Variation in post-TAVR antiplatelet therapy utilization and associated outcomes: Insights from the STS/ACC TVT Registry

Prospective study on the impact of different anti-thrombotic therapies on subclinical leaflet thickening and its temporal dynamics in transcatheter aortic valves - The NOTION-4 trial: Anti-thrombotic therapy and TAV-HALT

BACKGROUND

Transcatheter aortic valve replacement (TAVR) has become the standard-of-care treatment for a majority of patients with severe, symptomatic aortic stenosis. The post-procedural anti-thrombotic therapeutic management is still a topic of debate and could affect the incidence of HALT, a phenomenon which can be assessed by four-dimensional computed tomography (4DCT).

TRIAL DESIGN

The NOTION-4 trial is a randomized controlled trial comprising TAVR patients with no indication for oral anticoagulant (OAC) therapy, comparing lifelong single anti-platelet therapy (standard arm) versus early 3-month direct oral anticoagulant (DOAC) therapy followed by single anti-plateletet therapy (experimental arm). The incidence of HALT and clinical endpoints will be evaluated in both groups at 3 months, 1 year and 5 years after randomization. The primary endpoint is the number of patients with at least one bioprosthetic aortic valve leaflet with HALT as assessed by cardiac 4DCT imaging at 1 year. The trial is powered for superiority testing and started enrollment in 2021. In total, 324 patients will be included. The last patient is expected to be enrolled by the end of 2024 and the primary endpoint is to be presented in 2026.

CONCLUSION AND PERSPECTIVE

The NOTION-4 trial aims to study whether an early 3-month DOAC therapy after TAVR can result in a sustained lower incidence of HALT in transcatheter aortic valves. This trial holds the potential to give valuable insights into whether early OAC therapy should be integrated in future guidelines for post-TAVR anti-thrombotic therapeutic management.

TRIAL REGISTRATION

NOTION-4, ClinicalTrials.gov ID NCT06449469, https://clinicaltrials.gov/study/NCT06449469.

An investigator-sponsored pragmatic randomized controlled trial of AntiCoagulation vs AcetylSalicylic Acid after Transcatheter Aortic Valve Implantation: Rationale and design of ACASA-TAVI

BACKGROUND

The optimal antithrombotic therapy after transcatheter aortic valve implantation (TAVI) is unknown. Bioprosthetic valve dysfunction (BVD) is associated with adverse outcomes and may be prevented by anticoagulation therapy. A dedicated randomized trial comparing monotherapy NOAC to single antiplatelet therapy has not been performed previously. We hypothesize that therapy with any anti-factor Xa NOAC will reduce BVD compared to antiplatelet therapy, without compromising safety.

METHODS

ACASA-TAVI is a multicenter, prospective, randomized, open-label, blinded endpoint, all-comers trial comparing a monotherapy anti-factor Xa NOAC strategy (intervention arm) with a single antiplatelet therapy strategy (control arm) after successful TAVI. Three-hundred and sixty patients without indication for oral anticoagulation will be randomized in a 1:1 ratio to either apixaban 5 mg twice per day, edoxaban 60 mg daily, or rivaroxaban 20 mg daily for 12 months followed by acetylsalicylic acid 75 mg daily indefinitely, or to acetylsalicylic acid 75 mg daily indefinitely. The 2 co-primary outcomes are (1) incidence of Hypo-Attenuated Leaflet Thickening (HALT) on 4-dimensional cardiac CT at 12 months, and (2) a Safety Composite of VARC-3 bleeding events, thromboembolic events (myocardial infarction and stroke), and death from any cause, at 12 months.

RESULTS

The first 100 patients had a mean age of 74 ± 3.6 years, 33% were female, the average body-mass index was 27.9 ± 4.4 kg/m2, and 15% were smokers. A balloon-expanded valve was used in 82% and a self-expandable valve in 18%.

CONCLUSIONS

The trial is planned, initiated, funded, and conducted without industry involvement.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier NCT05035277.

