Contemporary outcomes of composite aortic root replacement in elderly patients

Figure 4.

OBJECTIVES

We investigated the clinical and haemodynamic outcomes in elderly patients undergoing composite aortic root replacement.

METHODS

Between 2005 and 2017, 135 patients underwent aortic root surgery at our hospital. Of these 135 patients, 47 patients aged ≥65 years were included in this study. Pathologies included aneurysms in 31, chronic aortic dissection in 6, acute aortic dissection in 4 and other causes in 6 patients. A bioprosthesis was used in 27 and a mechanical valve in 20 patients. The mean age was 71.0 ± 4.3 years. The mean follow-up period was 61 ± 35 months. Follow-up echocardiographic data (average 48 months after surgery) were collected in 35 patients (74%).

RESULTS

The in-hospital mortality rate was 2.1% (1 patient). Seven late deaths occurred during follow-up. The 1-, 5- and 8-year overall survival was 93.6%, 82.9% and 82.9%, respectively. Infective endocarditis, Marfan syndrome and diabetes were independent predictors of poorer survival. During the follow-up, thromboembolism occurred in 1 patient, major bleeding events in 5 patients, or proximal reoperation for prosthetic valve endocarditis in 1 patient. The type of valve, mechanical or biological valve, did not affect late mortality and morbidity. Follow-up echocardiography revealed significantly improved left ventricular ejection fraction compared with that at discharge.

CONCLUSIONS

Composite aortic root replacement provided satisfactory midterm outcomes in patients aged ≥65 years. Further studies with a longer follow-up are warranted to evaluate late valve-related events.

Risk Factors for Mortality and Morbidity of Surgical Aortic Valve Replacement for Aortic Stenosis - Risk Model From a Japan Cardiovascular Surgery Database

Background: The aim of this study was to determine adequate indication for transcatheter aortic valve replacement (TAVR). We analyzed risk factors of surgical aortic valve replacement (SAVR) not only for mortality, but also for morbidity, including long hospital stay (≥90 days) and patient activity at discharge, in patients who underwent SAVR for aortic stenosis (AS).

Methods and Results: Using the Japan Adult Cardiovascular Surgery Database (JCVSD), 13,961 patients with or without coronary artery bypass grafting who underwent elective SAVR for AS were identified from January 2008 to December 2012. The hospital mortality rate was 3.1%. The percentage of patients who had long hospital stay (≥90 days) and who had moderately or severely decompressed activity at discharge (modified Rankin scale ≥4) was 2.9% and 6.5%, respectively. Eleven and 20 preoperative predictors of hospital mortality and morbidity, respectively, including long hospital stay and compromised status at discharge, were identified. Based on these risk factors, the risk model predicted hospital mortality (area under the curve [AUC], 0.732) and morbidity (AUC, 0.694).

Conclusions: Using JCVSD, a risk model of SAVR was developed for AS. This model can identify patients at high risk not only for mortality, but also for mortality and morbidity, including long hospital stay and status at discharge.

Hemodynamic performance and incidence of patient-prosthesis mismatch of small-sized Trifecta pericardial aortic valves

OBJECTIVES

Small-sized bioprosthetic valves are sometimes associated with suboptimal hemodynamic performance, leading to a patient-prosthesis mismatch. Trifecta pericardial valves are designed to improve hemodynamic performance. The purpose of this study was to investigate the hemodynamic properties of small-sized Trifecta valves and their efficacy in preventing a patient-prosthesis mismatch.

METHODS

This was a retrospective analysis of 108 patients undergoing surgical aortic valve replacement with a Trifecta valve of 23 mm or less in a single Japanese institution. The hemodynamic performance was evaluated with an echocardiography examination in all patients after surgery, and the development of a patient-prosthesis mismatch was judged with the measured in vivo indexed effective orifice area.

