Feasibility and safety of vitamin K antagonist monotherapy in atrial fibrillation patients undergoing transcatheter aortic valve implantation

Incidence, Current Guidelines and Management of Gastrointestinal Bleeding after Transcatheter Aortic Valve Replacement: A Systematic Review

BACKGROUND

There is a significant increase in morbidity and mortality in patients complicated by major bleeding following transcatheter aortic valve replacement (TAVR). It has become more challenging to manage such complications when the patient needs to be on anticoagulation or antiplatelet agent post-procedure to prevent thrombotic/embolic complications.

METHODS

We systematically reviewed all available randomized controlled trials and observational studies to identify incidence rates of gastrointestinal bleeding post-procedure. After performing a systematic search, a total of 8731 patients from 15 studies (5 RCTs and 10 non-RCTs) were included in this review.

RESULTS

The average rate of gastrointestinal bleeding during follow-up was 3.0% in randomized controlled trials and 1.9% among observational studies.

CONCLUSION

Gastrointestinal bleeding has been noted to be higher in the RCTs as compared to observational studies. This review expands knowledge of current guidelines and possible management of patients undergoing TAVR.

The search for optimal antithrombotic therapy in transcatheter aortic valve implantation: facts and uncertainties

Transcatheter aortic valve implantation (TAVI) is a minimally invasive procedure, which is used frequently in patients with symptomatic severe aortic valve stenosis. Most patients undergoing TAVI are over 80 years of age with a high bleeding as well as thrombotic risk. Despite the increasing safety of the procedure, thromboembolic events [stroke, (subclinical) valve thrombosis] remain prevalent. As a consequence, antithrombotic prophylaxis is routinely used and only recently new data on the efficacy and safety of antithrombotic drugs has become available. On the other hand, these antithrombotic drugs increase bleeding in a population with unique aortic stenosis-related bleeding characteristics (such as acquired von Willebrand factor defect and angiodysplasia). In this review, we discuss the impact of thromboembolic and bleeding events, the current optimal antithrombotic therapy based on registries and recent randomized controlled trials, as well as try to give a practical guide how to treat these high-risk patients. Finally, we discuss knowledge gaps and future research needed to fill these gaps.

Antithrombotic Therapy After Transcatheter Aortic Valve Replacement: An Overview

Transcatheter aortic valve replacement (TAVR) is an established procedure for the treatment of patients with severe aortic stenosis. The optimal antithrombotic regimen following TAVR, currently unknown and inconsistently applied, is impacted by thromboembolic risk, frailty, bleeding risk, and comorbidities. There is a quickly growing body of literature examining the complex issues underlying antithrombotic regimens post-TAVR. This review provides an overview of thromboembolic and bleeding events following TAVR, summarizes the evidence regarding optimal antiplatelet and anticoagulant use post-TAVR, and highlights current challenges and future directions. By understanding appropriate indications and outcomes associated with different antithrombotic regimens post-TAVR, morbidity and mortality can be minimized in a generally frail and elderly patient population.

Antithrombotic Therapy Following Transcatheter Aortic Valve Replacement

Due to a large technical improvement in the past decade, transcatheter aortic valve replacement (TAVR) has expanded to lower-surgical-risk patients with symptomatic and severe aortic stenosis. While mortality rates related to TAVR are decreasing, the prognosis of patients is still impacted by ischemic and bleeding complications, and defining the optimal antithrombotic regimen remains a priority. Recent randomized control trials reported lower bleeding rates with an equivalent risk in ischemic outcomes with single antiplatelet therapy (SAPT) when compared to dual antiplatelet therapy (DAPT) in patients without an underlying indication for anticoagulation. In patients requiring lifelong oral anticoagulation (OAC), the association of OAC plus antiplatelet therapy leads to a higher risk of bleeding events with no advantages on mortality or ischemic outcomes. Considering these data, guidelines have recently been updated and now recommend SAPT and OAC alone for TAVR patients without and with a long-term indication for anticoagulation. Whether a direct oral anticoagulant or vitamin K antagonist provides better outcomes in patients in need of anticoagulation remains uncertain, as recent trials showed a similar impact on ischemic and bleeding outcomes with apixaban but higher gastrointestinal bleeding with edoxaban. This review aims to summarize the most recently published data in the field, as well as describe unresolved issues.

