioration (SVD) and patients without SVD.

RESULTS

Among the patients with complete follow-up (n = 95), 10 patients were excluded because they died within a year; 85 patients were included in the final analysis. Of the 85 patients, 32 (38%) developed SVD; 22 (26%) had severe SVD, 15 (18%) of whom underwent reintervention. The most common aetiology of SVD was severe central aortic regurgitation, which was detected in 91% of the patients who had severe SVD. The average time from operation to severe SVD was 4.7 years with a minimum of 1.5 years and a maximum of 7.9 years.

CONCLUSIONS

Bioprosthetic aortic valve deterioration due to severe aortic regurgitation is common and occurs early with the Labcor Dokimos valve. This occurrence needs to be furthered investigated in larger registries.

Latest Advances in Multimodality Imaging of Aortic Stenosis

Aortic stenosis is a common condition associated with major morbidity, mortality, and health-care costs. Nevertheless, we currently lack any effective medical therapies that can treat or prevent disease development or progression. Modern advances in echocardiography and CT have helped improve the assessment of aortic stenosis severity and monitoring of disease progression, whereas cardiac MRI informs on myocardial health and the development of fibrosis. In a series of recent studies, 18F-NaF PET/CT has been shown to assess valvular disease activity and progression, providing mechanistic insights that can inform potential novel therapeutic approaches. This review will examine the latest advances in the imaging of aortic stenosis and bioprosthetic valve degeneration and explore how these techniques can assist patient management and potentially accelerate novel therapeutic developments.

Transcatheter Valve-in-Valve Procedures for Bioprosthetic Valve Dysfunction in Patients With Rheumatic vs. Non-Rheumatic Valvular Heart Disease

Background: Bioprosthetic heart valve has limited durability and lower long-term performance especially in rheumatic heart disease (RHD) patients that are often subject to multiple redo operations. Minimally invasive procedures, such as transcatheter valve-in-valve (ViV) implantation, may offer an attractive alternative, although data is lacking. The aim of this study was to evaluate the baseline characteristics and clinical outcomes in rheumatic vs. non-rheumatic patients undergoing ViV procedures for severe bioprosthetic valve dysfunction.

Methods: Single center, prospective study, including consecutive patients undergoing transcatheter ViV implantation in aortic, mitral and tricuspid position, from May 2015 to September 2020. RHD was defined according to clinical history, previous echocardiographic and surgical findings.

Results: Among 106 patients included, 69 had rheumatic etiology and 37 were non-rheumatic. Rheumatic patients had higher incidence of female sex (73.9 vs. 43.2%, respectively; p = 0.004), atrial fibrillation (82.6 vs. 45.9%, respectively; p < 0.001), and 2 or more prior surgeries (68.1 vs. 32.4%, respectively; p = 0.001). Although, device success was similar between groups (75.4 vs. 89.2% in rheumatic vs. non-rheumatic, respectively; p = 0.148), there was a trend toward higher 30-day mortality rates in the rheumatic patients (21.7 vs. 5.4%, respectively; p = 0.057). Still, at median follow-up of 20.7 [5.1–30.4] months, cumulative mortality was similar between both groups (p = 0.779).

Conclusion: Transcatheter ViV implantation is an acceptable alternative to redo operations in the treatment of patients with RHD and severe bioprosthetic valve dysfunction. Despite similar device success rates, rheumatic patients present higher 30-day mortality rates with good mid-term clinical outcomes. Future studies with a larger number of patients and follow-up are still warranted, to firmly conclude on the role transcatheter ViV procedures in the RHD population.

Transoesophageal echocardiography-guided 'primary' valve-in-valve technique in cardiogenic shock: a case report

Background

Transcatheter aortic valve implantation inside a previously implanted bioprosthesis is an alternative treatment for patients with degenerated surgical aortic bioprosthesis (AB) at high surgical risk. Pre-operative computed tomography (CT) scan provides essential information to the procedure planning, although in case of acute presentation it is not always feasible.