RESULTS

There was one early and seven late mortalities. There were no valve explants due to structural valve deterioration. Postoperative mean pressure gradients of 19-, 21-, and 23-mm valves were 15.1, 11.4, and 9.0 mmHg, respectively. The effective orifice area of 19-, 21-, and 23-mm valves was 1.41, 1.69, and 1.78 cm², respectively. Patient-prosthesis mismatch occurred in 14 patients (1 severe and 13 moderate) and the incidence was 13.0% (15.4% in 19 mm, 18.0% in 21 mm, and 3.3% in 23 mm).

CONCLUSIONS

The small-sized Trifecta valves showed excellent hemodynamic performance and were associated with a low incidence rate of patient-prosthesis mismatch.

Multidisciplinary team management of carcinoid heart disease

Carcinoid heart disease (CHD) is a consequence of valvular fibrosis triggered by vasoactive substances released from neuroendocrine tumours, classically in those with metastatic disease and resulting in tricuspid and pulmonary valve failure. CHD affects one in five patients who have carcinoid syndrome (CS). Valve leaflets become thickened, retracted and immobile, resulting most often in regurgitation that causes right ventricular dilatation and ultimately, right heart failure. The development of CHD heralds a significantly worse prognosis than those patients with CS who do not develop valvular disease. Diagnosis requires a low threshold of suspicion in all patients with CS, since symptoms occur late in the disease process and clinical signs are difficult to elicit. As a result, routine screening is recommended using the biomarker, N-terminal pro-natriuretic peptide, and regular echocardiography is then required for diagnosis and follow-up. There is no direct medical therapy for CHD, but the focus of non-surgical care is to control CS symptoms, reduce tumour load and decrease hormone levels. Valve surgery improves long-term outcome for those with severe disease compared to medical management, although peri-operative mortality remains at between 10 and 20% in experienced centres. Therefore, care needs to be multidisciplinary at all stages, with clear discussion with the patient and between teams to ensure optimum outcome for these often-complex patients.

Long-Term Functional and Structural Durability of Bioprosthetic Valves Placed in the Aortic Valve Position via Percutaneous Rout in Israel

There is limited organized "real life" data regarding the long-term structural and functional durability of transcatheter aortic valve implants, a topic of major importance. We assessed the 5-year structural and functional integrity outcomes following trans-catheter aortic valve implantation (TAVI) with both self-expandable and balloon-expandable prosthetic valve devices. This study included 450 consecutive patients who underwent TAVI for severe symptomatic aortic stenosis (AS) between September 2008 and December 2011. Data were acquired from a multicenter Israeli registry and the median follow up time was 5.6 years. In 184 patients (40.9%) who survived 5 years, prostheses displayed sustained hemodynamic performance, with average peak and mean aortic valve gradients of 16.2 ± 8.9 and 9.2 ± 6.6 mm Hg, respectively. Late structural valve deterioration was found in 22 (12.3%) patients. Of these, 16 (8.9%) experienced valve deterioration and 6 (3.3%) experienced valve failure. Among the 6 patients with bioprosthetic valve failure, only 3 underwent re-interventions. Bioprosthetic valve dysfunction occurred more frequently in patients with small valves (23 mm) and high peak and mean transvalvular gradients at baseline. In conclusion, a relatively low rate of valve deterioration or failure was noted in our long-term follow-up study after TAVI procedures with both the catheter-based self-expandable and balloon-expandable prosthetic valves.

Antithrombotic therapy and bleeding events after aortic valve replacement with a novel bioprosthesis

OBJECTIVE

Several recent-generation surgical tissue valves have been found to have bleeding rates exceeding rates recommended by regulatory bodies. We explored bleeding events using data from the Pericardial Surgical Aortic Valve Replacement (PERIGON) Pivotal Trial for the Avalus valve (Medtronic, Minneapolis, Minn) to examine whether this end point remains relevant for the evaluation of bioprostheses.

METHODS

Patients (n = 1115) underwent aortic valve replacement. Bleeding and thromboembolic event episodes in patients within 3 years postimplant were analyzed for frequency, timing, and severity, focusing on patients taking antiplatelet/anticoagulant medications at the time of the event. Clinical and hemodynamic outcomes are also reported.

