Thrombo-embolic prevention after transcatheter aortic valve implantation

Perioperative changes in coagulation and platelet contribution to clot strength after transcatheter aortic valve implantation: A study using thromboelastography and conventional markers

INTRODUCTION

Thrombotic and haemorrhagic complications have been reported following transcatheter aortic valve implantation (TAVI). However, few reports have studied perioperative changes in coagulation and platelet function after TAVI. Furthermore, there are no clear guidelines for antithrombotic therapy. This study aimed to examine the perioperative changes in coagulation and platelet contribution to clot strength after TAVI using thromboelastography (TEG 6s; Hemonetics).

METHODS

This prospective observational study included 15 patients scheduled to undergo TAVI for severe aortic stenosis. TEG 6s global haemostasis was used to record three measurements: on the day of surgery (immediately before the operation) and postoperative days 1 and 3. The reaction time R to thrombosis; K and α, which represent the rate of thrombosis; and the maximum amplitude (MA) were measured from the kaolin thromboelastography (TEG) curves. The coagulation index (CI) was calculated from the measurement results to assess thrombotic tendency. In addition, MA was converted to elastic clot strength, and platelet function was assessed by the difference, Gp, in elastic strength depending on platelet activation.

RESULTS

R and K decreased, and α tended to increase in kaolin TEG on days 1 and 3 after TAVI, indicating elevated coagulation function compared with the preoperative period, but MA and CI did not show significant changes. Gp decreased significantly on days 1 and 3, suggesting a decrease in the platelet contribution to clot strength.

CONCLUSIONS

Compared with the preoperative period, coagulation tended to increase, and platelet contribution to clot strength decreased from days 1 to 3 after TAVI.

A Propensity-Matched National Analysis of Transcatheter Aortic Valve Implantation Outcome in Patients With Gastrointestinal Bleeding

Gastrointestinal (GI) bleeding is often observed in severe aortic stenosis, which can be attributed to the presence of arteriovenous malformations and von Willebrand's factor deficiency. GI is one of the most common complications in patients who underwent transcatheter aortic valve implantation (TAVI). The outcome of the TAVI procedure with GI bleeding is unknown. We performed an International Classification of Diseases, Tenth Revision-based national cohort analysis using the national readmission database from 2016 to 2020. We compared cardiovascular outcomes, mortality, and readmission rates of patients with TAVI who developed GI bleeding compared with those who had no GI bleeding. A total of 320,353 hospitalizations with TAVI were identified from the year 2016 to 2020. Patients with TAVI with GI bleeding were 6,193.37 and without GI bleeding were 314,160. The median age of the patients with TAVI with GI or without GI bleeding was 80. GI bleed patients had statistically significantly higher readmission rates at 30, 90, and 180 days and they had higher odds of in-hospital mortality (adjusted odds ratio [aOR] = 6.35; 95% confidence interval [CI]: 5.37 to 7.52; p <0.0001), acute kidney injury (aOR = 5.22; 95% CI:4.75 to 5.74; p <0.0001), stroke (aOR = 2.83; 95% CI 2.05 to 3.91 p:0.0001, postprocedural bleeding (aOR: 1.76; 95% CI: 1.35 to 2.30; p:0.0001), cardiac tamponade (aOR = 2.54; 95% CI 1.86 to 3.49; p <0.0001), use of mechanical circulatory support (aOR: 5.33; 95% CI:4.13 to 6.86; p <0.0001), and heart failure (aOR:1.73; 95%CI: 1.54 to 1.94; p <0.0001). The total cost of hospitalization and length of stay was higher in the GI bleed group. Patients with TAVI with GI bleeding have worse clinical outcomes and higher in-hospital mortality and readmission rates compared with patients with no GI bleeding.

Effectiveness of aortic valve replacement in Heyde syndrome: a meta-analysis

AIMS

Heyde syndrome is the co-occurrence of aortic stenosis, acquired von Willebrand syndrome, and gastrointestinal bleeding. Aortic valve replacement has been demonstrated to resolve all three associated disorders. A systematic review and meta-analysis were performed to obtain best estimates of the effect of aortic valve replacement on acquired von Willebrand syndrome and gastrointestinal bleeding.