Antithrombotic therapy after transcatheter aortic valve replacement: current perspective

PURPOSE OF REVIEW

Transcatheter aortic valve replacement (TAVR) has expanded as a treatment option for severe aortic stenosis throughout the surgical risk spectrum. Decreasing procedural risk and inclusion of lower risk population has shifted the focus to optimization of postprocedural management and balancing the thrombotic and bleeding complications. In this review, we outline various patient and procedure related factors affecting choice of antithrombotic therapy post TAVR and provide an update of recent development in this area.

RECENT FINDINGS

Multiple studies have confirmed the high incidence of both ischemic and bleeding complications in the early to midterm post-TAVR. In addition, new data has emerged for the role of high resolution computed tomography to detect decreased leaflet mobility and leaflet micro thrombi associated with implications for bioprosthetic valve dysfunction and cerebrovascular events post TAVR. Randomized clinical trials have reported increased bleeding with dual antiplatelet therapy (DAPT) and oral anticoagulation (OAC) plus antiplatelet therapy. These findings suggest that aspirin monotherapy or OAC monotherapy likely provides the appropriate balance for antithrombotic protection and risk of bleeding.

SUMMARY

Majority of patients undergoing TAVR have multiple comorbidities and are at increased risk of ischemic and bleeding complications. In the absence of robust clinical evidence, there is significant variability among guideline recommendations and antithrombotic therapy post TAVR across institutions. The available evidence confirms a high rate of bleeding with more potent and prolonged antithrombotic regimens without a documented benefit for clinical endpoints. The authors favor a conservative anti thrombotic approach and suggest monotherapy with aspirin or systemic anticoagulation based upon an individual's risk of thromboembolic complications. DAPT is reserved for patients with recent stenting and OAC plus aspirin is prescribed for patients with established CAD in the post TAVR setting.

Antithrombotic selection in patients undergoing transcatheter aortic valve replacement

PURPOSE

Clinical controversy regarding the most appropriate antithrombotic regimen after transcatheter aortic valve replacement remains. Current evidence, guidelines, and recommendations are discussed.

SUMMARY

Antithrombotic selection following transcatheter aortic valve replacement depends on a variety of patient-specific factors. For patients without a preexisting indication for anticoagulation, initial trials employed dual antiplatelet therapy as the postprocedural therapy of choice. Newer studies in this patient population, however, suggest single antiplatelet therapy reduces bleeding events without sacrificing ischemic protection. In patients with a preexisting indication for anticoagulation, warfarin plus single antiplatelet therapy, as opposed to triple antithrombotic therapy, offered similar ischemic protection while reducing clinically significant bleeding. Warfarin monotherapy was associated with a further reduction in bleeding events. One trial demonstrated the safety and efficacy of using apixaban in patients with concomitant atrial fibrillation; however, routine use of rivaroxaban increased adverse cardiac and bleeding events, leaving the utility of direct-acting oral anticoagulants in question.

CONCLUSION

Available evidence and current guidelines point to a lack of consensus regarding antithrombotic selection after transcatheter aortic valve replacement. Patient-specific factors and comorbidities must be considered when tailoring therapy, with an emphasis on balancing thrombotic and bleeding risks.

Temporal Trends and Outcomes of Percutaneous and Surgical Aortic Valve Replacement in Patients With Atrial Fibrillation

Objectives: The aim of this study was to evaluate the temporal trends of transcatheter aortic valve replacement (TAVR) in severe aortic stenosis (AS) patients with atrial fibrillation (AF) and to compare the in-hospital outcomes between TAVR and surgical aortic valve replacement (SAVR) in patients with AF.

Background: Data comparing TAVR to SAVR in severe AS patients with AF are lacking.

Methods: National inpatient sample database in the United States from 2012 to 2016 were queried to identify hospitalizations for severe aortic stenosis patients with AF who underwent isolated aortic valve replacement. A propensity score-matched analysis was used to compare in-hospital outcomes for TAVR vs. SAVR for AS patients with AF.