RESULTS

At 3 years, the Kaplan-Meier cumulative probability estimate of all-cause death was 7.2% (cardiac, 3.6%; valve-related, 1.1%). The Kaplan-Meier cumulative probability estimates of all and major hemorrhage were 8.7% and 5.2%, respectively. Ninety-nine bleeding events occurred in 86 patients: most occurred >30 days postsurgery. Among the 51 late major bleeds, in 5 cases the patients were taking anticoagulant/antiplatelet medication for prophylaxis after surgical aortic valve replacement at the time of the event, whereas the remaining patients were taking medications for other reasons. Age (hazard ratio, 1.035; 95% confidence interval, 1.004-1.068), peripheral vascular disease (hazard ratio, 2.135; 95% confidence interval, 1.106-4.122), renal dysfunction (hazard ratio, 1.920; 95% confidence interval, 1.055-3.494), and antithrombotic medication use at the time of the event (hazard ratio, 1.417; 95% confidence interval, 1.048-1.915) were associated with late bleeds (major and minor).

CONCLUSIONS

Overall clinical outcomes demonstrated low mortality and few complications except for major bleeding. Most bleeding events occurred >30 days after surgery and in patients taking antiplatelet and/or anticoagulation for indications other than postimplant prophylaxis.

Transcatheter aortic valve replacement: clinical safety and performance data

Introduction: Patients with severe aortic stenosis and regurgitation who are inoperable or at high-risk for surgery can be treated with transcatheter aortic valve replacement (TAVR). The aim of this study was to provide a comprehensive overview of the literature of TAVR and reported clinical and performance outcomes. Areas covered: A total of 16 devices, described in 204 articles describing clinical and performance outcomes, were included. The most frequently observed outcome was 30-day mortality, ranging between 0-23%. Other commonly reported clinical outcomes were 30-day stroke, ranging between 0-14.3% and pacemaker implantation, ranging from 0-44.9%. The most common valve performance outcome was aortic valve regurgitation, however, mostly reported at 7 days follow-up. Next to a follow-up period of 30 days, numerous articles reported outcomes at 6 months and 1 year. The numbers of articles describing outcomes with a longer follow-up as well as including intermediate and low-risk patients were limited. Expert commentary: This literature review provided a clear overview of the reported clinical and performance outcomes of TAVR devices. Despite the frequently used VARC-2 definitions, we identified a huge variation across studies. Future studies using standardized definitions of study set-ups and outcomes are essential and might lead to better insights of TAVR.

Adjunct Pharmacotherapy After Transcatheter Aortic Valve Replacement: Current Status and Future Directions

Transcatheter aortic valve replacement (TAVR) is a validated treatment option for severe aortic stenosis. Ischemic and thrombotic complications remain important and strongly correlate with mortality. The optimal postprocedural antithrombotic strategy for prevention of thrombotic events remains unclear. The international guidelines for medical management following TAVR are discordant, allowing for significant variance in prescribing habits. The optimal treatment strategy has yet to be delineated. Clinical trials are ongoing to assess the risks and benefits of various strategies. We discuss the pathobiology and rationale for antithrombotic therapy after TAVR, review current evidence and guidelines, and offer a concise evidence-based approach to this subject.

Computational Optimization Study of Transcatheter Aortic Valve Leaflet Design Using Porcine and Bovine Leaflets

In this study, a Bayesian optimization (BO) based computational framework is developed to investigate the design of transcatheter aortic valve (TAV) leaflets and to optimize leaflet geometry such that its peak stress under the blood pressure of 120 mmHg is reduced. A generic TAV model is parametrized by mathematical equations describing its 2D shape and its 3D stent-leaflet assembly line. Material properties previously obtained for bovine pericardium (BP) and porcine pericardium (PP) via a combination of flexural and biaxial tensile testing were incorporated into the finite element (FE) model of TAV. A BO approach was employed to investigate about 1000 leaflet designs for each material under the nominal circular deployment and physiological loading conditions. The optimal parameter values of the TAV model were obtained, corresponding to leaflet shapes that can reduce the peak stress by 16.7% in BP and 18.0% in PP, compared with that from the initial generic TAV model. Furthermore, it was observed that while peak stresses tend to concentrate near the stent-leaflet attachment edge, optimized geometries benefit from more uniform stress distributions in the leaflet circumferential direction. Our analysis also showed that increasing leaflet contact area redistributes peak stresses to the belly region contributing to peak stress reduction. The results from this study may inspire new TAV designs that can have better durability.