Aspirin Versus Warfarin after Transcatheter Aortic Valve Replacement in Low-Risk Patients: 2-Year Follow-Up

Subclinical leaflet thrombosis occurs with transcatheter heart valves (THVs) and could be associated with structural valve deterioration. The current guidelines recommend the use of antiplatelet agents after transcatheter aortic valve replacement (TAVR) but not the routine use of oral anticoagulation. Our study examines the effects of short-term warfarin therapy on THV hemodynamics at 24 months after TAVR in low-risk patients. Low-risk patients who underwent TAVR were randomly allocated 1:1 to receive low-dose aspirin (n = 50) or low-dose aspirin plus warfarin (n = 44). After 30 days of treatment, ongoing medication regimens, including anticoagulation, were at the physicians' discretion. Follow-up after a period of 24 months was available for clinical and echocardiographic outcomes. At the 24-month mark, follow-up echocardiography of the randomly allocated patients revealed just 1 additional case of new structural valve deterioration in the aspirin group (compared with the occurrence within 30 days), based on the Valve Academic Research Consortium 3 definitions. There were also no differences in mean pressure gradients (11.5 ± 0.5 mm Hg vs 11.05 ± 4.0 mm Hg, p = 0.6) or peak velocity (2.2 ± 0.5 m/s vs 2.1 ± 0.4 m/s, p = 0.7) between the groups. A composite end point (mortality, stroke, and myocardial infarction) did not show any difference between the groups at long-term follow-up (p = 0.07). In conclusion, in low-risk patients who underwent TAVR, short-term anticoagulation with warfarin did not impact clinical outcomes or THV hemodynamics by echocardiography at 24 months.

Medium-Term Outcomes of the Different Antithrombotic Regimens After Transcatheter Aortic Valve Implantation

Bioprosthetic valve thrombosis is associated with accelerated bioprosthesis degeneration and valve re-replacement. Whether 3-month warfarin use after transcatheter aortic valve implantation (TAVI) protects against such consequences is unknown. We aimed to investigate if 3-month warfarin treatment after TAVI is associated with better outcomes than dual antiplatelet therapy (DAPT) and single antiplatelet therapy (SAPT) at medium-term follow-up. Adults who underwent TAVI were identified retrospectively (n = 1,501) and classified into warfarin, DAPT, and SAPT groups based on antithrombotic regimen received. Patients with atrial fibrillation were excluded. Outcomes and valve hemodynamics were compared between the groups. Annualized change from baseline in mean gradients and effective orifice area at last follow-up echocardiography was calculated. Overall, 844 patients were included (mean age: 80 ± 9 years, 43% women; 633 receiving warfarin, 164 DAPT, and 47 SAPT). Median time to follow-up was 2.5 (interquartile range 1.2 to 3.9) years. There were no differences in the adjusted outcome end points of ischemic stroke, death, valve re-replacement/intervention, structural valve degeneration, or their composite end point at follow-up. Annualized change in aortic valve area was significantly higher in DAPT (-0.11 [0.19] cm²/year) than warfarin (-0.06 [0.25] cm²/y, p = 0.03), but annualized change in mean gradients was not different (p >0.05). In conclusion, antithrombotic regimen, including warfarin, after TAVI was associated with marginally lower decrease in aortic valve area but no difference in medium-term clinical outcomes compared with DAPT and SAPT.

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.

Post-Discharge Antithrombotic Therapy Following Transcatheter Aortic Valve Implantation in Australian Patients

BACKGROUND

Guidelines recommend antithrombotic therapy for patients following transcatheter aortic valve implantation (TAVI) to reduce the risk of ischaemic events and bioprosthetic valve thrombosis.

OBJECTIVE

To describe antithrombotic dispensing within 30 days of discharge for Australian patients receiving TAVI.

METHODS

We performed a state-wide retrospective cohort study using linked hospital and medicines dispensing data from January 2013 to December 2018 for all patients receiving TAVI in New South Wales, Australia. We identified patients dispensed oral anticoagulants (vitamin K antagonists [warfarin], direct oral anticoagulants [DOACs]) or clopidogrel within 30 days of discharge. We examined demographic and clinical predictors of antithrombotic dispensing.