Results: The analysis included 278,455 hospitalizations, of which 124,910 (44.9%) were comorbid with AF. Before matching, TAVR had higher in-hospital mortality than SAVR (3.1 vs. 2.2%, p < 0.001); however, there was a declining trend during the study period (Ptrend < 0.001). After matching, TAVR and SAVR had similar in-hospital mortality (2.9 vs. 2.9%, p < 0.001) and stroke. TAVR was associated with lower rates of acute kidney injury, new dialysis, cardiac complications, acquired pneumonia, sepsis, mechanical ventilation, tracheostomy, non-routine discharge, and shorter length of stay; however, TAVR was associated with more pacemaker implantation and higher cost. Of the patients receiving TAVR, the presence of AF was associated with an increased rate of complications and increased medical resource usage compared to those without AF.

Conclusions: In-hospital mortality and stroke for TAVR and SAVR in AF, AS are similar; however, the in-hospital mortality in TAVR AF is declining and associated with more favorable in-hospital outcomes.

Optimal antithrombotic therapy after transcatheter aortic valve replacement in patients with atrial fibrillation

Atrial fibrillation (AF) is prevalent in patients with aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). Depending on the timing of AF detection, it is usually categorized as pre-existing AF or new-onset AF. Antiplatelet therapy, rather than a vitamin K antagonist, may be considered as the primary treatment for patients without an indication for oral anticoagulants who undergo TAVR. However, the optimal postprocedural antithrombotic regimen for patients with AF undergoing TAVR remains unknown. In this review, we briefly introduce the management strategies of antithrombotic therapy and list the evidence from related studies to elucidate the optimal antithrombotic management for patients with AF undergoing TAVR.

Comparing anticoagulation therapy alone versus anticoagulation plus single antiplatelet drug therapy after transcatheter aortic valve implantation in patients with an indication for anticoagulation: a systematic review and meta-analysis

PURPOSE

This meta-analysis compared the efficacy and safety of oral anticoagulation (OAC) therapy alone versus OAC plus single antiplatelet therapy (SAPT) in patients with an indication for chronic OAC (mostly due to atrial fibrillation) after transcatheter aortic valve implantation (TAVI).

METHODS

A systematic literature search was performed in the PubMed, Embase, and Cochrane Library databases to identify relevant studies. Data was extracted from the eligible studies and outcomes expressed as relative risks (RRs) with 95% confidence intervals (CIs).

RESULTS

Five studies comprising 1344 patients with an indication for chronic OAC and undergoing TAVI were included. Of the 1344 patients, 480 patients received OAC therapy alone and 864 patients received OAC plus SAPT. There were no significant differences between OAC alone versus OAC plus SAPT in all-cause mortality (RR = 1.05, 95% CI 0.84-1.30, p = 0.69) and ischemic stroke (RR = 0.95, 95% CI 0.95-1.61, p = 0.86). However, OAC alone was associated with significantly lower risks of all bleeding events (RR = 0.62, 95% CI 0.49-0.69, p < 0.0001) and major and/ life-threatening bleeding events (RR = 0.57, 95% CI 0.42-0.76, p = 0.0002) compared to OAC plus SAPT.

CONCLUSION

In patients with an indication for chronic anticoagulation, post-TAVI antithrombotic therapy with OAC alone compared to OAC plus SAPT may be not significantly different in reducing all-cause mortality and ischemic stroke, but has an important benefit in a significantly lower risk of all bleeding and major and/life-threatening bleeding events.

Anticoagulation With or Without Antiplatelet Therapy Following Transcatheter Aortic Valve Replacement for Patients With Atrial Fibrillation: A Meta-Analysis

BACKGROUND

Although current guidelines recommend oral anticoagulants (OAC) with or without antiplatelet therapy (APT) following transcatheter aortic valve replacement (TVAR) in patients with an indication for long-term anticoagulation therapy, the optimal antithrombotic strategy remains unknown in these population. Herein, we conducted a meta-analysis comparing the outcome of OAC alone versus OAC with APT following TAVR in patients with atrial fibrillation (AF).

METHODS

MEDLINE and EMBASE were searched through May 2020 to identify clinical trials that investigated OAC alone versus OAC with APT following TAVR in patients with AF. From each study, we extracted the hazard ratios (HRs) or risk ratios of major or life threatening bleeding, stroke, all-cause mortality and cardiovascular mortality.