METHODS AND RESULTS

A literature search was performed to identify articles on Heyde syndrome and aortic valve replacement up to 25 October 2022. Primary outcomes were the proportion of patients with recovery of acquired von Willebrand syndrome within 24 h (T1), 24-72 h (T2), 3-21 days (T3), and 4 weeks to 2 years (T4) after aortic valve replacement and the proportion of patients with cessation of gastrointestinal bleeding. Pooled proportions and risk ratios were calculated using random-effects models. Thirty-three studies (32 observational studies and one randomized controlled trial) on acquired von Willebrand syndrome (n = 1054), and 11 observational studies on gastrointestinal bleeding (n = 300) were identified. One study reported on both associated disorders (n = 6). The pooled proportion of Heyde patients with acquired von Willebrand syndrome recovery was 86% (95% CI, 79%-91%) at T1, 90% (74%-96%) at T2, 92% (84%-96%) at T3, and 87% (67%-96%) at T4. The pooled proportion of Heyde patients with gastrointestinal bleeding cessation was 73% (62%-81%). Residual aortic valve disease was associated with lower recovery rates of acquired von Willebrand syndrome (RR 0.20; 0.05-0.72; P = 0.014) and gastrointestinal bleeding (RR 0.57; 0.40-0.81; P = 0.002).

CONCLUSION

Aortic valve replacement is associated with rapid recovery of the bleeding diathesis in Heyde syndrome and gastrointestinal bleeding cessation. Residual valve disease compromises clinical benefits.

Case report: acute myocardial infarction in the setting of acute transcatheter aortic valve thrombus

We describe a case of valve thrombosis and a subsequent thromboembolic event within only 10 days of transcatheter aortic valve implantation (TAVI). Postprocedural anticoagulants are not standard of care medications post-TAVI in patients without atrial fibrillation. Valve thrombosis is an indication to initiate anticoagulation to resolve and prevent further thrombus.

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.

Evolving Devices and Material in Transcatheter Aortic Valve Replacement: What to Use and for Whom

Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of aortic stenosis, providing a viable alternative to surgical aortic valve replacement (SAVR) for patients deemed to be at prohibitive surgical risk, but also for selected patients at intermediate or low surgical risk. Nonetheless, there still exist uncertainties regarding the optimal management of patients undergoing TAVR. The selection of the optimal bioprosthetic valve for each patient represents one of the most challenging dilemmas for clinicians, given the large number of currently available devices. Limited follow-up data from landmark clinical trials comparing TAVR with SAVR, coupled with the typically elderly and frail population of patients undergoing TAVR, has led to inconclusive data on valve durability. Recommendations about the use of one device over another in given each patient’s clinical and procedural characteristics are largely based on expert consensus. This review aims to evaluate the available evidence on the performance of different devices in the presence of specific clinical and anatomic features, with a focus on patient, procedural, and device features that have demonstrated a relevant impact on the risk of poor hemodynamic valve performance and adverse clinical events.

Evolving concepts in the management of antithrombotic therapy in patients undergoing transcatheter aortic valve implantation

Thromboembolic and bleeding complications negatively impact recovery and survival after transcatheter aortic valve implantation (TAVI). Particularly, there is a considerable risk of ischaemic stroke and vascular access related bleeding, as well as spontaneous gastro-intestinal bleeding. Therefore, benefit and harm of antithrombotic therapy should be carefully balanced. This review summarizes current evidence on peri- and post-procedural antithrombotic treatment. Indeed, in recent years, the management of antithrombotic therapy after TAVI has evolved from intensive, expert opinion-based strategies, towards a deescalated, evidence-based approach. Besides per procedural administration of unfractionated heparin, this encompasses single antiplatelet therapy in patients without a concomitant indication for oral anticoagulation (OAC); and OAC monotherapy in patients with such indication, mainly being atrial fibrillation. Combination therapy should generally be avoided to reduce bleeding risk, except after recent coronary stenting where a period of dual antiplatelet therapy (aspirin plus P2Y12-inhibitor) or P2Y12-inhibitor plus OAC (in patients with an independent indication for OAC) is recommended to prevent stent thrombosis. This new paradigm in which reduced antithrombotic intensity leads to improved patient safety, without a loss of efficacy, may be particularly suitable for elderly and fragile patients. Whether this holds in upcoming populations of younger and lower-risk patients and in specific populations as patients with subclinical valve thrombosis, is yet to be proven. Finally, whether less intensive or alternative approaches should be also applied for the periprocedural management of the antithrombotic therapy, has to be determined by ongoing and future studies.