RESULTS

Our cohort comprised 1,217 patients who underwent TAVI; median age was 84 years and 707 (58.1%) were male. Of these, 808 patients (66.4%) had an antithrombotic dispensed within 30 days of hospital discharge. One-third (33.7%) of these patients were dispensed an anticoagulant (16.1% warfarin; 17.6% DOACs) and two-thirds (66.3%) were dispensed clopidogrel. Patients undergoing TAVI were more likely to be dispensed an antithrombotic medicine within 30-days of hospital discharge if they had been dispensed antithrombotic medicines (RR 1.07; 95% CI 1.03-1.11) or angiotensin-converting-enzyme inhibitors/angiotensin II receptor blockers (RR 1.04; 95% CI 1.00-1.07) in the 6 months prior to admission. Patients with a history of haemorrhage were less likely to be dispensed an antithrombotic medicine within 30 days of hospital discharge (RR 0.93; 95% CI 0.89-0.98).

CONCLUSIONS

We observed gaps in best evidence pharmacotherapy for patients post-TAVI, with almost one third of patients not receiving antithrombotic medicines post-discharge. Further research is needed to quantify the impact of emerging clinical guidelines recommending single antiplatelet therapy, on adherence to best-practice care.

Real-World Anticoagulatory Treatment After Transcatheter Aortic Valve Replacement: A Retrospective, Observational Study on 4,800 Patients

Background: Transcatheter aortic valve replacement (TAVR) has developed to the therapy of choice for patients with symptomatic severe aortic stenosis who are unsuitable for surgical aortic valve replacement and elderly patients with intermediate or high operative risk. However, the optimal anticoagulant therapy post-TAVR still remains a matter of debate.

Aims: This study sought to investigate current anticoagulant treatment patterns and clinical outcome in patients undergoing TAVR.

Methods: In a retrospective study based on anonymized health claims data of approximately seven million Germans with statutory health insurance (InGef database), anticoagulant treatment regimens were assessed using any drug prescription post discharge within the first 90 days after TAVR procedure. Clinical events between 30 days and 6 months were examined by treatment regime.

Results: The study population comprised 4,812 patients with TAVR between 2014 and 2018: 29.4% received antiplatelet monotherapy, 17.8% dual antiplatelet therapy, 17.4% oral anticoagulation (OAC) plus antiplatelet therapy, 12.9% OAC monotherapy, 2.2% triple therapy and 19.2% did not receive any anticoagulatory drugs. Sixty-four percentage of patients with OAC received direct oral anticoagulants (DOAC). Hence, 68% of all patients were treated non-adherent to current guidelines. Forty percentage of patients with OAC prior to TAVR did not have any OAC after TAVR. The adjusted risk of all-cause mortality was significantly increased in patients with OAC (HR 1.40, 95% CI 1.03–1.90, p = 0.03) and no anticoagulatory treatment (HR 3.95, 95% CI 2.95–5.27, p < 0.0001) when compared to antiplatelet monotherapy.

Conclusions: This large real-world data analysis demonstrates substantial deviations from guideline recommendations and treatment after TAVR. Considering relevant differences in clinical outcome across treatment groups, major effort is warranted to examine underlying causes and improve guideline adherence.

Acute Type A Aortic Dissection Confounded by Aberrant Symptoms

Acute aortic dissection (AAD) is a cardiovascular emergency that requires emergent surgical, endovascular, or medical intervention depending on the portion of the aorta implicated, as dictated by the Stanford classification, and the extent of aortic involvement. Acute chest pain radiating to the back is typically seen in AAD and may be associated with radial pulse deficits. A high index of suspicion is required to diagnose and initiate management of this emergency as early as possible. This is a report of an atypical presentation of an extensive aortic dissection identified in a young man without most of the typical risk factors, but which was promptly diagnosed and treated.

Comparing Single- and Dual Antiplatelet Therapies Following Transcatheter Aortic Valve Implantation

BACKGROUND

Transcatheter aortic valve implantation has been an established treatment in patients with symptomatic severe aortic stenosis. However, the postoperative antiplatelet regimen after transcatheter aortic valve implantation was not established certainly. The aim of this meta-analysis is to compare the safety and efficacy of single- (SAPT) and dual-antiplatelet therapies (DAPT) in patients undergoing transcatheter aortic valve implantation.

METHODS

Eligible randomized controlled trials and cohort studies published before February 2021 were retrieved from PubMed, Embase, and the Cochrane Library. We calculated odds ratios with 95% confidence intervals.

