Comparison of apixaban versus aspirin for the prevention of latent bioprosthetic aortic valve thrombosis: study protocol for a prospective randomized trial

BACKGROUND

The optimal antithrombotic strategy early after aortic valve replacement surgery with a biological valve remains controversial due to lack of high-quality evidence. Either oral anticoagulants or acetylsalicylic acid should be considered for the first 3 months. Hypo-attenuated leaflet thickening on cardiac computed tomography has been associated with latent bioprosthetic valve thrombosis and may be prevented with anticoagulation. We hypothesize that anticoagulation with apixaban is superior to single antiplatelet therapy with acetylsalicylic acid in reducing hypo-attenuated leaflet thickening of bioprosthetic aortic valve prostheses.

METHODS

In this prospective, open-label, randomized trial, patients undergoing isolated aortic valve replacement surgery with rapid deployment bioprosthetic valves will be randomized. The treatment group will receive 5 mg of apixaban twice a day for the first 3 months and 100 mg of acetylsalicylic acid thereafter. The control group will be administered 100 mg of acetylsalicylic acid once a day, indefinitely. After the 3-month treatment period, a contrast-enhanced electrocardiogram-gated cardiac computed tomography will be performed to identify hypo-attenuated leaflet thickening of the bioprosthetic valve. The primary objective of the study is to assess the impact of apixaban on the prevention of hypo-attenuated leaflet thickening at 3 months. The secondary and exploratory endpoints will be clinical outcomes and safety profiles of the two strategies.

DISCUSSION

Antithrombotic therapy after aortic valve replacement is used to prevent valve thrombosis and systemic thromboembolism. Latent bioprosthetic valve thrombosis is a precursor of clinically significant prosthetic valve dysfunction or thromboembolic events. The hallmark feature of latent bioprosthetic valve thrombosis is hypo-attenuated leaflet thickening on cardiac computed tomography. Subclinical leaflet thrombosis occurs frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. There is no evidence on the effect of direct oral anticoagulants on the incidence of hypo-attenuated leaflet thickening after surgical aortic valve replacement with rapid deployment bioprostheses.

TRIAL REGISTRATION

ClinicalTrials.gov NCT06184113. Registered on December 28, 2023.

Sutureless bioprosthesis for aortic valve replacement: Surgical and clinical outcomes

BACKGROUND

Aortic valve stenosis is the most common adult valve disease in industrialized countries. The aging population and the increase in comorbidities urge the development of safer alternatives to the current surgical treatment. Sutureless bioprosthesis has shown promising results, especially in complex procedures and in patients requiring concomitant surgeries.

OBJECTIVES

Assess the clinical and hemodynamic performance, safety, and durability of the Perceval® prosthetic valve.

METHODS

This single-center retrospective longitudinal cohort study collected data from all adult patients with aortic valve disease who underwent aortic valve replacement with a Perceval® prosthetic valve between February 2015 and October 2020. Of the 196 patients included (mean age 77.20 ± 5.08 years; 45.4% female; mean EuroSCORE II 2.91 ± 2.20%), the majority had aortic stenosis.

RESULTS

Overall mean cross-clamp and cardiopulmonary bypass times were 33.31 ± 14.09 min and 45.55 ± 19.04 min, respectively. Mean intensive care unit and hospital stay were 3.32 ± 3.24 days and 7.70 ± 5.82 days, respectively. Procedural success was 98.99%, as two explants occurred. Four valves were reimplanted due to intraoperative misplacement. Mean transvalvular gradients were 7.82 ± 3.62 mmHg. Pacemaker implantation occurred in 12.8% of patients, new-onset atrial fibrillation in 21.9% and renal replacement support was necessary for 3.1%. Early mortality was 2.0%. We report no structural valve deterioration, strokes, or endocarditis, and one successfully treated valve thrombosis.

CONCLUSIONS

Our study confirms the excellent clinical and hemodynamic performance and safety of a truly sutureless aortic valve, up to a 5-year follow-up. These results were consistent in isolated and concomitant interventions, solidifying this device as a viable option for the treatment of isolated aortic valve disease.

Perceval S valve empire: healing the Achilles' heel of sutureless aortic valves

Aortic valve replacement is the treatment of choice concerning aortic valve disease. Excellent short- and longterm clinical results are reported. Patients referred for aortic valve replacement are getting older and older, so bioprosthetic valves play a more central role worldwide. However, patient comorbidities are also increased more often rendering patients unsuitable for open conventional aortic valve replacement. As a result, transcatheter aortic valve implantation has become the treatment of choice in patients at very high surgical risk. However, the percutaneous technique is related to major disadvantages provided that the diseased native valve is left in place. Its durability is also uncertain. More recently, sutureless Perceval S valve bioprosthesis has gained ground in the field of aortic stenosis therapy filling the gap between conventional aortic valve replacement and transcatheter approach. Excellent haemodynamic and clinical results are reported. Its deployment is performed under direct view and ischemic and overall operative times are significantly decreased. Five-year follow-up results are also optimal. However, the "Achilles' heel" of sutureless technology is increased rates of postoperative permanent pacemaker implantation requirement compared to conventional approach. The incidence of this complication varies in literature. Patient-related factors such as preoperative conduction disorders, older age and short membranous septum are predictors of postoperative pacemaker requirement. However, several technical modifications with regard to manufacturer recommendations can be adopted to mitigate this complication. Appropriate annular decalcification, higher guiding sutures placement, reduced balloon pressure and duration and avoiding of oversizing can contribute to prevent from this complication.

