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.