Switching from warfarin to direct-acting oral anticoagulants: it is time to move forward!

Oral vitamin K antagonists (VKAs), warfarin, have been in routine clinical use for almost 70 years for various cardiovascular conditions. Direct-Acting Oral Anticoagulants (DOACs) have emerged as competitive alternatives for VKAs to prevent stroke in patients with non-valvular atrial fibrillation (AF) and have become the preferred choice in several clinical indications for anticoagulation. Recent guidelines have limited the use of DOACs to patients with non-valvular AF to reduce the risk of cardioembolic complications and to treat venous thromboembolism (VTE). Although emerging evidence is suggestive of its high efficacy, there was a lack of data to support DOACs safety profile in patients with mechanical valve prosthesis, intracardiac thrombi, or other conditions such as cardiac device implantation or catheter ablation. Therefore, several clinical trials have been conducted to assess the beneficial effects of using DOACs, instead of VKAs, for various non-guideline-approved indications. This review aimed to discuss the current guideline-approved indications for DOACs, advantages, and limitations of DOACs use in various clinical indications highlighting the potential emerging indications and remaining challenges for DOACs use. Several considerations are in favour of switching from warfarin to DOACs including superior efficacy, better adverse effect profile, fewer drug-drug interactions, and they do not require frequent international normalized ratio (INR) monitoring. Large randomized controlled trials are required to determine the safety and efficacy of their use in various clinical indications.

Towards personalized antithrombotic management with drugs and devices across the cardiovascular spectrum

Intravascular thrombus formation and embolization are among the most frequent events leading to a number of cardiovascular conditions with high morbidity and mortality. The underlying causes are stasis of the circulating blood, genetic and acquired coagulation disorders, and reduced antithrombotic or prothrombotic properties of the vascular wall (Virchow's triad). In the venous system, intravascular thrombi can cause venous thrombosis and pulmonary and even peripheral embolism including ischaemic stroke [through a patent foramen ovale (PFO)]. Thrombi in the left atrium and its appendage or ventricle form in the context of atrial fibrillation and infarction, respectively. Furthermore, thrombi can form on native or prosthetic aortic valves, within the aorta (in particular at sites of ulcers, aortic dissection, and abdominal aneurysms), and in cerebral and peripheral arteries causing stroke and critical limb ischaemia, respectively. Finally, thrombotic occlusion may occur in arteries supplying vital organs such the heart, brain, kidney, and extremities. Thrombus formation and embolization can be managed with anticoagulants and devices depending on where they form and embolize and on patient characteristics. Vitamin K antagonists are preferred in patients with mechanical valves, while novel oral anticoagulants are first choice in most other cardiovascular conditions, in particular venous thromboembolism and atrial fibrillation. As anticoagulants are associated with a risk of bleeding, devices such as occluders of a PFO or the left atrial appendage are preferred in patients with an increased bleeding risk. Platelet inhibitors such as aspirin and/or P2Y12 antagonists are preferred in the secondary prevention of coronary artery disease, stroke, and peripheral artery disease either alone or in combination depending on the clinical condition. A differential and personalized use of anticoagulants, platelet inhibitors, and devices is recommended and reviewed in this article.

CVIT expert consensus document on primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) update 2022

Primary Percutaneous Coronary Intervention (PCI) has significantly contributed to reducing the mortality of patients with ST-segment elevation myocardial infarction (STEMI) even in cardiogenic shock and is now the standard of care in most of Japanese institutions. The Task Force on Primary PCI of the Japanese Association of Cardiovascular Interventional and Therapeutics (CVIT) society proposed an expert consensus document for the management of acute myocardial infarction (AMI) focusing on procedural aspects of primary PCI in 2018. Updated guidelines for the management of AMI were published by the European Society of Cardiology (ESC) in 2017 and 2020. Major changes in the guidelines for STEMI patients included: (1) radial access and drug-eluting stents (DES) over bare-metal stents (BMS) were recommended as a Class I indication, (2) complete revascularization before hospital discharge (either immediate or staged) is now considered as Class IIa recommendation. In 2020, updated guidelines for Non-ST-Elevation Myocardial Infarction (NSTEMI) patients, the followings were changed: (1) an early invasive strategy within 24 h is recommended in patients with NSTEMI as a Class I indication, (2) complete revascularization in NSTEMI patients without cardiogenic shock is considered as Class IIa recommendation, and (3) in patients with atrial fibrillation following a short period of triple antithrombotic therapy, dual antithrombotic therapy (e.g., DOAC and single oral antiplatelet agent preferably clopidogrel) is recommended, with discontinuation of the antiplatelet agent after 6 to 12 months. Furthermore, an aspirin-free strategy after PCI has been investigated in several trials those have started to show the safety and efficacy. The Task Force on Primary PCI of the CVIT group has now proposed the updated expert consensus document for the management of AMI focusing on procedural aspects of primary PCI in 2022 version.