RESULTS

1 randomized controlled trial and 3 observational studies were identified, which enrolled a total of 2032 patients with AF who underwent TAVR assigned to the OAC group (n = 722) or OAC with APT group (n = 1310). Pooled analyses demonstrated the rate of major or life threatening bleeding was significantly lower in the OAC group compared to the OAC with APT group (HR [95% Confidence Interval [CI] = 0.54 [0.38-0.77], P = .0006]). However, the rate of stroke was similar in both groups (HR [95% CI] = 1.22 [0.80-1.87], P = .36). All-cause and cardiovascular mortalities were also similar in both groups.

CONCLUSIONS

We observed that OAC with APT following TAVR in patients with AF increased the risk of bleeding compared to OAC alone without decreasing the risk of stroke.

Comparative efficacy and safety of antithrombotic therapy for transcatheter aortic valve replacement: a systematic review and network meta-analysis

OBJECTIVES

We sought to determine the optimal antithrombotic therapy after transcatheter aortic valve replacement.

METHODS

Related scientific databases were searched until December 2018. We conducted a pairwise and a network meta-analysis within a frequentist framework, measuring 30-day bleeding, stroke and all-cause mortality. The surface under the cumulative ranking (SUCRA) curve was estimated to rank the therapies. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was performed. The protocol was registered with PROSPERO (CRD42018111163).

RESULTS

Eight studies comprising 2173 patients were analysed. The risk of 30-day bleeding was higher for dual antiplatelet therapy (DAPT) than single antiplatelet therapy (SAPT) [odds ratio (OR) 1.90 (1.10-3.28); P = 0.02], whereas there was no difference in the risk of 30-day stroke [OR 1.27 (0.38-4.20); P = 0.69] and mortality [OR 1.46 (0.67-3.22); P = 0.34] between DAPT and SAPT. In the network meta-analysis, DAPT + oral anticoagulant (OAC) increased the risk of 30-day bleeding compared with SAPT [OR 6.21 (1.74-22.17); P = 0.005], DAPT [OR 3.27 (1.04-10.32); P = 0.043], SAPT + OAC [OR 4.87 (2.51-9.45); P < 0.001] and OAC [OR 14.4 (1.3-154.7); P = 0.028]. Additionally, patients receiving DAPT + OAC had the highest risks for 30-day bleeding (SUCRA 1.0%). OAC seemed to be superior to SAPT and DAPT in terms of 30-day bleeding (SUCRA OAC: 86.3%, SAPT: 72.3%, DAPT: 32.3%) and stroke (SUCRA 54.2%, 47.4%, 40.5%), but not mortality (SUCRA 69.6%, 74.1%, 43.4%).

CONCLUSIONS

There is a trend towards less bleeding with the application of SAPT, but no mortality benefit with the application of DAPT is shown. The comparison of SAPT, DAPT and OAC shows that OAC may improve the balance between stroke and bleeding, which can reduce the risk of mortality. In addition, the application of DAPT + OAC was ranked the worst amongst all treatment modalities and should be avoided due to an increased risk of bleeding.

CLINICAL TRIAL REGISTRATION NUMBER

PROSPERO (International Prospective Register of Systematic Reviews, CRD42018111163).

Anticoagulation with or without Clopidogrel after Transcatheter Aortic-Valve Implantation

BACKGROUND

The roles of anticoagulation alone or with an antiplatelet agent after transcatheter aortic-valve implantation (TAVI) have not been well studied.

METHODS

We performed a randomized trial of clopidogrel in patients undergoing TAVI who were receiving oral anticoagulation for appropriate indications. Patients were assigned before TAVI in a 1:1 ratio not to receive clopidogrel or to receive clopidogrel for 3 months. The two primary outcomes were all bleeding and non-procedure-related bleeding over a period of 12 months. Procedure-related bleeding was defined as Bleeding Academic Research Consortium type 4 severe bleeding, and therefore most bleeding at the puncture site was counted as non-procedure-related. The two secondary outcomes were a composite of death from cardiovascular causes, non-procedure-related bleeding, stroke, or myocardial infarction at 12 months (secondary composite 1) and a composite of death from cardiovascular causes, ischemic stroke, or myocardial infarction (secondary composite 2), both tested for noninferiority (noninferiority margin, 7.5 percentage points) and superiority.

