Direct Oral Anticoagulants Versus Antiplatelet Therapy After Transcatheter Aortic Valve Replacement: A Meta-Analysis of Randomized Trials

Hematological Complications From Transcatheter Aortic Valve Replacement (TAVR): Recognition and Treatment

Transcatheter aortic valve replacement (TAVR) has emerged as a pivotal intervention for patients with severe aortic stenosis who are at high or prohibitive surgical risk. Although TAVR is a minimally invasive procedure, it is linked to serious hematological problems, most notably thrombosis and bleeding. Numerous factors, such as procedural features, patient comorbidities, and anticoagulation management techniques, contribute to these complications. Bleeding complications can be major, minor, or life-threatening. They can be caused by problems with the vascular access site, anticoagulation medication, or coexisting conditions like renal dysfunction and frailty. Hemoglobin drop, overt bleeding, and hematoma signs must all be closely watched to identify bleeding. Careful selection and modification of anticoagulation medication, the use of vascular closure devices, and timely attention to bleeding sites are examples of management techniques. Thrombotic consequences, which include cerebrovascular accidents and valve thrombosis, are caused by endothelial injury, stent implantation, and patient hypercoagulability. Imaging modalities such as computed tomography and transesophageal echocardiography are used in the crucial process of detection. The goal of preventive care is to maximize anticoagulation regimens that are customized to each patient's risk profile, frequently striking a balance between the risk of thrombosis and bleeding. A multidisciplinary strategy that integrates surgical, hematological, and cardiology expertise is necessary for the effective management of these hematological complications. To improve patient outcomes, ongoing research attempts to improve risk stratification and create safer anticoagulation protocols. This review emphasizes how critical it is to identify bleeding and thrombotic events as soon as possible and treat them promptly to reduce the risk of negative outcomes for TAVR patients.

Bioprosthetic Aortic Valve Thrombosis: Definitions, Clinical Impact, and Management: A State-of-the-Art Review

Bioprosthetic aortic valve thrombosis is frequently detected after transcatheter and surgical aortic valve replacement due to advances in cardiac computed tomography angiography technology and standardized surveillance protocols in low-surgical-risk transcatheter aortic valve replacement trials. However, evidence is limited concerning whether subclinical leaflet thrombosis leads to clinical adverse events or premature structural valve deterioration. Furthermore, there may be net harm in the form of bleeding from aggressive antithrombotic treatment in patients with subclinical leaflet thrombosis. This review will discuss the incidence, mechanisms, diagnosis, and optimal management of bioprosthetic aortic valve thrombosis after transcatheter aortic valve replacement and bioprosthetic surgical aortic valve replacement.

Antithrombotic Management for Transcatheter Aortic Valve Implantation

BACKGROUND

There have been significant changes in the optimal antithrombotic regimen post transcatheter aortic valve implantation (TAVI) after the results of major clinical trials in the past few years. Given the clinical importance of the optimal antithrombotic therapy post TAVI, we performed a narrative description of the major clinical trials behind the scientific evidence supporting these changes, as well the current guideline recommendations and knowledge gaps.

METHODS

We performed a narrative description of the major clinical trials behind the scientific evidence supporting these changes. We used PubMed as a major source to collect the major clinical trials including the following key words: "transcatheter aortic valve replacement", "transcatheter aortic valve implantation", "antithrombotic", "antiplatelet" and "anticoagulation". We selected the major clinical trials on this topic. This is not a systematic review or meta-analysis.

RESULTS

We describe the results of the major clinical trials on antithrombotic therapy post TAVI: POPULAR-TAVI A, POPULAR-TAVI B, ENVISAGE-TAVI AF, GALILEO, ATLANTIS and ADAPT-TAVR trials. Based on the results of these trials, single antiplatelet therapy is recommended post TAVI in patients without concomitant indication for oral anticoagulation or dual antiplatelet therapy, especially in elderly patients. In younger patients, it is advised to evaluate the patient's bleeding and thrombotic risk, and dual antiplatelet therapy may be reasonable in patients with a high thrombotic risk and low bleeding risk. In patients with a concurrent indication for oral anticoagulation or dual antiplatelet therapy, it is recommended to continue oral anticoagulation or dual antiplatelet therapy post TAVI.

CONCLUSION

In most patients without concomitant indication for oral anticoagulation, single antiplatelet therapy is recommended post TAVI.

Antithrombotic therapy with Transcatheter aortic valve replacement

Aortic valve replacement is a necessary management strategy for patients with severe aortic stenosis. The use of transaortic valve replacement (TAVR) has increased significantly over the last decade and now exceeds traditional surgical aortic valve replacement. Since the valve systems used in TAVR consist of bioprosthetic valve tissue encased in a metal stent frame, antithrombotic therapy recommendations cannot be extrapolated from prior data with differently constructed surgical bioprosthetic or mechanical valves. Data on the use of antithrombotic therapy with TAVR are a rapidly developing area of medicine. Choice of agents depends on several patient factors. Patients undergoing TAVR also have a relatively high incidence of subclinical valve thrombosis. The clinical impact of this phenomenon and the implications for antithrombotic therapy continue to evolve. It is critical for clinicians who treat patients undergoing TAVR to have a firm understanding of practice guidelines, the evolving evidence, and its implications for the use of antithrombotic therapy in these patients.

The Efficacy and Safety of Direct Oral Anticoagulants versus Standard of Care in Patients without an Indication of Anti-Coagulants after Transcatheter Aortic Valve Replacement: A Meta-Analysis of Randomized Controlled Trials

Transcatheter aortic valve replacement (TAVR) is now considered the mainstay of aortic stenosis management; however, the optimal antithrombotic therapy in patent without indications for an oral anticoagulant (OAC) is yet to be identified. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of direct oral anticoagulant (DOAC) treatment versus the standard of care in patients without indications of OACs after TAVR. We synthesized randomized controlled trials (RCTs) from Web of Science, SCOPUS, EMBASE, PubMed, and Cochrane until 18 August 2022. We used the risk ratio (RR) for dichotomous outcomes with the corresponding 95% confidence interval (CI). We registered our protocol in PROSPERO with ID: CRD42022357027. Three RCTs with 2922 patients were identified. DOACs were significantly associated with higher incidence of all-cause mortality (RR: 1.68 with 95% CI [1.22, 2.30], p = 0.001), mortality due to non-cardiovascular causes (RR: 2.34 with 95% CI [1.36, 4.02], p = 0.002), and the composite outcome of death, myocardial infarction, or stroke (RR: 1.41 with 95% CI [1.13, 1.76], p = 0.002). However, DOACs were associated with decreased incidence of reduced leaflet motion (RLM) (RR: 0.19 with 95% CI [0.09, 0.41], p = 0.0001) and hypoattenuated leaflet thickening (HALT) (RR: 0.50 with 95% CI [0.36, 0.70], p = 0.0001). DOACs were effective to reduce RLM and HALT; however, the clinical effect of this is still controversial. DOACs were associated with worse efficacy and safety outcomes, including all-cause mortality. Further RCTs investigating the optimal antithrombotic regimen after TAVR.