Efficacy and safety of antithrombotic therapy with non-vitamin K antagonist oral anticoagulants after transcatheter aortic valve replacement: a systematic review and meta-analysis

Objective:

A meta-analysis was performed to compare the efficacy and safety of antithrombotic therapy with non-vitamin K antagonist oral anticoagulants (NOACs) versus standard care in patients after successful transcatheter aortic valve replacement (TAVR).

Methods:

A systematic search of PubMed, Cochrane Central Register of Controlled Trials, and EMBASE databases and ClinicalTrials.gov website (through 21 October 2020) was performed. Risk ratios (RRs) with 95% confidence intervals (CIs) for all outcomes were calculated using random-effects models.

Results:

Twelve studies (two studies were randomized controlled trials) comprising 6943 patients were included (5299 had indications for oral anticoagulation (OAC) and 1644 had none). No significant differences were found between NOACs and the standard care in the incidences of all stroke, a composite endpoint, and major/life-threatening bleeding. NOACs were associated with lower all-cause mortality than vitamin K antagonists (VKAs) in post-TAVR patients with indications for OAC after more than 1 year of follow-up [RR = 0.64; 95% CI, (0.42, 0.96); p = 0.03], whereas NOACs exhibited poor outcomes than antiplatelet therapy (APT) in patients without indications for OAC [RR = 1.66; 95% CI, (1.12, 2.45); p = 0.01]. In the prevention of valve thrombosis, NOACs and VKAs were not significantly different in patients with indications for OAC [RR = 0.66; 95% CI, (0.24, 1.84); p = 0.43], whereas NOACs were better than APT in patients without indications for OAC [RR = 0.19; 95% CI, (0.04, 0.83); p = 0.03].

Conclusions:

In patients with indications for OAC, post-TAVR antithrombotic therapy with NOACs was more favorable due to its lower all-cause mortality after more than 1 year of follow-up. In those without indications for OAC, NOACs presented poorer outcomes due to its higher all-cause mortality.

Major threats to early safety after transcatheter aortic valve implantation in a contemporary cohort of real-world patients

INTRODUCTION

Despite considerable advances in the last decade, major adverse events remain a concern after transcatheter aortic valve implantation (TAVI). The aim of this study was to provide a detailed overview of their underlying causes and contributing factors in order to identify key domains for quality improvement.

METHODS

This observational, prospective registry included all patients undergoing TAVI between 31 December 2015 and 1 January 2020 at the St. Antonius Hospital in Nieuwegein and the University Medical Centre in Utrecht. Outcomes of interest were all-cause mortality, stroke, major bleeding, life-threatening or disabling bleeding, major vascular complications, myocardial infarction, severe acute kidney injury and conduction disturbances requiring permanent pacemaker implantation within 30 days after TAVI, according to the Valve Academic Research Consortium‑2 criteria.

RESULTS

Of the 1250 patients who underwent TAVI in the evaluated period, 146 (11.7%) developed a major complication. In 54 (4.3%) patients a thromboembolic event occurred, leading to stroke in 36 (2.9%), myocardial infarction in 13 (1.0%) and lower limb ischaemia in 11 (0.9%). Major bleeding occurred in 65 (5.2%) patients, most frequently consisting of acute cardiac tamponade (n = 25; 2.0%) and major access-site bleeding (n = 21; 1.7%). Most complications occurred within 1 day of the procedure. Within 30 days a total of 54 (4.3%) patients died, the cause being directly TAVI-related in 30 (2.4%). Of the patients who died from causes that were not directly TAVI-related, 14 (1.1%) had multiple hospital-acquired complications.

CONCLUSION

A variety of underlying mechanisms and causes form a wide spectrum of major threats affecting early safety in 11.7% of patients undergoing TAVI in a contemporary cohort of real-world patients.