Case summary

A 32-year-old man with history of surgical treatment of aortic coarctation and Bio-Bentall procedure was transferred to our department in cardiogenic shock with a suspected diagnosis of acute myocarditis. A transthoracic echocardiogram (TTE) revealed a severely impaired biventricular function and AB degeneration causing severe stenosis. It was decided to undertake an urgent trans-apical valve-in-valve (ViV) procedure. Due to haemodynamic instability, a preoperative CT scan was not performed and transoesophageal echocardiography (TOE) was the main intraprocedural guiding imaging technique. Neither intraprocedural nor periprocedural complications occurred. Serial post-procedural TTE exams showed good functioning of the bioprosthesis and progressive improvement of left ventricular ejection fraction. Patient was discharged from the hospital 8 days after the intervention.

Discussion

A patient with cardiogenic shock due to severe degeneration of the AB was treated with urgent transapical ViV procedure. In this case, where urgent ViV technique was needed, TOE appeared to be a crucial alternative to CT scan and allowed us to perform a successful procedure.

Meta-Analysis of Stroke and Mortality Rates in Patients Undergoing Valve-in-Valve Transcatheter Aortic Valve Replacement

Background

During the past decade, the use of transcatheter aortic valve replacement (TAVR) was extended beyond treatment‐naïve patients and implemented for treatment of degenerated surgical bioprosthetic valves. Selection criteria for either valve‐in‐valve (viv) TAVR or redo surgical aortic valve replacement are not well established, and decision making on the operative approach still remains challenging for the interdisciplinary heart team.

Methods and Results

This review was intended to analyze all studies on viv‐TAVR focusing on short‐ and mid‐term stroke and mortality rates compared with redo surgical aortic valve replacement or native TAVR procedures. A structured literature search and review process led to 1667 potentially relevant studies on July 1, 2020. Finally, 23 studies fulfilled the inclusion criteria for qualitative analysis. All references were case series either with or without propensity score matching and registry analyses. Quantitative synthesis of data from 8509 patients revealed that viv‐TAVR is associated with mean 30‐day stroke and mortality rates of 2.2% and 4.2%, respectively. Pooled data analysis showed no significant differences in 30‐day stroke rate, 30‐day mortality, and 1‐year mortality between viv‐TAVR and comparator treatment (native TAVR [n=11 804 patients] or redo surgical aortic valve replacement [n=498 patients]).

Conclusions

This review is the first one comparing the risk for stroke and mortality rates in viv‐TAVR procedures with native TAVR approach and contributes substantial data for the clinical routine. Moreover, this systematic review is the most comprehensive analysis on ischemic cerebrovascular events and early mortality in patients undergoing viv‐TAVR. In this era with increasing numbers of bioprosthetic valves used in younger patients, viv‐TAVR is a suitable option for the treatment of degenerated bioprostheses.

Valve-in-Valve Transcatheter Aortic Valve Replacement in a High-Risk Patient with a Biocor Bioprosthesis and a Flail Prosthetic Valve Leaflet

An 80-year-old woman with a history of surgical aortic valve replacement with a 21 mm St. Jude Medical Biocorporcine aortic valve 14 years prior presented with New York Heart Association (NYHA) class III symptoms, severeaortic insufficiency from a degenerated prosthesis, and a large echocardiographic mobile mass representing a highlymobile prosthetic leaflet. The patient worsened to NYHA class IV symptoms despite medical management. The Societyof Thoracic Surgery mortality risk score was extremely high. However, a valve-in-valve transcatheter aortic valve replacement (TAVR) was found to be a reasonable option. We used a 20 mm SAPIEN 3 Ultra value (Edwards Lifesciences Inc., Irvine, CA, USA) with a SENTINEL embolic protection device (Boston Scientific, Marlborough, MA, USA). During valve deployment, the echocardiographic mobile mass was visually pinned between the new TAVR valve and the surgical bioprosthetic valve. No large embolic debris was noted within the embolic protection device, and the patient remained without any new focal neurologic deficits in the perioperative period and at the 30-day follow-up. The severe aortic insufficiency resolved, and the patient clinically improved to NYHA class II symptoms.