RESULTS

Nine articles, involving 19,277 patients, met the selection criteria. In the short-term outcome, compared with SAPT, DAPT was associated with a significantly higher rate of bleeding (odds ratios, 95% confidence intervals: 3.00, 1.67-5.38) and showed no significant differences in thrombotic events (odds ratios, 95% confidence intervals: 1.25, 0.74-2.11) and all-cause mortality (odds ratios, 95% confidence intervals: 0.84; 0.42-1.69). In the long-term outcome, DAPT was associated with a significantly higher bleeding rate (odds ratios, 95% confidence intervals: 1.85, 1.24-2.78) and showed no differences in thrombotic events (odds ratios, 95% confidence intervals: 1.13, 0.86-1.48) and all-cause mortality (odds ratios, 95% confidence intervals: 1.12, 0.95-1.32). Our trial sequential analysis confirmed DAPT didn't confer any benefit for reducing all-cause mortality and thrombotic events, and carried a higher risk of bleeding than SAPT.

CONCLUSIONS

SAPT should be a sufficient antiplatelet strategy in post- transcatheter aortic valve implantation patients without indications for oral anticoagulation medication, especially in the long-term follow-up period.

Dual Antiplatelet Therapy vs. Single Antiplatelet Therapy After Transcatheter Aortic Valve Replacement: An Updated Systematic Review and Meta-Analysis

Background: Although mainstream guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and clopidogrel in patients following transcatheter aortic valve replacement (TAVR), it is not evidence-based. We aim to investigate the safety and efficacy of DAPT vs. single antiplatelet therapy (SAPT) after TAVR, and review updated evidence. Methods: We systematically searched PubMed, Embase, and Cochrane for studies comparing DAPT to SAPT after TAVR from inception to November 30, 2020. The primary outcome was major adverse cardiac and cerebrovascular events, including all-cause mortality, cardiovascular death, myocardial infarction (MI), stroke, and major or life-threatening bleeding (LTB). Subgroup analysis was performed according to study type (randomized control trials vs. observational studies) using a fixed-effects model. The quality of evidence was assessed by two scoring systems and GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Results: Twelve studies of 20,766 patients were included in our meta-analysis. Compared with SAPT, DAPT was associated with an increased risk for combined life threatening and major bleeding [OR 1.73 (1.19-2.51), p = 0.004] after TAVR. Such a difference was largely driven by major bleeding [OR 2.29 (1.68-3.11), p < 0.001]. There were no significant differences on major adverse cardiovascular events (MACE) [OR 1.19 (0.99-1.44), p = 0.07], cardiovascular mortality [OR 1.46 (0.93-2.30), p = 0.10], and stroke [OR 0.97 (0.80-1.16), p = 0.71]. Conclusions: Compared with SAPT, post-TAVR DAPT was associated with increased risks of major or life-threatening bleeding without additional benefits of reducing thrombotic events. Future guidelines for post-TAVR antiplatelet strategy are expected to be updated as new high-quality evidence emerges. Systematic Review Registration: PROSPERO, Identifier: CRD42021230075.

Antiplatelet therapy after transcatheter aortic valve implantation: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to compare antithrombotic regimens after transcatheter aortic valve implantation (TAVI) in patients without an indication for long-term anticoagulation. TAVI is a safe and effective approach for patients with symptomatic severe aortic stenosis and an intermediate-to-high surgical risk. Nevertheless, the antithrombotic regimen after procedure remains controversial.

METHODS

We systematically searched PubMed, Embase and Cochrane databases for interventional studies comparing single antiplatelet therapy with double antiplatelet therapy after TAVI. A meta-analysis was carried out to compare thrombotic and bleeding events between both strategies.

RESULTS

Four randomized clinical trials were included comprising a total of 1085 patients. Our meta-analysis revealed a higher odds ratio (OR) of major bleeding events (pooled OR 2.45, 95% confidence interval (CI) 1.29-4.67; P < 0.01; I2 = 0%) and minor bleeding (pooled OR 1.73, 95% CI 1.12-2.66; P = 0.01; I2 = 0%) for the double antiplatelet therapy group compared with the single antiplatelet therapy group. There was no difference between groups in the risk of stroke (pooled OR 1.04, 95% CI 0.58-1.86; P = 0.91; I2 = 0%), myocardial infarction (pooled OR 2.10, 95% CI 0.75-5.84; P = 0.16, I2 = 0%) and all-cause mortality (pooled OR 1.07, 95% CI 0.63-1.86; P = 0.08; I2 = 0%) after TAVI.

