Antithrombotic Therapy for Prevention of Cerebral Thromboembolic Events After Transcatheter Aortic Valve Replacement: Evolving Paradigms and Ongoing Directions.JACC Cardiovasc Interv. 2017;10:1366-1369. [PMID: 28527775 DOI: 10.1016/j.jcin.2017.05.005]

Aortic stenosis and Heyde’s syndrome: A comprehensive review

Heyde’s syndrome is an under reported systemic disease of gastrointestinal and cardiac manifestation in older adults. It is characterized by a triad of aortic stenosis, angiodysplasia with bleeding and acquired von Willebrand syndrome. It is characterized by proteolysis of high molecular weight multimers of von Willebrand Factor and loss of platelet mediated homeostasis. Heyde’s syndrome is a treatable condition in most cases, especially in the current era of evolution in interventional cardiology and gastroenterology. There are currently no established guidelines in the management of this condition due to paucity of high quality studies, which warrant future trials. High index of suspicion and increasing the awareness of the syndrome among the general practitioners and sub-specialists will improve the diagnostic potential of Heyde’s syndrome. Future studies may change the management aspect of Heyde's syndrome and pave a path for drawing specific guidelines and algorithms. The aim of our review article is to summarize the basic pathophysiology, diagnostics and management of Heyde’s syndrome with a special attention to Transcatheter aortic valve replacement.

Risks and benefits of concurrent treatment with antiplatelet and anticoagulation therapy in post-op bioprosthetic aortic valve replacement patients

BACKGROUND AND AIM

Among patients receiving surgical bioprosthetic aortic valve replacement (bAVR), there is an elevated risk of thromboembolic events postoperatively. However, the risks and benefits of varying anticoagulation strategies remain controversial. The aim of this study is to compare the risks and benefits of aspirin monotherapy to aspirin plus warfarin ("concurrent therapy") in patients receiving bAVR.

METHODS

A retrospective cohort study was conducted using patients' data from Kaiser Permanente Northern California, including those who underwent bAVR with or without coronary artery bypass grafting between 2009 and 2018. Patients were identified as having been discharged with aspirin only or concurrent therapy. The outcomes were mortality, thromboembolic events, and clinically relevant bleeding during a 6-month follow-up. The event rates were compared using the Kaplan-Meier method. Multivariable survival analysis, incorporating propensity scores, was used to estimate adjusted hazard ratios (aHRs) for each outcome.

RESULTS

The cohort consisted of 3047 patients. Approximately 58% of patients received aspirin only and 42% received concurrent therapy. Patients who received concurrent therapy were more likely to be older, have hypertension, previous stroke, and longer hospital stays. After adjustment using multivariable analysis, concurrent therapy was associated with a higher risk of clinically relevant bleeding (aHR, 2.33; 95% confidence interval, 1.67-3.25). There was no significant difference in the risk of thromboembolic events or mortality between the two groups.

CONCLUSION

Patients who underwent bAVR and were discharged on concurrent therapy compared to aspirin only had a significantly increased risk of bleeding without a significant difference in thromboembolic events.

Rationale and design of the ADAPT-TAVR trial: a randomised comparison of edoxaban and dual antiplatelet therapy for prevention of leaflet thrombosis and cerebral embolisation after transcatheter aortic valve replacement

INTRODUCTION

Optimal antithrombotic strategy following transcatheter aortic valve replacement (TAVR) is still unknown. We hypothesised that the direct factor Xa inhibitor edoxaban can potentially prevent subclinical leaflet thrombosis and cerebral embolisation compared with conventional dual antiplatelet therapy (DAPT) in patients undergoing TAVR.