[Perioperative management of platelet function and anticoagulation in geriatric patients]

Geriatric patients often have cardiovascular diseases that require differentiated perioperative management of hemostasis. The operation-related bleeding risk and the individual thromboembolism risk mutually influence each other, so that a differentiated preoperative assessment of the further prescription of coagulation-modulating medication is required. In many cases the active coagulation medication can be interrupted without replacement or continued unchanged. In cardiovascular diseases with antiplatelet medication, the preoperative risk-benefit assessment for most operations leads to the continuation of previous platelet aggregation inhibitor monotherapy; however, if there is a high risk of cardiovascular thromboembolism with dual platelet inhibition, the individual perioperative medication should be closely coordinated with a geriatrician or cardiologist.In most cases, the intake of vitamin K antagonists (VKA) can be preoperatively interrupted. In cases of high risk of thromboembolism, a temporary bridging with heparin must be carried out. The introduction of the four new direct oral antagonists (DOAC) has made the perioperative management of anticoagulation much easier. Bridging with heparin is not necessary. Perioperatively, only the dosage and timing of interruption of the DOACs have to be determined individually depending on the operative bleeding risk as well as the age, body weight and kidney function of the patient. If bleeding complications arise under the influence of the DOACs, antidotes are available for three of the four DOACs, which in acute cases can be used in addition to prothrombin complex concentrates and fresh frozen plasma to normalize coagulation.

Long-Term Stability and Biocompatibility of Pericardial Bioprosthetic Heart Valves

The use of bioprostheses for heart valve therapy has gradually evolved over several decades and both surgical and transcatheter devices are now highly successful. The rapid expansion of the transcatheter concept has clearly placed a significant onus on the need for improved production methods, particularly the pre-treatment of bovine pericardium. Two of the difficulties associated with the biocompatibility of bioprosthetic valves are the possibilities of immune responses and calcification, which have led to either catastrophic failure or slow dystrophic changes. These have been addressed by evolutionary trends in cross-linking and decellularization techniques and, over the last two decades, the improvements have resulted in somewhat greater durability. However, as the need to consider the use of bioprosthetic valves in younger patients has become an important clinical and sociological issue, the requirement for even greater longevity and safety is now paramount. This is especially true with respect to potential therapies for young people who are afflicted by rheumatic heart disease, mostly in low- to middle-income countries, for whom no clinically acceptable and cost-effective treatments currently exist. To extend longevity to this new level, it has been necessary to evaluate the mechanisms of pericardium biocompatibility, with special emphasis on the interplay between cross-linking, decellularization and anti-immunogenicity processes. These mechanisms are reviewed in this paper. On the basis of a better understanding of these mechanisms, a few alternative treatment protocols have been developed in the last few years. The most promising protocol here is based on a carefully designed combination of phases of tissue-protective decellularization with a finely-titrated cross-linking sequence. Such refined protocols offer considerable potential in the progress toward superior longevity of pericardial heart valves and introduce a scientific dimension beyond the largely disappointing 'anti-calcification' treatments of past decades.

Antithrombotic Treatment After Surgical and Transcatheter Heart Valve Repair and Replacement

New antithrombotic drugs have been developed, new valve types have been designed and minimally invasive transcatheter techniques have emerged, making the choice of antithrombotic therapy after surgical or transcatheter heart valve repair and replacement increasingly complex. Moreover, due to a lack of large randomized controlled trials many recommendations for antithrombotic therapy are based on expert opinion, reflected by divergent recommendations in current guidelines. Therefore, decision-making in clinical practice regarding antithrombotic therapy for prosthetic heart valves is difficult, potentially resulting in sub-optimal patient treatment. This article compares the 2017 ESC/EACTS and 2020 ACC/AHA guidelines on the management of valvular heart disease and summarizes the available evidence. Finally, we established a convenient consensus on antithrombotic therapy after valve interventions based on over 800 annual cases of surgical and transcatheter heart valve repair and replacement and a multidisciplinary team discussion between the department of cardiovascular diseases and cardiac surgery of the University Hospitals Leuven, Belgium.

Comparison of Warfarin to Dual Antiplatelet Therapy Following Transcatheter Aortic Valve Replacement

INTRODUCTION

Dual antiplatelet therapy (DAPT) was the initial antithrombotic regimen of choice following transcatheter aortic valve replacement (TAVR). Subsequent identification of subclinical valve thrombosis in high-risk patients has questioned whether warfarin should be used as an alternative to DAPT for some patients.