CONCLUSIONS

Our pooled analysis suggests that for patients who underwent TAVI, double antiplatelet therapy compared with single antiplatelet therapy alone increased the risk of bleeding without reducing mortality and ischaemic events.

Usefulness of Antiplatelet Therapy After Transcatheter Aortic Valve Implantation

The rationale for dual antiplatelet therapy (DAPT) after transcatheter aortic valve implantation (TAVI) is to facilitate endothelialization of metallic struts of the transcatheter heart valve and to prevent thrombosis that could lead to thromboembolic events. Based on expert consensus, current societal guidelines recommend DAPT for 1 to 6 months after TAVI with weak evidence. Although the pivotal TAVI trials mandated this regimen, the evidence for the efficacy of DAPT to prevent transcatheter heart valve thrombosis is limited to 3 small trials and a handful of observational studies. Multiple coronary trials have demonstrated that DAPT is associated with increased bleeding in comparison with single antiplatelet therapy, especially in elderly patients. TAVI patients are predominantly elderly and frequently have risk factors that predispose them to bleeding. Herein, we summarize the evidence for antiplatelet therapy after TAVI and explore the theoretical benefit of DAPT to prevent thromboembolic events versus the risk of increased bleeding.

Safety and Efficacy of Different Antithrombotic Strategies after Transcatheter Aortic Valve Implantation: A Network Meta-Analysis

BACKGROUND

 The optimal pharmacological therapy after transcatheter aortic valve implantation (TAVI) remains uncertain. We compared efficacy and safety of various antiplatelet and anticoagulant approaches after TAVI by a network meta-analysis.

METHODS

 A total of 14 studies (both observational and randomized) were considered, with 24,119 patients included. Primary safety endpoint was the incidence of any bleeding complications during follow-up. Secondary safety endpoint was major bleeding. Efficacy endpoints were stroke, myocardial infarction, and cardiovascular mortality. A frequentist network meta-analysis was conducted with a random-effects model. The following strategies were compared: dual antiplatelet therapy (DAPT), single antiplatelet therapy (SAPT), oral anticoagulation (OAC), and OAC + SAPT. The mean follow-up was 15 months.

RESULTS

 In comparison to DAPT, SAPT was associated with a 44% risk reduction of any bleeding (odds ratio [OR]: 0.56 [95% confidence interval, CI: 0.39-0.80]). SAPT was ranked as the safest strategy for the prevention of any bleeding (p-score: 0.704), followed by OAC alone (p-score: 0.476) and DAPT (p-score: 0.437). Consistent results were observed for major bleeding. The incidence of cardiovascular death and secondary ischemic endpoints did not differ among the tested antithrombotic approaches. In patients with indication for long-term anticoagulation, OAC alone showed similar rates of stroke (OR: 0.92 [95% CI: 0.41-2.05], p = 0.83) and reduced occurrence of any bleeding (OR: 0.49 [95% CI: 0.37-0.66], p < 0.01) versus OAC + SAPT.

CONCLUSION

 The present network meta-analysis supports after TAVI the use of SAPT in patients without indication for OAC and OAC alone in those needing long-term anticoagulation.

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.

Aspirin Alone Versus Dual Antiplatelet Therapy After Transcatheter Aortic Valve Implantation: A Systematic Review and Patient-Level Meta-Analysis