How to treat severe symptomatic structural valve deterioration of aortic surgical bioprosthesis: transcatheter valve-in-valve implantation or redo valve surgery?

The optimal management of aortic surgical bioprosthesis presenting with severe symptomatic structural valve deterioration is currently a matter of debate. Over the past 20 years, the number of implanted bioprostheses worldwide has been rapidly increasing at the expense of mechanical prostheses. A large proportion of patients, however, will require intervention for bioprosthesis structural valve deterioration. Current options for older patients who often have severe comorbidities include either transcatheter valve-in-valve (TVIV) implantation or redo valve surgery. The emergence of TVIV implantation, which is perceived to be less invasive than redo valve surgery, offers an effective alternative to surgery for these patients with proven safety and efficacy in high-risk patient groups including elderly and frail patients. A potential caveat to this strategy is that results of long-term follow-up after TVIV implantation are limited. Redo surgery is sometimes preferable, especially for young patients with a smaller-sized aortic bioprosthesis. With the emergence of TVIV implantation and the long experience of redo valve surgery, we currently have 2 complementary treatment modalities, allowing a tailor-made and patient-orientated intervention. In the heart team, the decision-making should be based on several factors including type of bioprosthesis failure, age, comorbidities, operative risk, anatomical factors, anticipated risks and benefits of each alternative, patient's choice and local experience. The aim of this review is to provide a framework for individualized optimal treatment strategies in patients with failed aortic surgical bioprosthesis.

Hemodynamic Performances and Clinical Outcomes in Patients Undergoing Valve-in-Valve Versus Native Transcatheter Aortic Valve Implantation

Valve-in-valve (ViV) transcatheter aortic valve implantation (TAVI) emerged has a less invasive treatment than surgery for patients with degenerated bioprosthesis. However, few data are currently available regarding results of ViV versus TAVI in native aortic valve. We aimed to compare hemodynamic performances and 1-year outcomes between patients who underwent ViV procedure and patients who underwent non-ViV TAVI. This bicentric study included all patients who underwent aortic ViV procedure for surgical bioprosthetic aortic failure between 2013 and 2017. All patients who underwent TAVI were included in the analysis during the same period. ViV and non-ViV patients were matched with 1:2 ratio according to size, type of TAVI device, age (±5 years), sex, and STS score. Primary end point was hemodynamic performance including mean aortic gradient and aortic regurgitation at 1-year follow-up. A total of 132 patients were included, 49 in the ViV group and 83 in the non-ViV group. Mean age was 82.8 ± 5.9 years, 55.3% were female. Mean STS score was 5.2% ± 3.1%. Self-expandable valves were implanted in 78.8% of patients. At 1-year follow-up, aortic mean gradient was significantly higher in ViV group (18.1 ± 9.4 mm Hg vs 11.4 ± 5.4 mm Hg; p < 0.0001) and 17 (38.6%) patients had a mean aortic gradient ≥20 mm Hg vs 6 (7.8%) in the non-ViV group (p = 0.0001). Aortic regurgitation > grade 2 were similar in both groups (p = 0.71). In the ViV group, new pacemaker implantation was less frequent (p = 0.01) and coronary occlusions occurred only in ViV group (n = 2 [4.1%]). At 1-year follow-up, 3 patients (2.3%) died from cardiac cause, 1 (2.1%) in the ViV group vs 2 (2.4%) in the non-ViV group (p = 0.9). There was no stroke. In conclusion, compared with TAVI in native aortic stenosis, ViV appears as a safe and feasible strategy in patients with impaired bioprosthesis. As 1-year hemodynamic performances seem better in native TAVI procedure, long-term follow-up should be assessed to determinate the impact of residual stenosis on outcomes and durability.