OBJECTIVE

The aim of this study was to compare thromboembolic events, bleeding, and all-cause mortality between DAPT and warfarin following TAVR.

METHODS

This was a single-center, retrospective review of TAVR patients who received DAPT or warfarin following TAVR between 2008 and 2018. The primary endpoint was occurrence of thromboembolic events during the hospital stay and 1-year follow-up, while secondary endpoints included bleeding and all-cause mortality.

RESULTS

Of the included 764 patients, 193 received DAPT and 571 received warfarin. The median Society of Thoracic Surgeons (STS) Predicted Risk of Mortality (PROM) scores were 8.3% for the DAPT group and 6.5% for the warfarin group. The primary endpoint occurred 30 times (3.9%) during the study timeframe. No differences in thromboembolic events between the DAPT and warfarin groups were found (4.14% vs. 3.85%; p = 0.857), and there was no difference in bleeding (6.22% vs. 5.08%; p = 0.544) or risk of mortality (hazard ratio 0.59, 95% confidence interval 0.33-1.06; p = 0.076).

CONCLUSIONS

In this study, warfarin had similar effectiveness and safety, compared with DAPT, for antithrombotic management post-TAVR. For patients whom the provider deemed anticoagulation is indicated, our data suggest warfarin is a well-tolerated option following TAVR in intermediate- and high-risk STS score patients.

Blood Coagulation Changes With or Without Direct Oral Anticoagulant Therapy Following Transcatheter Aortic Valve Implantation

Thromboembolic events remain clinically unresolved after transcatheter aortic valve implantation (TAVI). The use of direct oral anticoagulant (DOAC) to reduce thrombosis associated with TAVI remains controversial. This study aimed at investigating the periprocedural change in blood coagulation and thrombolysis parameters in 199 patients undergoing transfemoral TAVI. Prothrombin activation fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), soluble fibrin monomer complex (SFMC), and fibrin/fibrinogen degradation product (FDP) levels were measured before and 1 hour after TAVI and 1, 2, and 7 days postoperatively. Of the 199 patients, 49 were treated with DOAC (apixaban in 32, edoxaban in 10, and rivaroxaban in 7). The F1 + 2 and TAT levels immediately increased 1 hour after TAVI and then gradually decreased in both groups. The SFMC level also significantly increased with a peak on day 1. The FDP level gradually increased, peaking on day 2. The values of F1 + 2, TAT, SFMC, and FDP in patients who used DOAC were significantly lower than those who did not use DOAC at 1 hour after TAVI in F1 + 2 (600 [452 to 765] vs 1055 [812 to 1340] pmol/L; p < 0.001), TAT (21.4 [16.2 to 37.0] vs 38.7 [26.4 to 58.7] μg/mL; p < 0.001) and on day 1 in SFMC (18.2 [9.4 to 57.9] vs 113.4 [70.9 to 157.3] μg/mL; p < 0.001) and day 2 in FDP (6.0 [4.7 to 10.0] vs 12.6 [8.2 to 17.4] μg/mL; p < 0.001). Ischemic stroke within 30 days after TAVI occurred in 3 patients (1.5%), who were not treated with DOAC. Coagulation cascade activation was observed after TAVI. DOAC could reduce transient hypercoagulation following TAVI.

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.

Antithrombotic therapy with or without clopidogrel after transcatheter aortic valve replacement. A meta-analysis of randomized controlled trials

AIMS

To investigate the clinical outcomes associated with an antithrombotic therapy with or without clopidogrel after transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

This is a study-level meta-analysis including all randomized trials investigating antithrombotic regimens after TAVR. The protocol was registered with PROSPERO (CRD42020191036). We searched electronic scientific databases for eligible studies. The primary outcome was all-cause death. Main secondary outcome was major bleeding. Other outcomes were life-threatening (or disabling) bleeding, myocardial infarction (MI) and stroke. Six eligible trials randomly allocated 3056 TAVR patients to aspirin or oral anticoagulation (OAC) with clopidogrel (n = 1525) versus aspirin and/or OAC without clopidogrel (n = 1531). In the overall estimates, an antithrombotic therapy with clopidogrel versus without displayed a comparable risk of all-cause death [Risk Ratio-RR = 0.83, 95% Confidence intervals-CI (0.57-1.20); P = 0.25] and major bleeding [RR = 1.33, 95% CI (0.61-2.92); P = 0.39]. However, the combination of aspirin or OAC with clopidogrel doubled the risk of major bleeding as compared to aspirin or OAC without clopidogrel [RR = 2.08, 95% CI (1.27-3.42); P = 0.015, P for interaction = 0.021]. Treatment strategies did not differ with respect to the risk of life-threatening bleeding, MI and stroke.

