Comparative efficacy and safety of antithrombotic therapy for transcatheter aortic valve replacement: a systematic review and network meta-analysis

Meta-Analysis Assessing Efficacy and Safety of Vitamin K Antagonists Versus Direct Oral Anticoagulants for Atrial Fibrillation After Transcatheter Aortic Valve Implantation

Patients who underwent transcatheter aortic valve implantation (TAVI) with concomitant atrial fibrillation (AF) are at a higher risk for thromboembolic and bleeding events. The optimal antithrombotic strategy for patients with AF after TAVI remains unclear. We sought to determine the comparative efficacy and safety of direct oral anticoagulants (DOAC) versus oral vitamin K antagonists (VKAs) in these patients. Electronic databases such as PubMed, Cochrane, and Embase databases were searched till January 31, 2023, for relevant studies evaluating clinical outcomes of VKA versus DOAC in patients with AF after TAVI. Outcomes assessed were (1) all-cause mortality, (2) stroke, (3) major/life-threatening bleeding, and (4) any bleeding. Hazard ratios (HRs) were pooled in meta-analysis using random effect model. Nine studies (2 randomized and 7 observational) were included in systematic review, and 8 studies with 25,769 patients were eligible to be included in the meta-analysis. The mean age of the patients was 82.1 years, and 48.3% were male. Pooled analysis using random-effects model showed no statistically significant difference in all-cause mortality (HR 0.91, 95% confidence interval [CI] 0.76 to 1.10, p = 0.33), stroke (HR 0.96, 95% CI 0.80 to 1.16, p = 0.70), and major/life-threatening bleeding (HR 1.05, 95% CI 0.82 to 1.35, p = 0.70) in patients that received DOAC compared with oral VKA. Risk of any bleeding was lower in the DOAC group compared with oral VKA (HR 0.83, 95% CI 0.76 to 0.91, p = 0.0001). In patients with AF, DOACs appear to be a safe alternative oral anticoagulation strategy to oral VKA after TAVI. Further randomized studies are required to confirm the role of DOACs in those patients.

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.

Antithrombotic strategies after transcatheter aortic valve implantation: A systematic review and network meta-analysis of randomized controlled trials

AIMS

Meta-analyses comparing different antithrombotic strategies were conducted to determine the optimal therapeutic regimen post transcatheter aortic valve implantation (TAVI). However, there were restricted high-quality direct comparisons across the different antithrombotic therapeutic regimens. We sought to explore the safety and efficacy of different antithrombotic therapy strategies after TAVI using network meta-analyses of randomized controlled trials (RCTs).

METHODS

We searched CENTRAL, PubMed, Embase and Medline through August 2021 for RCTs that directly compared different antithrombotic schemes in adults who had undergone TAVI. We conducted a pairwise and network meta-analysis measuring all-cause mortality, stroke, myocardial infarction, all bleeding and life-threatening or major bleeding events. The surface under the cumulative ranking (SUCRA) curve was estimated to rank the therapies. We evaluated the risk of bias and graded the quality of the evidence using established methods.

RESULTS

Six RCTs of 2824 patients who underwent TAVI were analysed. The risk of all bleeding [relative risk (RR) 1.88 (1.34-2.64)] and life-threatening or major bleeding [RR 2.03 (1.27-3.24)] was significantly higher for dual antiplatelet therapy (DAPT) than single antiplatelet therapy (SAPT), whereas there was no significant difference in the risk of all-cause mortality [RR 1.01 (0.61-1.68)] between DAPT and SAPT. Oral anticoagulant (OAC) + SAPT (OACSAPT) had significantly higher rates of all bleeding and life-threatening or major bleeding events compared with SAPT ([RR 3.46 (2.23-5.36)], [RR 2.86 (1.50-5.45)]). The risk of all-cause mortality [RR 1.72 (1.14-2.59)] and all bleeding [RR 1.84 (1.38-2.44)] were significantly higher for OACSAPT than DAPT, whereas there was no significant difference in the risk of life-threatening or major bleeding events [RR 1.41 (0.89-2.23)] between DAPT and OACSAPT. There was no significant difference in stroke or myocardial infarction among the different antithrombotic strategies (SAPT, DAPT and OACSAPT). Additionally, patients receiving OACSAPT had the highest risks for all-cause mortality (SUCRA 3.5%) and life-threatening or major bleeding (SUCRA 2.3%). SAPT seemed to be superior to DAPT in terms of all-cause mortality (SUCRA SAPT: 76.7%, DAPT: 69.8%) and stroke (SUCRA 69.6%, 59.7%).

CONCLUSIONS

Except for OACSAPT having a higher all-cause mortality than DAPT, patients who underwent TAVI had similar all-cause mortality, stroke and myocardial infarction rates among different antithrombotic regimens. Patients on SAPT had a significantly lower bleeding risk than those on DAPT and OACSAPT. Our study indicates that SAPT is the preferred therapeutic strategy when there is no indication for OAC or DAPT. Furthermore, the application of OACSAPT was ranked the worst among all antithrombotic regimens and should be averted due to an increased risk of all-cause mortality and all bleeding.

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.

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.

Anticoagulation With or Without Antiplatelet Therapy Following Transcatheter Aortic Valve Replacement for Patients With Atrial Fibrillation: A Meta-Analysis

BACKGROUND

Although current guidelines recommend oral anticoagulants (OAC) with or without antiplatelet therapy (APT) following transcatheter aortic valve replacement (TVAR) in patients with an indication for long-term anticoagulation therapy, the optimal antithrombotic strategy remains unknown in these population. Herein, we conducted a meta-analysis comparing the outcome of OAC alone versus OAC with APT following TAVR in patients with atrial fibrillation (AF).

METHODS

MEDLINE and EMBASE were searched through May 2020 to identify clinical trials that investigated OAC alone versus OAC with APT following TAVR in patients with AF. From each study, we extracted the hazard ratios (HRs) or risk ratios of major or life threatening bleeding, stroke, all-cause mortality and cardiovascular mortality.

RESULTS

1 randomized controlled trial and 3 observational studies were identified, which enrolled a total of 2032 patients with AF who underwent TAVR assigned to the OAC group (n = 722) or OAC with APT group (n = 1310). Pooled analyses demonstrated the rate of major or life threatening bleeding was significantly lower in the OAC group compared to the OAC with APT group (HR [95% Confidence Interval [CI] = 0.54 [0.38-0.77], P = .0006]). However, the rate of stroke was similar in both groups (HR [95% CI] = 1.22 [0.80-1.87], P = .36). All-cause and cardiovascular mortalities were also similar in both groups.

CONCLUSIONS

We observed that OAC with APT following TAVR in patients with AF increased the risk of bleeding compared to OAC alone without decreasing the risk of stroke.