Antithrombotic pharmacotherapy after transcatheter aortic valve implantation: an update

Introduction: Transcatheter aortic valve implantation (TAVI) is the treatment of choice for a large proportion of patients with severe aortic stenosis. Despite numerous technological and clinical advances, TAVI remains associated with thrombotic complications requiring antithrombotic pharmacotherapy, which exposes to the risk of bleeding, especially in elderly individuals. The optimal antithrombotic regimen following TAVI is uncertain and several investigations are ongoing. Areas covered: Clinical guidelines are mostly driven by observational trials and experts' opinions, thus resulting into low-grade level of evidence. The aim of the current review is to critically explore the epidemiology, pathophysiology and prognostic value of thrombotic and bleeding events after TAVI, and to review the current literature on antithrombotic strategies following the procedure. Expert opinion: Thrombotic and bleeding events remain major complications occurring in the frail population that is currently offered TAVI. Waiting for upcoming evidence from ongoing randomized clinical trials, tailoring antithrombotic therapies based on patients' characteristics, values and circumstances is a preferable approach.

Recipients with blood group A associated with longer survival rates in cardiac valvular bioprostheses

Background

Pigs/bovines share with humans some of the antigens present on cardiac valves. Two such antigens are: the major xenogenic Ag, “Gal” present in all pig/bovine very close to human B-antigen of ABO-blood-group system; the minor Ag, pig histo-blood-group AH-antigen identical to human AH-antigen and present by some animals. We hypothesize that these antigens may modify the immunogenicity of the bioprosthesis and also its longevity. ABO distribution may vary between patients with low (<6 years) and high (≥15 years) bioprostheses longevity.

Methods

Single-centre registry study (Paris, France) including all degenerative porcine bioprostheses (mostly Carpentier-Edwards 2nd/3rd generation heart valves) explanted between 1985 and 1998 and some bovine bioprostheses. For period 1998–2014, all porcine bioprostheses with longevity ≥13 years (follow-up ≥29 years). Important predictive factors for bioprosthesis longevity: number, site of implantation, age were collected. Blood group and other variables were entered into an ordinal logistic regression analysis model predicting valve longevity, categorized as low (<6 years), medium (6–14.9 years), and high (≥15 years).

Findings

Longevity and ABO-blood group were obtained for 483 explanted porcine bioprostheses. Mean longevity was 10.2 ± 3.9 years [0–28] and significantly higher for A-patients than others (P = 0.009). Using multivariate analysis, group A was a strong predictive factor of longevity (OR 2.09; P < 0.001). For the 64 explanted bovine bioprosthesis with low/medium longevity, the association, with A-group was even more significant.

Interpretation

Patients of A-group but not B have a higher longevity of their bioprostheses. Future graft-host phenotyping and matching may give rise to a new generation of long-lasting bioprosthesis for implantation in humans, especially for the younger population.

Fund

None.

Transcatheter aortic valve replacement in failed surgical valves

Aortic valve-in-valve is a less invasive alternative to surgical redo in the treatment of failed bioprosthetic valves. While only inoperable patients underwent the procedure before, operators currently offer it to those at lower risk and worldwide experience is in the thousands. Early mortality has diminished in recent analyses and improvements in symptoms and quality of life have been documented. Main considerations with aortic valve-in-valve include elevated postprocedural gradients, coronary obstruction and leaflet thrombosis. Risk factors for each of these adverse events have been described at length. Aortic valve-in-valve offers a safe and effective option in the management of failed bioprosthetic valves.

One-year clinical outcome with a novel self-expanding transcatheter heart valve

OBJECTIVES

To evaluate 1-year outcome using the ACURATE neo (Symetis S.A., a Boston Scientific Company, Ecublens, Switzerland) according to the updated Valve Academic Research Consortium (VARC-2) with emphasis on the composite endpoints "clinical efficacy after 30 days" and "time-related valve safety".

BACKGROUND

Initial reports on the clinical performance of patients treated with the ACURATE neo are promising; however, information regarding one-year outcome is scarce, especially with regard to the composite endpoints proposed by the VARC-2.