CONCLUSIONS

In patients receiving TAVR, a therapeutic strategy of aspirin or OAC with clopidogrel significantly increases the risk of major bleeding without impact on mortality and ischemic outcomes compared to aspirin or OAC without clopidogrel. The performance of different antithrombotic regimens in terms of long-term clinical outcomes and bioprosthesis valve function requires further investigation. Forest plots from pairwise and network meta-analyses associated with an antithrombotic therapy with or without clopidogrel Risk ratio for all outcomes of interest calculated with the pairwise meta-analysis (left side) and for main outcomes calculated with the network meta-analysis (right side) in patients allocated to an antithrombotic therapy with clopidogrel or without. The diamonds indicate the point estimate and the left and the right ends of the lines the [95% CI]. CI: Confidence intervals; OAC; oral anticoagulation.

Don't Trust the Imaging: Necrotic Bowel Following Transcatheter Aortic Valve Replacement Through Aortic Stent Graft

Mesenteric ischemia is a rare but lethal complication of transcatheter aortic valve replacement (TAVR). We present a challenging case of an 80-year-old man who had abdominal pain few hours following TAVR. Repeated abdominal and pelvic imaging showed no vascular obstruction, but exploratory laparoscopy revealed a necrotic bowel. (Level of Difficulty: Intermediate.).

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.

Embolization to Two Different Vascular Territories in a Patient With Bicuspid Aortic Stenosis Undergoing Transcatheter Aortic Valve Implantation

We describe the case of an 81-year-old man with symptomatic severe bicuspid aortic valve stenosis. Transfemoral transcatheter aortic valve implantation was performed with a cerebral embolic protection device. During valve deployment, the 29-mm Evolut PRO prosthesis (Medtronic) popped out 3 times and exchanged for a 34-mm Evolut R. Large valvular debris were captured in the embolic protection device. Subsequently, the patient developed chest pain and electrocardiogram modification. An emergency coronary angiography showed an occlusion of the middle circumflex artery. This case demonstrates technical challenges and possible complications in patients with bicuspid aortic valve stenosis undergoing transcatheter aortic valve implantation.

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.

Computed Tomography Features of Cuspal Thrombosis and Subvalvular Tissue Ingrowth after Transcatheter Aortic Valve Implantation

Post-transcatheter aortic valve implantation (TAVI) computed tomography (CT) findings have not been fully elucidated, except hypoattenuating leaflet thickening (HALT). The objective of this study was to describe cardiac CT findings after TAVI, and investigate factors associated with HALT. This retrospective study included patients who underwent TAVI and post-TAVI cardiac CT scans. On CT, abnormal findings such as hypoattenuating subvalvular thickening (HAST), thrombus within the sinus of Valsalva, HALT, and leaflet motion limitation were thoroughly reviewed. Clinical and CT findings were compared between patients with HALT and those without HALT. Logistic regression analysis was performed to determine factors associated with HALT. A total of 138 patients (64 male, mean 78.5 ± 5.2 years of age) with post-TAVI CT scans were included. The median duration from TAVI to CT was 17.5 days (interquartile range, 3 to 390.8 days). HAST and thrombus within the sinus of Valsalva were detected in 32 (23%) and 5 (4%) patients, respectively. HALT and leaflet motion limitations were found in 25 (18%) and 20 (14%) of patients, respectively. Pannus was diagnosed in 2 patients. TAVI device implant duration (odds ratio [OR], 1.5; p = 0.01), hypertension (OR, 0.2; p = 0.03), and HAST (OR, 4.9; p = 0.003) were associated with HALT. Implant durations were longer in patients with HAST, HALT, or leaflet motion limitation (p < 0.05, for all). In conclusion, HAST, HALT, thrombus within the sinus of Valsalva, and leaflet motion limitation are not uncommon after TAVI. Implant duration, hypertension, and HAST are associated with HALT.