Early detection of transcatheter heart valve dysfunction

Introduction: Transcatheter aortic valve implantation therapy is spreading rapidly, representing the standard of care in inoperable and high-risk patients, and a valid alternative in intermediate- and low-risk patients with severe symptomatic aortic stenosis. In this subset, the development and validation of noninvasive, quantitative, in vivo imaging modality, to monitor possible valve dysfunction is mandatory, in order to plan timely therapeutic interventions before the onset of symptoms.Areas covered: The implantation of transcatheter heart valves (THV) is increasing rapidly. As a consequence, THV dysfunction will become a major cause of cardiovascular morbidity after TAVI. Emergency repeat aortic valve replacement surgery is associated with a high rate of mortality compared with elective repeat surgery. In this context, early detection of THV dysfunction is therefore highly desirable. The review aims to examine the different diagnostic method to early detect THV dysfunction.Expert opinion: Most promising innovations in the diagnosis of early detection of THV dysfunction are evaluated, and the future outlook is explored. Waiting for upcoming evidence about the utility of CT, CMR, and PET on early detection of THV dysfunction, tailoring echocardiogram follow-up based on patients' characteristics is the desirable approach.

Detection and Prediction of Bioprosthetic Aortic Valve Degeneration

BACKGROUND

Bioprosthetic aortic valve degeneration is increasingly common, often unheralded, and can have catastrophic consequences.

OBJECTIVES

The authors sought to assess whether 18F-fluoride positron emission tomography (PET)-computed tomography (CT) can detect bioprosthetic aortic valve degeneration and predict valve dysfunction.

METHODS

Explanted degenerate bioprosthetic valves were examined ex vivo. Patients with bioprosthetic aortic valves were recruited into 2 cohorts with and without prosthetic valve dysfunction and underwent in vivo contrast-enhanced CT angiography, 18F-fluoride PET, and serial echocardiography during 2 years of follow-up.

RESULTS

All ex vivo, degenerate bioprosthetic valves displayed 18F-fluoride PET uptake that colocalized with tissue degeneration on histology. In 71 patients without known bioprosthesis dysfunction, 14 had abnormal leaflet pathology on CT, and 24 demonstrated 18F-fluoride PET uptake (target-to-background ratio 1.55 [interquartile range (IQR): 1.44 to 1.88]). Patients with increased 18F-fluoride uptake exhibited more rapid deterioration in valve function compared with those without (annualized change in peak transvalvular velocity 0.30 [IQR: 0.13 to 0.61] vs. 0.01 [IQR: -0.05 to 0.16] ms-1/year; p < 0.001). Indeed 18F-fluoride uptake correlated with deterioration in all the conventional echocardiographic measures of valve function assessed (e.g., change in peak velocity, r = 0.72; p < 0.001). Each of the 10 patients who developed new overt bioprosthesis dysfunction during follow-up had evidence of 18F-fluoride uptake at baseline (target-to-background ratio 1.89 [IQR: 1.46 to 2.59]). On multivariable analysis, 18F-fluoride uptake was the only independent predictor of future bioprosthetic dysfunction.

CONCLUSIONS

18F-fluoride PET-CT identifies subclinical bioprosthetic valve degeneration, providing powerful prediction of subsequent valvular dysfunction and highlighting patients at risk of valve failure. This technique holds major promise in the diagnosis of valvular degeneration and the surveillance of patients with bioprosthetic valves. (18F-Fluoride Assessment of Aortic Bioprosthesis Durability and Outcome [18F-FAABULOUS]; NCT02304276).

1-Year Results in Patients Undergoing Transcatheter Aortic Valve Replacement With Failed Surgical Bioprostheses

OBJECTIVES

This study evaluated the safety and effectiveness of self-expanding transcatheter aortic valve replacement (TAVR) in patients with surgical valve failure (SVF).

BACKGROUND

Self-expanding TAVR is superior to medical therapy for patients with severe native aortic valve stenosis at increased surgical risk.

METHODS

The CoreValve U.S. Expanded Use Study was a prospective, nonrandomized study that enrolled 233 patients with symptomatic SVF who were deemed unsuitable for reoperation. Patients were treated with self-expanding TAVR and evaluated for 30-day and 1-year outcomes after the procedure. An independent core laboratory was used to evaluate serial echocardiograms for valve hemodynamics and aortic regurgitation.