METHODS

One hundred and fifty one consecutive patients undergoing transfemoral transcatheter aortic valve replacement (TAVR) with the ACURATE neo for severe aortic valve stenosis were enrolled. Data were prospectively collected and event rates during follow-up were calculated as the Kaplan-Meier estimates.

RESULTS

Mean age was 81.1 ± 5.9 years and 49.7% (75/151) were female with a median logistic EuroScore of 13.8% [8.2-20.5]. Device success was achieved in 88.1% (133/151) and procedure related mortality was 0.7% (1/151). At one-year, all-cause mortality was 3.3% (5/151), while permanent pacemaker implantation occurred in 12.7% (19/151) of patients. The "clinical efficacy after 30 days" was observed in 24.8% (37/151), where the main contributor was symptom worsening in 14.8% (22/151) of cases. "Time-related valve safety" occurred in 22.0% (33/151) with structural valve deterioration as main contributor in 10.7% (16/151) of cases.

CONCLUSIONS

Using the ACURATE neo, we found a favorable safety profile with low all-cause mortality at 1 year. The reported VARC-2 defined composite endpoints at 1 year reveal low rates of "clinical efficacy after 30 days" and "time-related valve safety".

Statistical primer: methodology and reporting of meta-analyses

In modern medicine, the results of a comprehensive and methodologically sound meta-analysis bring the most robust, high-quality information to support evidence-based decision-making. With recent developments in newer meta-analytic approaches, iteration of statistical paradigms and software implementations, network and patient-level meta-analyses have recently gained popularity alongside conventional pairwise study-level meta-analyses. However, pitfalls are common in this challenging and rapidly evolving field of statistics. In this regard, guidelines have been introduced to standardize, strengthen and homogenize different aspects of conducting and reporting the results of a meta-analysis. Current recommendations advise a careful selection of the individual studies to be pooled, mainly based on the methodological quality and homogeneity in study designs. Indeed, even if a reasonable degree of variability across study results (namely, heterogeneity) can be accounted for with proper statistics (i.e. random-effect models), no adjustment can be performed in meta-analyses violating the issue of clinical validity and similarity across the included studies. In this context, this statistical primer aims at providing a conceptual framework, complemented by a practical example, for conducting, interpreting and critically evaluating meta-analyses.

Valve durability after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure to treat severe symptomatic aortic stenosis. While the TAVI procedure can be performed safely and provide excellent 5-year results, little is known about long-term durability. TAVI valves are composed of bioprosthetic leaflets are prone to deterioration, which are categorized as structural valve deterioration (SVD) and non-SVD. SVD refers to an intrinsic pathology of the leaflets or stent structure with mechanisms that include leaflet calcification, leaflet tear, stent fracture, or stent creep. Non-SVD processes include valve thrombosis, infective endocarditis and patient prosthesis mismatch. TAVI valves degenerate by similar mechanisms as bioprosthetic surgical aortic valves. Unique mechanisms that contribute to TAVI degeneration include valve crimpling, balloon expansion, stent under-expansion and valve thrombosis. The absence of a universally accepted definition of SVD poses a challenge in estimating valve durability. Traditional surgical bioprosthetic aortic valves have demonstrated excellent durability with clinically relevant SVD of 6.6% at 10-year follow up. Long-term durability of TAVI valves, however, remain poorly defined. From meta-analysis TAVI trials, SVD was estimated at 7% at 5 years. With iterative improvements in TAVI valve construction and deployment techniques, long-term durability may improve. Until long-term outcomes are better understood, TAVI should be used with caution in younger patients.

Complementary Role of the Computed Biomodelling through Finite Element Analysis and Computed Tomography for Diagnosis of Transcatheter Heart Valve Thrombosis

Introduction

The TAVR procedure is associated with a substantial risk of thrombosis. Current guidelines recommend catheter-based aortic valve implantation for prohibitive-high-risk patients with severe aortic valve stenosis but acknowledge that the aetiology and mechanism of thrombosis are unclear.