RESULTS

Bleeding occurred in 34 of the 157 patients (21.7%) receiving oral anticoagulation alone and in 54 of the 156 (34.6%) receiving oral anticoagulation plus clopidogrel (risk ratio, 0.63; 95% confidence interval [CI], 0.43 to 0.90; P = 0.01); most bleeding events were at the TAVI access site. Non-procedure-related bleeding occurred in 34 patients (21.7%) and in 53 (34.0%), respectively (risk ratio, 0.64; 95% CI, 0.44 to 0.92; P = 0.02). Most bleeding occurred in the first month and was minor. A secondary composite 1 event occurred in 49 patients (31.2%) receiving oral anticoagulation alone and in 71 (45.5%) receiving oral anticoagulation plus clopidogrel (difference, -14.3 percentage points; 95% CI for noninferiority, -25.0 to -3.6; risk ratio, 0.69; 95% CI for superiority, 0.51 to 0.92). A secondary composite 2 event occurred in 21 patients (13.4%) and in 27 (17.3%), respectively (difference, -3.9 percentage points; 95% CI for noninferiority, -11.9 to 4.0; risk ratio, 0.77; 95% CI for superiority, 0.46 to 1.31).

CONCLUSIONS

In patients undergoing TAVI who were receiving oral anticoagulation, the incidence of serious bleeding over a period of 1 month or 1 year was lower with oral anticoagulation alone than with oral anticoagulation plus clopidogrel. (Funded by the Netherlands Organization for Health Research and Development; POPular TAVI EU Clinical Trials Register number, 2013-003125-28; ClinicalTrials.gov number, NCT02247128.).

Anticoagulation after Transcatheter Aortic Valve Implantation: Current Status

Transcatheter aortic valve implantation (TAVI) is the standard of care for symptomatic severe aortic stenosis. Antithrombotic therapy is required after TAVI to prevent thrombotic complications but it increases the risk of bleeding events. Current clinical guidelines are mostly driven by expert opinion and therefore yield low-grade recommendations. The optimal antithrombotic regimen following TAVI has yet to be determined and several randomised controlled trials assessing this issue are ongoing. The purpose of this article is to critically explore the impact of antithrombotic drugs, especially anticoagulants, on long-term clinical outcomes following successful TAVI.

Antithrombotic Therapy After Transcatheter Aortic Valve Implantation

The development of transcatheter aortic valve implantation has represented one of the greatest advances in the cardiology field in recent years and has changed clinical practice for patients with aortic stenosis. Despite the continuous improvement in operators’ experience and techniques, and the development of new generation devices, thromboembolic and bleeding complications after transcatheter aortic valve implantation remain frequent, and are a major concern due to their negative impact on prognosis in this vulnerable population. In addition, the optimal antithrombotic regimen in this scenario is not known, and current recommendations are mostly empirical and not evidence based. The present review aims to provide an overview of the current status of knowledge, including relevant on-going randomised trials, on antithrombotic treatment strategies after transcatheter aortic valve implantation.

Antithrombotic Therapy After Transcatheter Aortic Valve Replacement

The performance of transcatheter aortic valve replacement has expanded considerably during the past decade. Technological advances and refinement in implantation techniques have resulted in improved procedural outcomes, whereas indications are progressively extending toward lower-risk patients. Ischemic/embolic complications and major bleeding remain important and strongly correlate to mortality. In this regard, the optimal antithrombotic regimen after successful transcatheter aortic valve replacement remains unclear, in the absence of randomized trials. For patients without an indication for oral anticoagulation, empirical treatment with dual antiplatelet therapy (aspirin plus clopidogrel) for 3 to 6 months is currently recommended. However, dual antiplatelet therapy has been preliminarily associated with increased risk of bleeding compared with single antiplatelet therapy without significant ischemic benefit. Non-vitamin K oral anticoagulants and warfarin have also entered clinical investigation, to address the issue of preexisting or new-onset of atrial fibrillation and potentially attenuate subclinical leaflet thrombosis. Clinical trials are necessary to systematically address the risks and benefits of these approaches. In this review, we present the pathophysiological mechanisms of post-transcatheter aortic valve replacement complications and provide updated insights on the rationale behind the various antithrombotic regimens being currently evaluated in large randomized trials.