RESULTS

SVF occurred through stenosis (56.4%), regurgitation (22.0%), or a combination (21.6%). A total of 227 patients underwent attempted TAVR and successful TAVR was achieved in 225 (99.1%) patients. Patients were elderly (76.7 ± 10.8 years), had a Society of Thoracic Surgeons Predicted Risk of Mortality score of 9.0 ± 6.7%, and were severely symptomatic (86.8% New York Heart Association functional class III or IV). The all-cause mortality rate was 2.2% at 30 days and 14.6% at 1 year; major stroke rate was 0.4% at 30 days and 1.8% at 1 year. Moderate aortic regurgitation occurred in 3.5% of patients at 30 days and 7.4% of patients at 1 year, with no severe aortic regurgitation. The rate of new permanent pacemaker implantation was 8.1% at 30 days and 11.0% at 1 year. The mean valve gradient was 17.0 ± 8.8 mm Hg at 30 days and 16.6 ± 8.9 mm Hg at 1 year. Factors significantly associated with higher discharge mean aortic gradients were surgical valve size, stenosis as modality of SVF, and presence of surgical valve prosthesis patient mismatch (all p < 0.001).

CONCLUSIONS

Self-expanding TAVR in patients with SVF at increased risk for surgery was associated with a low 1-year mortality and major stroke rate, significantly improved aortic valve hemodynamics, and low rates of moderate and no severe residual aortic regurgitation, with improved quality of life.

Transcatheter heart valve in valve implantation with Edwards SAPIEN bioprosthetic valve for different degenerated bioprosthetic valve positions (First Iranian ViV report with mid-term follow up)

Introduction: After early successful experience with transcatheter aortic valve replacement (TAVR), concept of transcatheter implantation of a new valve within a failing bioprosthetic valve emerged. Valve-in-valve (ViV) implantation seems to be a simpler option for high risk surgical patients.

Methods: We performed five ViV procedures in different valve positions. We included patients with failing bioprosthetic valves with high surgical risk due to concomitant comorbidities. We performed 2 transapical ViV procedures for failing mitral bioprosthetic valves, 1 transfemoral procedure for failing pulmonary valve and 2 transfemoral ViV implantation for failing tricuspid bioprosthetic valves.

Results: The procedures were successfully completed in all 5 cases with initial excellent fluoroscopic and echocardiographic verification. There was no valve embolization or paravalvular leakage in any of the cases. Transcatheter valve function was appropriate with echocardiography. Post procedural clinical adverse events like pleural effusion and transient ischemic attack were managed successfully. In midterm follow up all cases remained in appropriate functional class except from the transcatheter pulmonary valve which became moderately stenotic and regurgitant.

Conclusion: As the first Iranian all-comers case series with midterm follow up for ViV implantation, we had no mortality. Interestingly none of our patients had neurologic sequelae after the procedure. Midterm follow up for our patients was acceptable with good functional class and appropriate echocardiographic findings. Due to high surgical risk of the redo procedure after failing of a bioprosthetic valve especially in elderly patients with comorbidities, ViV implantation would be a good alternative to surgery for this high risk group.

A Unique Hybrid Approach to Complex Re-Do Aortic Root Surgery

BACKGROUND

We present the case of a 23-year-old male with ventriculo-aortic dehiscence and a retrosternal false aneurysm communicating to the left ventricular outflow tract (LVOT) and ascending aorta. His history included aortic valve replacement (AVR) and mitral valve (MV) repair remotely, followed by two further operations for endocarditis and aortic root abscess.

METHODS

The risk associated with the redo surgery required detailed planning and innovative techniques to allow it to be performed safely. These included femoral cannulation for cardiopulmonary bypass, venting the left ventricular apex via a small left anterior thoracotomy, use of a CODA^® (COOK Medical, Bloomington USA) balloon to occlude the distal ascending aorta (placed via left brachial artery) and finally, the use of a PROPLEGE^® (Edwards Lifesciences, Irvine, USA) retrograde cardioplegia cannula (placed via right internal jugular vein).

Incremental Prognostic Use of Left Ventricular Global Longitudinal Strain in Asymptomatic/Minimally Symptomatic Patients With Severe Bioprosthetic Aortic Stenosis Undergoing Redo Aortic Valve Replacement

BACKGROUND

With improved survival of patients undergoing primary bioprosthetic aortic valve replacement (AVR), reoperation to relieve severe prosthetic aortic stenosis (PAS) is increasing. Timing of redo surgery in asymptomatic/minimally symptomatic patients remains controversial. Left ventricular (LV) global longitudinal strain (GLS) is a marker of subclinical LV dysfunction. In asymptomatic/minimally symptomatic patients with severe PAS undergoing redo AVR, we sought to determine whether LV-GLS provides incremental prognostic use.