Methods

From 2015 to 2018, 607 patients with severe aortic valve stenosis underwent either self-expandable or balloon-expandable catheter-based aortic valve implantation at our institute. A complementary study was designed to support computed tomography as a predictor of complications using an advanced biomodelling process through finite element analysis (FEA). The primary evaluation of study was the thrombosis of the valve at 12 months.

Results

At 12 months, 546 patients had normal valvular function. 61 patients had THVT while 6 showed thrombosis and dislodgement with deterioration to NYHA Class IV requiring rehospitalization. The FEA biomodelling revealed a strong link between solid uncrushed calcifications, delayed dislodgement of TAVR and late thrombosis. We observed an interesting phenomenon of fibrosis/calcification originating at the level of the misplaced valve, which was the primary cause of coronary obstruction.

Conclusion

The use of cardiac CT and predictive biomodelling should be integrated into routine practice for the selection of TAVR candidates and as a predictor of negative outcomes given the lack of accurate investigations available. This would assist in effective decision-making and diagnosis especially in a high-risk cohort of patients.

Structural valve deterioration of bioprosthetic aortic valves: An underestimated complication

OBJECTIVES

Structural valve deterioration (SVD) remains a major bioprosthesis-related complication, as recently described for the Mitroflow valve (models LX and 12A) (LivaNova, London, United Kingdom). The real incidence of the SVD risk remains unclear, often due to methodologic pitfalls by systematically using the Kaplan-Meier estimator and/or the Cox model. In this report, we propose for the first time a precise statistical modeling of this issue.

METHODS

Five hundred sixty-one patients who underwent aortic valve replacement with the aortic Mitroflow valve between 2002 and 2007 were included. We used an illness-death model for interval-censored data. Median follow-up was 6.6 years; 103 cases of SVD were diagnosed.

RESULTS

The 4-year and 7-year SVD cumulative incidences after the first anniversary of surgery were 15.2% (95% confidence interval, 11.9-19.1) and 31.0% (95% confidence interval, 25.8-37.2), respectively. Female gender, dyslipidemia, chronic obstructive pulmonary disease, and severe patient-prosthesis mismatch were significant risk factors of SVD. The occurrence of SVD was associated with a 2-fold increase in the risk of death.

CONCLUSIONS

Appropriate statistical models should be used to avoid underestimating the SVD complication associated with worse long-term survival.

Expanding TAVI to Low and Intermediate Risk Patients

TAVI has become the standard treatment in patients at increased surgical risk and is increasingly being performed in patients at intermediate to low surgical risk. While non-inferiority has been demonstrated in intermediate risk patients, several challenges—particularly with regard to valve durability—need to be addressed before expansion to lower risk and younger patients can be recommended on a broad basis. Current trends, trials results, and remaining challenges are summarized and discussed in the light of updated treatment guidelines.

Clinical and echocardiographic follow-up of patients following surgical heart valve repair or replacement: a tertiary centre experience

International best practice guidelines recommend lifelong follow-up of patients that have undergone valve repair or replacement surgery and provide recommendations on the utilization of echocardiography during follow-up. However, such follow-up regimes can vary significantly between different centres and sometimes within the same centre. We undertook this study to determine the patterns of clinical follow-up and use of transthoracic echocardiography (TTE) amongst cardiologists in a large UK tertiary centre. In this retrospective study, we identified patients that underwent heart valve repair or replacement surgery in 2008. We used local postal codes to identify patients within our hospital's follow-up catchment area. We determined the frequency of clinical follow-up and use of transthoracic echocardiography (TTE) during the 9-year follow-up period (2009-2016 inclusive). Of 552 patients that underwent heart valve surgery, 93 (17%) were eligible for local follow-up. Of these, the majority (61/93, 66%) were discharged after their 6-week post-operative check-up with no further follow-up. Of the remaining 32 patients, there was remarkable heterogeneity in follow-up regimes and use of TTE. This variation did not correlate with the prosthesis type. In summary, the frequency of clinical follow-up and use of echocardiography is highly variable in contemporary practice. Many patients are inappropriately discharged back to their family doctor with no plans for hospital follow-up. These data further support the creation of dedicated specialist heart valve clinics to optimize patient care, ensure rational use of TTE and optimize adherence with best practice guidelines.