Rapid-deployment aortic valve replacement in high-risk patients: A case-control study

Introduction: Aortic valve stenosis is the most frequent cardiac valve pathology in the western world. In high-risk patients, conventional aortic valve replacement (C-AVR) carries high rates of morbidity and mortality. In the last few years, rapid-deployment valves (RDV) have been developed to reduce the surgical risks. In this work, we aimed to compare the mid-term outcomes of rapid-deployment AVR (RD-AVR) with those of the C-AVR in high-risk patients.

Methods: This retrospective case-control study identified 23 high-risk patients who underwent RD-AVR between 12/2015 to 01/2018. The study group was compared with a control group of 46 patients who were retrospectively selected from a database of 687 C-AVR patients from 2016 to 2017 which matched with the study group for age and Euro SCORE II.

Results: RD-AVR group presented more cardiovascular risk factors. Euro SCORE II was higher in the RD-AVR group (P =0.06). In the RD-AVR group, we observed significantly higher mean prosthetic size (P <0.001). In-hospital mortality was zero in RD-AVR group versus 2 deaths in C-AVR group. Hospital stay was longer in the RD-AVR group with statistical significance (P =0.03). In the group AVR with associated cardiac procedures, while comparing subgroups RD-AVR versus C-AVR, early mean gradient was lower in the first cited (P =0.02). The overall mean follow-up was 10.9 ± 4.3 months.

Conclusion: The RD-AVR technique is reliable and lead to positive outcomes. This procedure provides a much larger size with certainly better flow through the aortic root. It is an alternative to C-AVR in patients recognized to be surgically fragile.

Mid-term assessment of structural valve deterioration of perceval S sutureless prosthesis using the last European consensus definition

OBJECTIVES

Durability of sutureless aortic bioprosthetic valves remains a major issue. The aim of this study was to assess structural valve deterioration (SVD) and bioprosthetic valve failure (BVF) of the Perceval bioprosthesis using the new proposed standardized definitions.

METHODS

All patients who underwent aortic valve replacement with sutureless Perceval S prostheses up to September 2016 were included. Clinical and echocardiographic follow-up was performed. New standardized definitions were used to assess the durability of sutureless bioprosthetic valves. From 2013 to 2016, 214 patients were included.

RESULTS

The mean age and EuroSCORE II were 79 years and 2.74. Thirty-day mortality was 0.47%. The survival rate was 96.8%, 88.1% and 85.7% at 1, 3 and 4 years, respectively. The median echocardiographic follow-up was 3.28 years. The mean pressure gradient was 11.3 mmHg. No cases showed evidence of severe SVD, 17 patients had moderate SVD with a mean pressure gradient of 24 mmHg and 8 patients had definite late BVF. The incidence of moderate SVD and BVF at 4 years was 8.8% and 2.9%, respectively.

CONCLUSIONS

Mid-term follow-up to 6.3 years after aortic valve replacement with the Perceval bioprosthesis documents favourable haemodynamic and clinical outcomes and low rates of SVD and BVF.

Indications and predictors for pacemaker implantation after isolated aortic valve replacement with bioprostheses: the CAREAVR study

OBJECTIVES

We sought to study the indications, long-term occurrence, and predictors of permanent pacemaker implantation (PPI) after isolated surgical aortic valve replacement with bioprostheses.

METHODS

The CAREAVR study included 704 patients (385 females, 54.7%) without a preoperative PPI (mean ± standard deviation age 75 ± 7 years) undergoing isolated surgical aortic valve replacement at 4 Finnish hospitals between 2002 and 2014. Data were extracted from electronic patient records.

RESULTS

The follow-up was median 4.7 years (range 1 day to 12.3 years). Altogether 56 patients received PPI postoperatively, with the median 507 days from the operation (range 6 days to 10.0 years). The PPI indications were atrioventricular block (31 patients, 55%) and sick sinus syndrome (21 patients, 37.5%). For 4 patients, the PPI indication remained unknown. A competing risks regression analysis (Fine-Gray method), adjusted with age, sex, diabetes, coronary artery disease, preoperative atrial fibrillation (AF), left ventricular ejection fraction, New York Heart Association class, AF at discharge and urgency of operation, was used to assess risk factors for PPI. Only AF at discharge (subdistribution hazard ratio 4.34, 95% confidence interval 2.34-8.03) was a predictor for a PPI.