Background In patients undergoing transcatheter aortic valve implantation without an indication for oral anticoagulation, it is unclear whether single or dual antiplatelet therapy (DAPT) is necessary to minimize both the bleeding and thromboembolic risk. In this patient-level meta-analysis, we further investigate the effect of aspirin alone compared with DAPT for preventing both thromboembolic and bleeding events after transcatheter aortic valve implantation. Methods and Results We conducted a systematic review of all available randomized controlled trials comparing aspirin with DAPT. In total, 1086 patients were included across 4 eligible trials. The primary outcomes were the composite of all-cause mortality, major or life-threatening bleeding, stroke or myocardial infarction (first composite outcome), and the same composite excluding bleeding (second composite outcome), both tested at 30 days and 3 months. The first composite outcome occurred significantly less in the aspirin-alone group at 30 days (10.3% versus 14.7%, odds ratio [OR], 0.67; 95% CI, 0.46-0.97, P=0.034) and 3 months (11.0% versus 16.5%, hazard ratio [HR], 0.66; 95% CI, 0.47-0.94, P=0.02), compared with the DAPT group. The second composite outcome occurred in 5.5% and 6.6% at 30 days (OR, 0.83; 95% CI, 0.50-1.38, P=0.47) and in 6.9% and 8.5% at 3 months in the aspirin-alone group compared with the DAPT group (HR, 0.82; 95% CI, 0.52-1.29, P=0.39), respectively. Conclusions In patients without an indication for oral anticoagulation undergoing transcatheter aortic valve implantation, aspirin alone significantly reduced the composite of thromboembolic and bleeding events, and does not increase the composite of thromboembolic events after transcatheter aortic valve implantation, compared with DAPT.

Antithrombotic therapy in patients undergoing transcatheter aortic valve replacement: the complexity of the elderly

Along with epidemiologic transitions of the global population, the burden of aortic stenosis (AS) is rapidly increasing and transcatheter aortic valve replacement (TAVR) has quickly spread; indeed, it is nowadays also employed in treating patients with AS at intermediate operative risk. Nonetheless, the less invasive interventional strategy still carries relevant issues concerning post-procedural optimal antithrombotic strategy, given the current indications provided by guidelines are not completely supported by evidence-based data. Geriatric patients suffer from high bleeding and thromboembolic risks, whose balance is particularly subtle due to the presence of concomitant conditions, such as atrial fibrillation and chronic kidney disease, that make the post-TAVR antithrombotic management particularly insidious. This scenario is further complicated by the lack of specific evidence regarding the 'real-life' complex conditions typical of the geriatric syndromes, thus, the management of such a heterogeneous population, ranging from healthy ageing to frailty, is far from being defined. The aim of the present review is to summarize the critical points and the most updated evidence regarding the post-TAVR antithrombotic approach in the geriatric population, with a specific focus on the most frequent clinical settings.

Aspirin Versus Dual Antiplatelet Therapy in Patients Undergoing Trans-Catheter Aortic Valve Implantation, Updated Meta-Analysis

BACKGROUND

The Antiplatelet Therapy for Patients Undergoing Transcatheter Aortic-Valve Implantation (POPular TAVI) trial reported comparable composite endpoints of ischemic events using aspirin compared to dual antiplatelet therapy (DAPT). However, this trial was not powered to detect individual differences in ischemic events. We sought to conduct a meta-analysis to compare aspirin to DAPT on ischemic and bleeding events following TAVI.

METHODS

The MEDLINE database was searched from inception until September 2020 and only randomized clinical trials of patients receiving antiplatelet therapy following TAVI were included. The treatment effect was reported as rate ratios (RRs) with 95% confidence intervals.

RESULTS

Four randomized clinical trials of 1086 TAVI patients were included. There was a 51% reduction in major or life-threatening bleeding with aspirin compared with DAPT [RR 0.49, (95%CI 0.31 to 0.78)]. Aspirin was not associated with an increased risk of death [RR 1.01, (95%CI 0.62 to 1.65)], cardiovascular death [RR 1.15, (95%CI 0.56 to 2.36)], ischemic stroke [RR 0.93, (95%CI 0.51 to 1.70)], or MI [RR 0.53, (95%CI 0.18 to 1.57)].

CONCLUSIONS

This meta-analysis supports the use of aspirin as the optimal antiplatelet strategy following TAVI procedures in reducing bleeding without an increase in ischemic events compared with dual antiplatelet therapy.

Aspirin Alone Versus Dual Antiplatelet Therapy after Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

BACKGROUND

The current American College of Cardiology and American Heart Association (ACC/AHA) guidelines recommend dual antiplatelet therapy (DAPT) with aspirin and clopidogrel for 6 months followed by lifelong aspirin after transcatheter aortic valve replacement (TAVR). However, studies that have DAPT with aspirin following TAVR have questioned this recommendation as DAPT has been associated with more bleeding events compared to aspirin. We performed a systematic review and meta-analysis of all the RCTs comparing DAPT (aspirin plus clopidogrel) with aspirin alone as antithrombotic treatment following transcatheter aortic valve replacement.