METHODS AND RESULTS

We studied 191 patients with severe bioprosthetic PAS (63±16 years, 58% men) who underwent redo AVR between 2000 and 2012 (excluding mechanical PAS, severe other valve disease transcatheter AVR, and LV ejection fraction <50%). Society of Thoracic Surgeons score was calculated. Standard echocardiography data were obtained. LV-GLS was measured on 2-, 3-, and 4-chamber views using velocity vector imaging. Severe PAS was defined as aortic valve area <0.8 cm², mean aortic valve gradient ≥40 mm Hg, and dimensionless index <0.25. A composite outcome of death and congestive heart failure admission was recorded. At baseline, mean Society of Thoracic Surgeons score, LV ejection fraction, mean aortic valve gradients, and right ventricular systolic pressure were 7±6, 58±6%, 54±10 mm Hg and 40±14 mm Hg, whereas 50% had >2+ aortic regurgitation. Median LV-GLS was -14.2% (-11.4, -17.1%). At 4.2±3 years, 41 (22%) patients met the composite end point (2.5% deaths and 1% strokes at 30 days postoperatively). On multivariable Cox survival analysis, LV-GLS was independently associated with longer-term composite events (hazard ratio, 1.21; 95% confidence interval, 1.10-1.33), P<0.01. The C statistic for the clinical model (Society of Thoracic Surgeons score, degree of aortic regurgitation, and right ventricular systolic pressure) was 0.64 (95% confidence interval 0.54-0.79), P<0.001. Addition of LV-GLS to the clinical model increased the C statistic significantly to 0.71 (95% confidence interval 0.58-0.81), P<0.001.

CONCLUSIONS

In asymptomatic/minimally symptomatic patients with severe bioprosthetic PAS undergoing redo AVR, baseline LV-GLS provides incremental prognostic use over established predictors and could potentially aid in surgical timing and risk stratification.

Role of Echocardiography Before Transcatheter Aortic Valve Implantation (TAVI)

Aortic stenosis (AS) is the most common primary valve disorder in the elderly with an increasing prevalence; transcatheter aortic valve implantation (TAVI) has become an accepted alternative to surgical aortic valve replacement (AVR) in the high risk or inoperable patient. Appropriate selection of patients for TAVI is crucial and requires a multidisciplinary approach including cardiothoracic surgeons, interventional cardiologists, anaesthetists, imaging experts and specialist nurses. Multimodality imaging including echocardiography, CT and MRI plays a pivotal role in the selection and planning process; however, echocardiography remains the primary imaging modality used for patient selection, intra-procedural guidance, post-procedural assessment and long-term follow-up. The contribution that contemporary transthoracic and transoesophageal echocardiography make to the selection and planning of TAVI is described in this article.

The future of transcatheter aortic valve implantation

Since the introduction of transcatheter aortic valve implantation (TAVI) into clinical practice, the treatment of aortic stenosis has changed dramatically. In the past, medical therapy with or without balloon aortic valvuloplasty was the only option for inoperable patients. More recently, TAVI has become the treatment of choice for these patients and the preferred alternative for high-risk operable patients. Surgical aortic valve replacement (SAVR) currently remains the gold standard for patients at low or intermediate operative risk. As randomized trials have demonstrated comparable results between TAVI and SAVR in the high-risk population, there is now a clear trend towards performing TAVI even in intermediate-risk patients while awaiting the results of randomized trials in that population. Nevertheless, there are still questions regarding TAVI involving paravalvular leak (PVL), stroke, pacemaker requirements, and durability that remain to be more definitively answered before TAVI can routinely be performed in a broader, lower risk population. Improvements in patient selection, imaging, and second and third generation devices have decreased the incidence of PVLs and vascular complications that followed the earliest TAVI procedures, but the rates of perioperative stroke and permanent pacemaker implantation must still be addressed. Furthermore, the long-term durability of TAVI devices and a role for post-procedure antithrombotic management remain unanswered. Until these questions are more clearly answered, it is the Heart Team's task to determine the optimal treatment for each patient based on risk scores, frailty metrics, comorbidities, patient preference, and potential for improvement in quality of life.