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.

[What antithrombotic treatment should we prescribe after transvalvular aortic valve implantation?]

The performance and indications of transvalvular aortic valve implantation or TAVI has considerably expanded and is now the first therapeutic line option in the management of severe aortic stenosis. The targeted population shares both high risk of ischemic complications, particularly stroke or subclinical leaflet thrombosis of the bioprothesis, as well as hemorrhagic complications, strongly correlated to death. Based on previous experience with intracoronary stents, a dual antiplatelet therapy has been recommended by experts' consensus. This paradigm is now challenged by the observed increased risk of hemorrhagic complications without a reduction of ischemic events. Moreover, the role of non-vitamin K oral anticoagulant in patients undergoing TAVI remains to be determined. Several large ongoing randomized controlled trials will likely change our practice within the next coming year.

Antithrombotic strategies after transcatheter aortic valve implantation: Insights from a network meta-analysis

OBJECTIVES

We aimed to investigate the efficacy and safety of different antithrombotic strategies in patients undergoing transcatheter aortic valve implantation (TAVI) using network meta-analyses.

BACKGROUND

Meta-analyses comparing single antiplatelet therapy (SAPT) vs. dual antiplatelet therapy (DAPT), ± oral anticoagulant (OAC) was conducted to determine the appropriate post TAVI antithrombotic regimen. However, there was limited direct comparisons across the different therapeutic strategies.

METHODS

MEDLINE and EMBASE were searched through December 2018 to investigate the efficacy and safety of different antithrombotic strategies (SAPT, DAPT, OAC, OAC + SAPT, and OAC + DAPT) in patients undergoing TAVI. The main outcome were all-cause mortality, major or life-threatening bleeding events, and stroke.

RESULTS

Our search identified 3 randomized controlled trials and 10 nonrandomized studies, a total of 20,548 patients who underwent TAVI. All OACs were vitamin K antagonists. There was no significant difference on mortality except that OAC + DAPT had significantly higher rates of mortality compared with others (p < .05, I² = 0%). SAPT had significantly lower rates of bleeding compared with DAPT, OAC+SAPT, and OAC+DAPT (hazard ratio [HR]: 0.59 [0.46-0.77], p < .001, HR: 0.58 [0.34-0.99], p = .045, HR: 0.41 [0.18-0.93], p = .033, respectively, I² = 0%). There was no significant difference on stroke among all antithrombotic strategies.

CONCLUSION

Patients who underwent TAVI had similar all-cause mortality rates among different antithrombotic strategies except OAC+DAPT. Patients on SAPT had significantly lower bleeding risk than those on DAPT, OAC + SAPT, and OAC + DAPT. Our results suggest SAPT is the preferred regimen when there is no indication for DAPT or OAC. When DAPT or OAC is indicated, DAPT + OAC should be avoided.

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.

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.

Antithrombotic therapy in patients undergoing transcatheter aortic valve implantation

This review provides a comprehensive overview of the available data on antithrombotic therapy after transcatheter aortic valve implantation (TAVI). In the absence of large randomised clinical trials, clinical practice is leaning towards evidence reported in other populations. Due to the greater risk of major bleeding associated with oral anticoagulation using a vitamin-K antagonist (VKA), antiplatelet therapy (APT) may be considered as the first-line treatment of patients undergoing TAVI. Overall, single rather than dual APT is preferred. However, dual APT should be considered in patients with a recent acute coronary syndrome (ie, within 6 months), complex coronary stenting, large aortic arch atheromas or previous non-cardioembolic stroke. Monotherapy with VKA should be considered if concomitant atrial fibrillation or any other indication for long-term oral anticoagulation is present. APT on top of VKA seems only reasonable in patients with recent acute coronary syndrome, extensive or recent coronary stenting or large aortic arch atheromas. A direct-acting oral anticoagulant may be considered if oral anticoagulation is indicated in the absence of contraindications. Initiation of VKA is indicated in clinical valve thrombosis, for example, with high transvalvular gradient, whereas the role of VKA in the case of subclinical leaflet thrombosis is currently uncertain.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.