METHODS

The databases of Embase, PubMed, and Cochrane library were searched from inception to Oct 1, 2020, and randomized controlled trials (RCTs) reporting aspirin plus clopidogrel with aspirin alone as antithrombotic treatment after TAVI were included. Revman 5.3 was used to conduct the analysis.

RESULTS

After screening 152 articles, four studies involving 1086 patients (541 patients in the aspirin group and 545 patients in the DAPT group) were included. The results demonstrated that, at 30 days follow-up, compared with DAPT, aspirin was not associated with a statistically significant difference in the rate of bleeding events (RR = 1.22, 95% CI 0.62 to 2.39, P = 0.57), all-cause mortality (RR = 1.21, 95% CI 0.52 to 2.84, P = 0.66), stroke (RR = 0.81, 95% CI 0.24 to 2.79, P = 0.74), and MI (RR = 4.00, 95% CI 0.45 to 35.22, P = 0.21). However, at the 6 to 12 months follow-up, DAPT appeared to increase the risk of bleeding events compared with aspirin alone (RR = 1.67, 95% CI 1.24 to 2.24, P < 0.001), and there was no significant difference in the rate of all-cause mortality (RR = 0.89, 95% CI 0.53 to 1.48, P = 0.65), stroke (RR = 1.04, 95% CI 0.57 to 1.92, P = 0.90), and MI (RR = 1.65, 95% CI 0.52 to 5.26, P = 0.40) among the two groups.

CONCLUSIONS

Our systematic review and meta-analysis suggested that aspirin alone could decrease the risk of bleeding and was not associated with higher risk of mortality, stroke or myocardial infarction compared with DAPT.

Adjunctive Antithrombotic Therapy for Patients With Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement

Importance

Transcatheter aortic valve replacement (TAVR) is an established alternative to surgery for patients with severe symptomatic aortic stenosis. Adjunctive antithrombotic therapy used to mitigate thrombotic risks in patients undergoing TAVR must be balanced against bleeding complications, since both are associated with increased mortality.

Observation

Stroke risk associated with TAVR is lower than that associated with surgical aortic valve replacement in recent trials including patients at intermediate or low risk, but it is constant beginning at the time of implant and accrues over time based on patient risk factors. Patients with aortic stenosis undergoing TAVR also have a sizable risk of life-threatening or major bleeding. Although dual antiplatelet therapy for 3 to 6 months after TAVR is the guideline-recommended regimen, this practice is not well supported by current evidence. In patients with no indication for oral anticoagulation, current registry-based evidence suggests that single antiplatelet therapy may be safer than dual antiplatelet therapy. Similarly, oral anticoagulation monotherapy appears superior to anticoagulation plus antiplatelet therapy in those where oral anticoagulant use is indicated. To date, no risk prediction models have been established to guide antithrombotic therapy.

Conclusions and Relevance

Despite the growing volume of TAVR procedures to treat patients with severe aortic stenosis, evidence for adjunctive antithrombotic therapy remains rather scarce. Ongoing clinical trials will provide better understanding to guide antithrombotic therapy.

Randomized Trial of Aspirin Versus Warfarin After Transcatheter Aortic Valve Replacement in Low-Risk Patients

BACKGROUND

The optimal antithrombotic regimen after transcatheter aortic valve replacement remains unclear.

METHODS

In this randomized open-label study, low-risk patients undergoing transfemoral transcatheter aortic valve replacement at 7 centers in the United States were randomized 1:1 to low-dose aspirin or warfarin plus low-dose aspirin for 30 days. Patients who could not be randomized were enrolled in a separate registry. Computed tomography or transesophageal echocardiography was performed at 30 days. The primary effectiveness end point was a composite of the following at 30 days: hypoattenuated leaflet thickening, at least moderately reduced leaflet motion, hemodynamic dysfunction (mean aortic valve gradient ≥20 mm Hg, effective orifice area ≤1.0 cm², dimensionless valve index <0.35, or moderate or severe aortic regurgitation), stroke, or transient ischemic attack.