Treatment decision for transcatheter aortic valve implantation: the role of the heart team : Position statement paper of the Dutch Working Group of Transcatheter Heart Interventions

The current paper presents a position statement of the Dutch Working Group of Transcatheter Heart Valve Interventions that describes which patients with aortic stenosis should be considered for transcatheter aortic valve implantation and how this treatment proposal/decision should be made. Given the complexity of the disease and the assessment of its severity, in particular in combination with the continuous emergence of new clinical insights and evidence from physiological and randomised clinical studies plus the introduction of novel innovative treatment modalities, the gatekeeper of the treatment proposal/decision and, thus, of qualification for cost reimbursement is the heart team, which consists of dedicated professionals working in specialised centres.

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.

Impact of leaflet thrombosis on hemodynamics and clinical outcomes after bioprosthetic aortic valve replacement: A meta-analysis

BACKGROUND

Leaflet thrombosis (LT, also called cusp thrombosis) detected by multidetector computed tomography (MDCT) is common in bioprosthetic aortic valve replacement (bAVR). However, it remains contradictory whether MDCT-defined LT following bAVR is associated with hemodynamic deterioration and stroke. Thus, we performed the first meta-analysis to assess hemodynamic outcomes and updated the latest researches on the clinical outcomes of MDCT-defined LT after bAVR.

HYPOTHESIS

MDCT-defined LT might be associated with worse hemodynamic and clinical outcomes after bAVR.

METHOD

MEDLINE, EMBASE, Cochrane Library, and ClinicalTrial.gov were searched from inception to 15th April 2019. The fix-effect model was utilized to calculate odds ratio (OR) and 95% confidence interval (CI). The primary outcomes were hemodynamic stability indexes, including mean pressure gradient (MPG), left ventricular ejection fraction (LVEF), paravalvular leak (PVL), and clinical heart failure. The secondary endpoints were major adverse cardiovascular and cerebrovascular events (MACCEs), which consisted of myocardial infarction, all-cause death, stroke, and transient ischemic attack (TIA).

RESULTS

Twelve studies with 4820 patients were included. The total prevalence of MDCT-defined LT was 9.7%. MDCT-defined LT was associated with a significantly increased risk of MPG (inverse variance 0.43, 95% CI: [0.30, 0.57]), MACCEs (OR 2.43, 95% CI: [1.45, 4.06]), stroke (OR 1.79, 95% CI: [1.03, 3.11]), and TIA (OR 4.09, 95% CI: [1.59, 10.54]). There were no differences for other outcomes.

CONCLUSIONS

MDCT-defined LT after bAVR is associated with increased MPG and increased risk of adverse cerebrovascular events, including TIA and stroke. While LVEF, PVL, and clinical heart failure were similar between patient with and without LT.

[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.

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.

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.

Impact of Baseline Atrial Fibrillation on Outcomes Among Women Who Underwent Contemporary Transcatheter Aortic Valve Implantation (from the Win-TAVI Registry)

Pre-existing atrial fibrillation (AF) is common among patients who underwent transcatheter aortic valve implantation (TAVI) and has been associated with adverse outcomes. The specific impact of AF at baseline in women who underwent TAVI, however, remains unknown. The Women's International Transcatheter Aortic Valve Implantation is a prospective, multinational registry evaluating the safety and performance of contemporary TAVI in women in 19 centers between January 2013 and December 2015. Patients with available electrocardiogram at baseline were compared according to the presence of AF. All events were adjudicated according to the Valve Academic Research Consortium 2 criteria. Associations between AF and outcomes were tested using multivariate Cox regression model. Of the 993 women with available baseline electrocardiogram included in the study, 200 (20.1%) presented with AF. Patients with AF at baseline had higher Euroscore I score values and more frequently had chronic kidney disease or prior stroke. Patients without AF more frequently had coronary artery disease. There was no difference regarding in-hospital events between the two groups aside from longer length of stay for patients with AF (13.3 ± 11 vs 11.5 ± 7.1 days, p = 0.01). In multivariate analysis, AF at baseline was associated with an increase of all-cause and cardiovascular death at 12 months (_adjHR 1.67 95%CI 1.11 to 2.50, p = 0.013 and _adjHR 1.85 95%CI 1.19 to 2.86, p = 0.006 respectively). In conclusion, in this prospective registry of women who underwent contemporary TAVI, the presence of AF at baseline was associated with significantly increased 12-month mortality.