CONCLUSIONS

Though atrioventricular block is the major indication for PPI after surgical aortic valve replacement, >30% of PPIs are implanted due to sick sinus syndrome during both short-term follow-up and long-term follow-up. Postoperative AF versus sinus rhythm conveys >4-fold risk of PPI.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02626871.

Sutureless aortic valve prostheses

Conventional surgical aortic valve replacement (AVR) is the 'gold standard' for treatment of severe or symptomatic aortic valve stenosis. The increasing age of patients and increasing comorbidities has led to the development of procedures to minimise operative time and reduce risks of surgery. One method of reducing operative times is the use of sutureless aortic valves (SU-AVR). We examine the current literature surrounding the use of SU-AVR. Alternatives to AVR are SU-AVR, sometimes referred to as rapid deployment valves, or transcatheter aortic valve implantation (TAVI). TAVI has been demonstrated to be superior over medical therapy in patients deemed inoperable and non-inferior in high and intermediate-risk patients compared with surgical AVR. However, the lack of excision of the calcified aortic valve and annulus raises concerns regarding long-term durability and possibly thromboembolic complications. TAVI patients have increased rates of paravalvular leaks, major vascular complications and pacemaker implantation when compared with conventional AVR. SU-AVR minimises the need for suturing, leading to reduced operative times, while enabling complete removal of the calcified valve. The increase in use of SU-AVR has been mostly driven by minimally invasive surgery. Other indications include patients with a small and/or calcified aortic root, as well as patients requiring AVR and concomitant surgery. SU-AVR is associated with decreased operative times and possibly improved haemodynamics when compared with conventional AVR. However, this has to be weighed against the increased risk of paravalvular leak and pacemaker implantation when deciding which prosthesis to use for AVR.

Comparison of hemodynamic and clinical outcomes of transcatheter and sutureless aortic bioprostheses: how to make the right choice in intermediate risk patients

Current surgical treatment options for aortic valve stenosis (AS), as alternatives to that of conventional operation with a midline sternotomy, include sutureless valve replacement (SUAVR) and transcatheter valve implantation (TAVI). Patients with high surgical risk, or those who are judged to be inoperable, are typically good candidates for the TAVI procedure. The best treatment option in patients with an intermediate risk profile, however, the so called "grey zone", is still currently under debate. Sutureless aortic valve replacement has been recently presented as a valid alternative for patients with low- to intermediate-risk. Data available on prostheses' hemodynamic performance and patients' clinical outcomes play a crucial role in the process of device selection. Compared to TAVI, SUAVR provides lower rate of significant postoperative paravalvular leak (PVL), which has shown to be a predictor for mortality. On the contrary, transcatheter valves seem to perform better in terms of transvalvular mean and peak gradients. Therefore, SUAVR and TAVI are both reliable options in patients with severe aortic valve stenosis, as an alternative to conventional surgery, and the choice of the best device should be tailored to patient's anatomical and surgical characteristics.

Review of minimal access versus transcatheter aortic valve replacement for patients with severe aortic stenosis

Transcatheter aortic valve replacement (TAVR) and minimally invasive aortic valve replacement (miniAVR) have become alternatives to surgical aortic valve replacement via median sternotomy (SAVR) to treat severe aortic stenosis (AS). Despite increased interest and utilization, few studies have directly compared TAVR and miniAVR. A review of the current literature shows TAVR to be an indispensable tool for inoperable, high-risk, and perhaps intermediate-risk patients with severe AS. However, it is associated with a number of deleterious perioperative outcomes, such as valvular regurgitation and vascular complications. MiniAVR is associated with decreased intensive care unit (ICU) and hospital length of stay, a lower incidence of blood transfusions, decreased ventilation time, and improved cosmetic results. MiniAVR maintains potential advantages over SAVR, including the implantation of a durable prosthesis and low rates of perioperative myocardial infarction and paravalvular leak. It is associated with longer aortic cross clamp and cardiopulmonary bypass (CPB) times; however, the use of sutureless valve implants can circumvent this. Studies comparing TAVR and miniAVR demonstrate decreased postoperative mortality, valvular regurgitation, and incidence of stroke in the miniAVR cohorts. Few studies currently exist comparing TAVR and miniAVR, as it is hard to compare the typically low-risk miniAVR versus high-risk TAVR patient populations. It is clear that both strategies will be cornerstones in the modern AVR era, but the situations in which to apply each strategy have not yet been clearly delineated. This highlights the need for surgeons to adopt these minimally invasive techniques. We believe there is a compelling role for miniAVR in low- and intermediate-risk patients, but due to the paucity of data, neither TAVR nor miniAVR should be discounted before a randomized, risk-stratified trial is performed. More studies are needed to compare TAVR and miniAVR in low- and intermediate-risk patients.