RESULTS

Between July 2018 and October 2019, 94 patients were randomly assigned, 50 to aspirin and 44 to warfarin plus aspirin, and 30 were enrolled into the registry. In the intention-to-treat analysis of the randomized cohort, the composite primary effectiveness end point was met in 26.5% for aspirin versus 7.0% for warfarin plus aspirin (P=0.014; odds ratio, 4.8 [95% CI, 1.3-18.3]). The rate of hypoattenuated leaflet thickening was 16.3% for aspirin versus 4.7% for warfarin plus aspirin (P=0.07; odds ratio, 4.0 [95% CI, 0.8-20.0]). There was no excess bleeding at 30 days with anticoagulation. In the as-treated analysis of pooled randomized and registry cohorts, the rate of hypoattenuated leaflet thickening was 16.7% for aspirin versus 3.1% for warfarin plus aspirin (P=0.011; odds ratio, 6.3 [95% CI, 1.3-30.6]).

CONCLUSIONS

In low-risk transcatheter aortic valve replacement patients, anticoagulation with warfarin may prevent transcatheter heart valve dysfunction in the short term without excess bleeding. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03557242.

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.

Novel Perspective for Antithrombotic Therapy in TAVI

:

While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

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.

Transcatheter Aortic Valve Implantation Current Indications and Future Directions

Degenerative heart valve disease is associated with significant morbidity and mortality and healthcare expenditures. Transcatheter heart valve repair and replacement has introduced a fundamental change in the therapeutic management and transcatheter aortic valve replacement (TAVR) has gained substantial popularity. Favorable results from randomized trials and large real world registries lead to TAVR being considered a standard procedure with high rates of procedural success and low rates of peri-procedural complications. This article aims to review the past evolution, summarize the available evidence, discuss current indications and limitations and venture a glimpse into the future of percutaneous interventions for aortic valve disease.

Antithrombotic Therapy for Percutaneous Cardiovascular Interventions: From Coronary Artery Disease to Structural Heart Interventions

Percutaneous cardiovascular interventions have changed dramatically in recent years, and the impetus given by the rapid implementation of novel techniques and devices have been mirrored by a refinement of antithrombotic strategies for secondary prevention, which have been supported by a significant burden of evidence from clinical studies. In the current manuscript, we aim to provide a comprehensive, yet pragmatic, revision of the current available evidence regarding antithrombotic strategies in the domain of percutaneous cardiovascular interventions. We revise the evidence regarding antithrombotic therapy for secondary prevention in coronary artery disease and stent implantation, the complex interrelation between antiplatelet and anticoagulant therapy in patients undergoing percutaneous coronary intervention with concomitant atrial fibrillation, and finally focus on the novel developments in the secondary prevention after structural heart disease intervention. A special focus on treatment individualization is included to emphasize risk and benefits of each therapeutic strategy.

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.

In-Hospital Outcomes After Transcatheter Aortic Valve Implantation in Patients With Versus Without Chronic Thrombocytopenia

Patients with chronic thrombocytopenia (cTCP) were excluded from the pivotal transcatheter aortic valve implantation (TAVI) trials. The National Inpatient Sample was queried and propensity score matching was performed to evaluate the prevalence and impact of cTCP on in-hospital clinical outcomes after TAVI. The main outcome was in-hospital mortality in patients with versus without cTCP. Among 38,855 TAVI hospitalizations, 7,105 had a diagnosis of cTCP (18.3%). In-hospital mortality was similar in both groups (OR_adjusted 0.79; 95% confidence interval [CI] 0.57 to 1.09); however, cTCP was associated with higher risk of acute kidney injury (OR_adjusted 1.29; 95% CI 1.08 to 1.54), vascular complications (OR_adjusted 1.99; 95% CI 1.22 to 3.25), perioperative blood product transfusion (OR_adjusted 1.69; 95% CI 1.42 to 2.01), cardiac tamponade (OR_adjusted 4.04; 95% CI 1.51 to 10.82), cardiogenic shock (OR_adjusted 1.52; 95% CI 1.07 to 2.15), and use of extracorporeal membrane oxygenation (OR_adjusted 2.32; 95% CI 1.1 to 4.9). In conclusion, cTCP is common in patients who underwent TAVI and is associated with worse postprocedure clinical outcomes, however, with similar in-hospital mortality.

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.