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.

Management of atrial fibrillation after transcatheter aortic valve replacement: Challenges and therapeutic considerations

Atrial Fibrillation (AF) is very common among patients with severe aortic stenosis. Moreover, new onset AF (NOAF) is a frequent finding after Transcatheter Aortic Valve Replacement (TAVR). There is a significant impact of AF on outcomes in patients undergoing TAVR including mortality, thrombo-embolic and bleeding events. There is lack of clear evidence about the optimal management of AF in TAVR patients. This review aims to summarize the epidemiology, predictors, prognosis, therapeutic considerations and challenges in the management of AF in patients undergoing TAVR.

Antithrombotic Therapy in Transcatheter Aortic Valve Replacement

Transcatheter aortic valve replacement (TAVR) has recently emerged as an effective alternative to medical treatment or surgical aortic valve replacement in all symptomatic patients with severe aortic stenosis and high or prohibitive risk and in intermediate risk when transfemoral access is feasible. Patients undergoing TAVR are often at high risk for either bleeding or cerebrovascular complications, or both, so adjuvant antithrombotic therapies are commonly used before, during and after the procedure. Today, there is no clear evidence on the best antithrombotic regimen in this context. In this review, we will try to go through the mechanisms involved in bleeding and embolic complications and we will discuss the current points of antithrombotic treatment in patients during and after TAVR, with or without oral anticoagulation (OAC) indication.

Thrombo-embolic prevention after transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) has emerged as a valuable treatment alternative to surgical aortic valve replacement among patients with symptomatic aortic stenosis at increased surgical risk. The rapid technological evolution from early to current-generation TAVI systems with low-profile delivery catheters, bioprosthetic valves with proven midterm durability, and improved positioning and retrieval features have made important contributions to the widespread clinical use of this minimal invasive therapy. Although peri-procedural and long-term thrombotic and bleeding events after TAVI remain a relevant concern, the optimal antithrombotic strategy and duration to mitigate these risks remain unclear. This review provides an overview of recent insights in this field, and highlights current and future antithrombotic trials focusing on optimizing outcomes in patients undergoing TAVI.

Atrial fibrillation in patients undergoing transcatheter aortic valve implantation: epidemiology, timing, predictors, and outcome

Atrial fibrillation (AF) is a common arrhythmia in patients with aortic stenosis. When these patients are treated medically or by surgical aortic valve replacement, AF is associated with increased risk of adverse events including death. Growing evidence suggests a significant impact of AF on outcomes also in patients with aortic valve stenosis undergoing transcatheter aortic valve implantation (TAVI). Conversely, limited evidence is available regarding the optimal management of this condition. This review aims to summarize prevalence, pathophysiology, prognosis, and treatment of AF in patients undergoing TAVI.

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

AIMS

We aimed to assess the efficacy and safety of vitamin K antagonist (VKA) monotherapy in atrial fibrillation (AF) patients undergoing transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

In 735 TAVIs since 2008 we identified 167 patients suffering from concomitant AF who received either VKA monotherapy (n=77), VKA plus single antiplatelet therapy (SAPT, n=41) or a triple anticoagulation regimen (n=49). Thromboembolic as well as bleeding complications were analysed for six months after TAVI. Only one minor bleeding and no thromboembolic events occurred after VKA therapy had been initiated post TAVI. Compared to patients being treated with additional either single or dual antiplatelet therapy, the incidence of major/life-threatening bleeding complications was significantly lower in the VKA mono group (0/77 [VKA mono] vs. 3/41 [VKA+SAPT; p=0.04] vs. 4/49 [triple anticoagulation; p=0.02]). Analysis of a combined endpoint of post-procedural death, stroke, embolism and major bleeding revealed a significant superiority of VKA monotherapy compared to VKA plus SAPT or DAPT, respectively (5/77 vs. 9/41 [p=0.02] vs. 14/49 [p=0.002]).

CONCLUSIONS

VKA therapy without additional antiplatelet treatment is effective and safe in AF patients undergoing TAVI.

LAA occluder device for stroke prevention: Data on WATCHMAN and other LAA occluders

NOAC therapy has become the standard for stroke prevention in patients with atrial fibrillation. Yet some patients suffer extracranial bleeding events or have other reasons to seek non-pharmacologic stroke protection. LAA occlusion with the WATCHMAN device has been proven safe and effective for such patients and is now recommended in current guidelines for this patient group; other devices also seek approval.

Transcatheter Aortic Valve Replacement 2016: A Modern-Day "Through the Looking-Glass" Adventure

Transcatheter aortic valve replacement (TAVR) has become a safe and effective therapy for patients with severe aortic stenosis (AS). In recent trials, the hemodynamic performance and clinical outcomes of the latest generation of TAVR devices demonstrated at least parity with surgical outcomes in patients of similar risk. Many initial obstacles with TAVR have largely been overcome, including frequent access site complications and concerns about strokes and paravalvular leaks. Using a multidisciplinary heart team approach, patient selection, procedural planning, and device implantation have been refined and optimized such that clinical outcomes are generally predictable and reproducible. Future research will focus on the durability of TAVR devices, further enhancements in clinical outcomes, and adjunctive therapies. On the basis of initial results from ongoing clinical trials, the indication for TAVR will likely expand to lower-risk patients. This review provides an overview of recent progress in this field, and highlights future opportunities and directions.

Transcatheter Closure of Atrial Septal Defect with Attenuated Anterior Rim after Transcatheter Aortic Valve Implantation: Can It Be Carried out as a Single Procedure?

Transcatheter aortic valve replacement (TAVR) has emerged as a highly effective minimally invasive treatment for symptomatically critical aortic stenosis (AS) in patients at high or prohibitive surgical risk. We report a case of staged transcatheter management of critical AS combined with an atrial septal defect (ASD) with attenuated anterior superior rim. The clinical result of this case suggests that both procedures can be safely performed simultaneously. Therefore, combined transcatheter treatment may appear as a possible strategy in patients with concomitant cardiac conditions.

Transcatheter Aortic Valve Replacement and Left Atrial Appendage Occlusion - A Stitch in Time?

Many patients have now been able to receive transcatheter aortic valve replacement (TAVR) therapy for severe aortic stenosis. These patients have atrial fibrillation and are placed on warfarin for stroke prophylaxis. The opportunity for treatment with left atrial appendage occlusion (LAAO) in place of warfarin for this population exists, especially for those with increased bleeding risk. This paper discusses the prevalence and aetiology of stroke in patients presenting for TAVR (with a focus on the risk from chronic and acute atrial fibrillation) and also the benefit of LAAO closure in this population.