Mitroflow LXA structural deterioration following aortic valve replacement: a single-center experience

BACKGROUND

Concerns have been previously raised regarding the potential early degeneration of the Mitroflow (Sorin Group Italia, Saluggia, Vercelli, Italy) bioprostheses. We aimed to evaluate our clinical experience with the Mitroflow LXA prosthesis for aortic valve replacement.

METHODS

We prospectively analyzed data from 227 consecutive patients (133 males, mean age 73.9±9.2 years) implanted with the Mitroflow LXA between February 2007 and October 2011. Follow-up data were obtained by contacting the referring cardiologists. Kaplan-Meier curves were constructed for all-cause mortality, valve related mortality and structural valve degeneration (SVD). Multivariable analysis was conducted to identify SVD predictors.

RESULTS

Median follow-up time was 54.2±37.9 months and completeness of follow-up was 95%. Overall mortality in the entire series was at 31% (N.=71) and mortality from cardiac or unknown causes at 20% (N.=46). SVD occurred in 24 patients (10%) (median delay between implantation and diagnosis: 62.6 (36.5) months). Reintervention was required in 20 cases (13 redo surgery, 7 percutaneous transcatheter valve intervention). The 8 years actuarial global survival was 54.7±4.9%, freedom from valve related mortality 67.5±4.9% and freedom from SVD 72±8%. The estimated freedom from SVD was significantly (P=0.007) longer in larger prosthesis (diameter >21 mm, 77±11%) compared to the smaller devices (≤21 mm, 59±13%.). Multivariate analysis identified smaller prostheses and age at implantation as independent predictors of SVD.

CONCLUSIONS

The Mitroflow LXA showed evidence of early SVD in this cohort. A close follow-up of these patients is strongly advised.

Challenges When Expanding Transcatheter Aortic Valve Implantation to Younger Patients

The rapid expansion of transcatheter aortic valve implantation (TAVI) has been based upon robust clinical evidence derived from randomized controlled trials and large-scale international and national registries. Over the past decade, TAVI has evolved into a safe and effective procedure with predictable and reproducible outcomes. As a consequence, the TAVI technology is increasingly used to treat patients with a lower risk profile and the volume of TAVI now exceeds surgical aortic valve replacement (SAVR) in some countries. It may be anticipated that, in the near future, the majority of patients with severe symptomatic aortic valve stenosis will undergo TAVI as first line therapy, regardless of their age and risk profile. This article identifies some of the specific challenges that lie ahead when considering expansion of TAVI to younger patients.

Standardized Definition of Structural Valve Degeneration for Surgical and Transcatheter Bioprosthetic Aortic Valves

Bioprostheses are prone to structural valve degeneration, resulting in limited long-term durability. A significant challenge when comparing the durability of different types of bioprostheses is the lack of a standardized terminology for the definition of a degenerated valve. This issue becomes especially important when we try to compare the degeneration rate of surgically inserted and transcatheter bioprosthetic valves. This document, by the VIVID (Valve-in-Valve International Data), proposes practical and standardized definitions of valve degeneration and provides recommendations for the timing of clinical and imaging follow-up assessments accordingly. Its goal is to improve the quality of research and clinical care for patients with deteriorated bioprostheses by providing objective and strict criteria that can be utilized in future clinical trials. We hope that the adoption of these criteria by both the cardiological and surgical communities will lead to improved comparability and interpretation of durability analyses.

Expanding TAVI to Low and Intermediate Risk Patients

TAVI has become the standard treatment in patients at increased surgical risk and is increasingly being performed in patients at intermediate to low surgical risk. While non-inferiority has been demonstrated in intermediate risk patients, several challenges-particularly with regard to valve durability-need to be addressed before expansion to lower risk and younger patients can be recommended on a broad basis. Current trends, trials results, and remaining challenges are summarized and discussed in the light of updated treatment guidelines.