Artificial aortic valve dysfunction due to pannus and thrombus - different methods of cardiac surgical management

INTRODUCTION

Approximately 60 000 prosthetic valves are implanted annually in the USA. The risk of prosthesis dysfunction ranges from 0.1% to 4% per year. Prosthesis valve dysfunction is usually caused by a thrombus obstructing the prosthetic discs. However, 10% of prosthetic valves are dysfunctional due to pannus formation, and 12% of prostheses are damaged by both fibrinous and thrombotic components. The authors present two patients with dysfunctional aortic prostheses who were referred for cardiac surgery. Different surgical solutions were used in the treatment of each case.

CASE STUDY 1

The first patient was a 71-year-old woman whose medical history included arterial hypertension, stable coronary artery disease, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and hypercholesterolemia; she had previously undergone left-sided mastectomy and radiotherapy. The patient was admitted to the Cardiac Surgery Department due to aortic prosthesis dysfunction. Transthoracic echocardiography revealed complete obstruction of one disc and a severe reduction in the mobility of the second. The mean transvalvular gradient was very high. During the operation, pannus covering the discs' surface was found. A biological aortic prosthesis was reimplanted without complications.

CASE STUDY 2

The second patient was an 87-year-old woman with arterial hypertension, persistent atrial fibrillation, and COPD, whose past medical history included gastric ulcer disease and ischemic stroke. As in the case of the first patient, she was admitted due to valvular prosthesis dysfunction. Preoperative transthoracic echocardiography revealed an obstruction of the posterior prosthetic disc and significant aortic regurgitation. Transesophageal echocardiography and fluoroscopy confirmed the prosthetic dysfunction. During the operation, a thrombus growing around a minor pannus was found. The thrombus and pannus were removed, and normal functionality of the prosthetic valve was restored.

CONCLUSIONS

Precise and modern diagnostic methods facilitated selection of the treatment method. However, the intraoperative view also seems to be crucial in individualizing the surgical approach.

Indications for transcatheter aortic valve implantation--now and next?

Aortic stenosis (AS) is the most common valvular pathology and its prevalence is expected to increase rapidly in coming decades as a consequence of the increasingly elderly population. Without treatment, severe symptomatic AS has a very poor prognosis with a mortality of 50% at two years. Whilst surgical aortic valve replacement is the gold standard treatment, a significant minority of patients are deemed inoperable and declined surgery due to prohibitively high risk. The advent of transcatheter aortic valve implantation (TAVI) has revolutionised their treatment. In this review, we discuss current indications for TAVI, other applications of this technology and future indications.

Minimally invasive reoperative aortic valve replacement: a systematic review and meta-analysis

BACKGROUND

With prolonged life expectancy and more frequent use of biological prostheses, an increasingly higher proportion of patients are undergoing aortic valve replacement (AVR) after previous sternotomy. We critically appraised the quantity and quality of evidence to demonstrate the efficacy and safety of the minimally invasive (MIrAVR) versus conventional (CrAVR) approaches for reoperative AVR.

METHODS

Electronic searches were performed using six databases from their inception to April 2014. Relevant studies utilizing a MIrAVR were identified. Data were extracted and analyzed according to predefined clinical endpoints.

RESULTS

Four single-arm and seven comparative observational studies including a total of 441 MIrAVR patients were included for quality assessment, data extraction and analysis. In-hospital mortality ranged from 0-9.5%, and was similar between the MIrAVR and CrAVR groups (RR, 0.77; 95% CI, 0.39-1.54; P=0.46). Stroke rates ranged from 2.6-8% and were also similar between the two cohorts. The rates of pacemaker implantation, renal failure and reoperation for bleeding were not significantly different between the two groups. There were no reports of myocardial infarctions in the included studies. No significant difference in hospital stay was observed for the MIrAVR versus CrAVR group.

CONCLUSIONS

The current literature suggests that MIrAVR has similar efficacy and mortality outcomes compared to CrAVR without compromise to myocardial protection or hospitalization duration. It appears to be a valid alternative option for patients requiring reoperative AVR.

Influence of prosthesis type on long-term survival after re-replacement of aortic valve prosthesis

BACKGROUND

The purpose of this study is to examine the influence of the prosthesis type on early mortality and long-term survival after re-replacement of aortic valve prosthesis, especially in patients over 60 years old.

METHODS

Late outcome of 223 patients who underwent a reoperation on the aortic valve and received a mechanical (mechanical group) or biological (biological group) heart valve prosthesis at a single institution were analyzed for survival and major valve-related complications, including structural valve deterioration, thromboembolism, hemorrhage, further reoperation, and valve-related mortality.