METHODS AND ANALYSIS

The ADAPT-TAVR trial is an international, multicentre, randomised, open-label, superiority trial comparing edoxaban-based strategy and DAPT strategy in patients without an indication for oral anticoagulation who underwent successful TAVR. A total of 220 patients are randomised (1:1 ratio), 1-7 days after successful TAVR, to receive either edoxaban (60 mg daily or 30 mg daily if patients had dose-reduction criteria) or DAPT using aspirin (100 mg daily) plus clopidogrel (75 mg daily) for 6 months. The primary endpoint was an incidence of leaflet thrombosis on four-dimensional, volume-rendered cardiac CT imaging at 6 months post-TAVR. The key secondary endpoints were the number of new lesions and new lesion volume on brain diffusion-weighted MRI and the changes in neurological and neurocognitive function assessment between immediate post-TAVR and 6 months of study drug administration. Detailed clinical information on thromboembolic and bleeding events were also assessed.

ETHICS AND DISSEMINATION

Ethic approval has been obtained from the Ethics Committee/Institutional Review Board of Asan Medical Center (approval number: 2017-1317) and this trial is also approved by National Institute of Food and Drug Safety Evaluation of Republic of Korea (approval number: 31511). Results of this study will be disseminated in scientific publication in reputed journals.

TRIAL REGISTRATION NUMBER

NCT03284827.

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 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.

Dual-pathway inhibition for secondary and tertiary antithrombotic prevention in cardiovascular disease

Advances in antiplatelet therapies for patients with cardiovascular disease have improved patient outcomes over time, but the challenge of balancing the risks of ischaemia and bleeding remains substantial. Moreover, many patients with cardiovascular disease have a residual risk of ischaemic events despite receiving antiplatelet therapy. Therefore, novel strategies are needed to prevent clinical events through mechanisms beyond platelet inhibition and with an acceptable associated risk of bleeding. The advent of non-vitamin K antagonist oral anticoagulants, which attenuate fibrin formation by selective inhibition of factor Xa or thrombin, has renewed the interest in dual-pathway inhibition strategies that combine an antiplatelet agent with an anticoagulant drug. In this Review, we highlight the emerging pharmacological rationale and clinical development of dual-pathway inhibition strategies for the prevention of atherothrombotic events in patients with different manifestations of cardiovascular disease, such as coronary artery disease, cerebrovascular disease and peripheral artery disease.

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 Management of Patients With Prosthetic Heart Valves

Valvular heart disease is a major public health issue. The prevalence of valvular heart disease is expected to increase due to an aging population. Valve dysfunction manifests as valve stenosis, regurgitation, or both due to various etiologies. Valve repair and replacement are the main treatment options for severe valve dysfunction. Valve replacement is achieved by using either a mechanical or a bioprosthetic valve. Mechanical valves are more durable but require lifelong anticoagulation with associated complications. Bioprosthetic valves usually require anticoagulation only transiently after implantation but are less durable and degenerate more rapidly. In this article, we discuss antithrombotic regimens in persons after valve operations. We discuss general issues and antithrombotic recommendations for patients undergoing surgical bioprosthetic valve replacement, mechanical valve replacement (including different regimens for different positions and types of mechanical valves), mitral valve repair, and transcatheter aortic valve replacement. In addition, we discuss the antithrombotic management of patients in special circumstances, including patients with mechanical valves who have recurrent bleeding or thrombotic events, patients with mechanical valves undergoing surgery, and pregnant women with mechanical valves.

Transcatheter aortic valve implantation: Update in 2018

During the last 15 years, transcatheter aortic valve implantation (TAVI) has gained wide acceptance with good reproducible clinical and safety outcomes. Today, TAVI has not only overtaken conventional surgery as the standard of care for the treatment of patients with symptomatic aortic stenosis at high surgical risk, but can also be considered in selected intermediate-risk patients. This follows technological improvements, better patient assessment and increased operator experience leading to a significant reduction in most procedure-related complications and long-term mortality. In this review, we provide internists, on the one hand with current data in the TAVI field including clinical outcomes from the most recent, major trials and on the other hand, highlight the remaining pitfalls of this treatment and the gaps in evidence that need to be addressed in order to further improve clinical practice and expand its indication.