RESULTS

Preoperative New York Heart Association class IV (P = 0.001), emergency procedure (P = 0.002), and endocarditis (P = 0.025) were significant risk factors for 30-day mortality rates, which were 8.4 % and 12.5 %, respectively (mechanical versus biological group, P = 0.361). A subanalysis of elective patients revealed a low risk of 30-day mortality of 2.4 % and 1.8 %, respectively. Event-free survival was comparable at 5 years (73.9% ± 3.6% versus 70.5% ± 6.5%, mechanical versus biological group) and 10 year (49.7% ± 5.0% versus 35.3% ± 9.8%, mechanical versus biological group). In a propensity-matched subanalysis, survival and event-free survival were comparable at 5 and 10 years in both groups.

CONCLUSION

The type of aortic valve prosthesis did not affect early outcome and late survival in patients who underwent valve replacement, and therefore, the current strategy favoring a biological aortic valve prosthesis for patients aged over 60 years in first-time operations could also be applied in re-replacement.

Future perspectives in transcatheter aortic valve implantation

Transcatheter aortic valve replacement (TAVR) constitutes a relatively new treatment option for the patients with severe symptomatic aortic stenosis. Evidence from registries and randomized control trials has underscored the value of this treatment in inoperable and high risk populations, while new developments in valve technology and TAVR enabling devices have reduced the risk of complications, simplified the procedure, and broadened the applications of this therapy. The initial promising clinical results and the potential of an effective less invasive treatment of aortic stenosis has not only created high expectations but also the need to address the pitfalls of TAVR technology. The evolving knowledge concerning the groups of patients who would benefit from this treatment, the limited long term follow-up data, the concerns about devices' long term durability, and the severity of complications remain important caveats which restrict the widespread clinical adoption of TAVR. The aim of this review article is to present the recent advances, highlight the limitations of TAVR technology, and discuss the future perspectives in this rapidly evolving field.

Clinical outcomes of redo valvular operations: a 20-year experience

BACKGROUND

A higher operative mortality rate has been reported after redo valvular procedures than after the primary operation.

METHODS

Outcomes of 330 consecutive patients undergoing 433 redo valvular operations at our institute during a 20-year period (January 1990 to December 2010) were reviewed retrospectively. The mean follow-up was 6.4 years (range, 0.05 to 1.3 years). Logistic regression analysis was used to identify factors associated with hospital death.

RESULTS

The overall hospital mortality rate was 6.7% (29 of 433 procedures). Logistic regression analysis identified only advanced New York Heart Association (NYHA) class as an independent predictor of hospital death. Overall survival at 5, 10, and 15 years was 83.6%±2.2%, 70.7%±3.4%, and 61.5%±4.5%, respectively. The 5-, 10-, and 15-year survivals for the first redo vs more than second redo groups were 86.5%±2.4% vs 74.7%±5.5%, 71.8%±3.9% vs 66.8%±6.6%, and 60.2%±5.7% vs 63.1%±7.2%, respectively (log-rank P=0.505). The 5- and 10-year survivals for NYHA class I/II vs III/IV patients were 91.5%±2.1% vs 70.4%±4.5% and 77.8%±4.1% vs 58.5%±5.6%, respectively (log-rank p<0.005).

CONCLUSIONS

Redo valvular operation in NYHA class III/IV patients is associated with high hospital death and poor long-term survival. To achieve low hospital death and good long-term survival, redo operations, including more than third redo operations, should be performed in patients with lower NYHA class.

Valve-in-valve transcatheter aortic valve implantation for degenerated bioprosthetic heart valves

OBJECTIVES

We sought to analyze outcomes of patients with degenerated surgically implanted bioprosthetic heart valves undergoing valve-in-valve (viv) transcatheter aortic valve implantation (TAVI).

BACKGROUND

Redo cardiac surgery for degenerated bioprosthetic heart valves is associated with increased risks, particular in elderly patients with comorbidities. For these patients, TAVI may be an attractive, less invasive treatment option.

METHODS

Data from 47 patients age 64 to 97 years (logistic euroSCORE: 35.0 ± 18.5%) undergoing transfemoral (n = 25) or transapical (n = 22) viv-TAVI for failed bioprosthetic aortic valves 113 ± 65 months after initial surgery at 9 clinical sites in Germany and Switzerland were analyzed.

RESULTS

Valve-in-valve TAVI was technically successful in all patients, with 2 patients requiring bailout implantation of a second TAVI prosthesis for severe regurgitation during the procedure. There was 1 procedural death as the result of low-output failure. Valvular function after viv-TAVI was excellent with respect to valve competence, but increased transvalvular gradients ≥20 mm Hg were noted in 44% of patients. Vascular access complications occurred in 6 (13%) patients, and 5 (11%) patients required new pacemaker implantation after viv-TAVI. Renal failure requiring dialysis occurred in 4 (9%) patients. Mortality at 30 days was 17% (1 procedural and 7 post-procedural deaths), with 3 of 8 fatalities the result of non-valve-related septic complications.

CONCLUSIONS

Valve-in-valve TAVI can be performed with high technical success rates, acceptable post-procedural valvular function, and excellent functional improvement. However, in these predominantly elderly high-risk patients with multiple comorbidities, viv-TAVI was associated with 17% mortality, often because of septic complications arising in the post-operative phase.

Patient selection for transcatheter aortic valve implantation: patient risk profile and anatomical selection criteria

Patient selection plays a crucial role in the success of transcatheter aortic valve implantation (TAVI). It requires meticulous attention to the smallest of details and needs to be performed in a systematic manner for every patient. In essence, the patient must be assessed from access to implantation site. Becoming over "complacent" and "routine" may lead to failure and impact patient safety. TAVI is indicated for high or prohibitive surgical risk patients with severe aortic stenosis. Some patients, however, are too high risk even for TAVI. In addition to patient risk evaluation, anatomical selection criteria need to be considered. Multimodality imaging, using a combination of angiography, echocardiography and multislice computed tomography, is necessary to determine the anatomical suitability for the procedure.

Transarterial Medtronic CoreValve System Implantation for Degenerated Surgically Implanted Aortic Prostheses

Background—

To assess the results of transcatheter aortic valve implantation (TAVI) using the Medtronic CoreValve System (MCS), through the transarterial approach, in high-risk patients with degenerated surgically implanted aortic bioprostheses (SP).

Methods and Results—

Of 241 patients who underwent TAVI, 10 (4%) had a degenerated SP. The approach was percutaneous transfemoral in 9 cases and surgical transaxillary in 1. Patients were age 75±10 years of age. All were in New York Heart Association classes III or IV and at high risk for repeated surgery. Seven patients had stented, 2 stentless, and 1 homograft SP. The failure mode was predominant regurgitation in 7 cases and stenosis (aortic valve area, 0.7±0.2 cm 2 ; mean gradient, 58±16 mm Hg) in 3. Based on the echographic measurements, 8 patients received a 26-mm, and 2 a 29-mm-diameter MCS. Procedural success rate was 100%. There was 1 in-hospital death, 1 stroke with moderate sequelae, and 1 pacemaker implantation. There were no other adverse events at 30 days. The mean postimplantation transprosthetic gradient was 13±7 mm Hg; periprosthetic regurgitation was absent or trivial in 9 cases and grade 2 in 1. After a median follow-up of 5 months, there were no additional adverse events. All but 1 of the hospital survivors were in New York Heart Association classes I or II.

Conclusions—

These results suggest that transarterial MCS implantation in degenerated SP is feasible and may lead to hemodynamic and clinical improvement in patients who are poor candidates for repeated surgery, pending confirmation in larger series with longer follow-up.

Transcatheter valve-in-valve implantation for failing bioprosthetic valves

Transcatheter valve implantation is becoming an alternative to conventional surgical valve replacement in patients at high surgical risk. While experience and acceptance with transcatheter techniques increased rapidly, transcatheter valve implantation within failing bioprostheses has emerged as a new concept (valve-in-valve implantation). Currently, the majority of prostheses implanted in patients are bioprosthetic valves that are expected to degenerate over time. Valve-in-valve implantation provides great utility in high-operative-risk patients since the mortality risk for reoperation can be significantly higher than for first-time isolated valve replacement. Although two current devices are CE Mark approved in Europe for implantation within native valves, off-label clinical implementation of valve-in-valve have been described in numerous case reports. In this article, we provide an overview of transcatheter valve implantation in failing bioprostheses with an emphasis on the aortic position.