The combination of oral anticoagulation and the antiplatelet drug clopidogrel increases the risk of bleeding after transcatheter aortic valve implantation (TAVI) compared with oral anticoagulation alone, according to the results of the POPular TAVI trial cohort B, which were presented at the ACC Scientific Sessions 2020.

Patients undergoing TAVI often have atrial fibrillation and, for those with an indication, current clinical guidelines recommend oral anticoagulation with or without aspirin or clopidogrel. The addition of an antiplatelet agent is intended to reduce the risk of thrombotic events but might be outweighed by an increase in bleeding.

POPular TAVI cohort B included patients undergoing TAVI with a pre-existing indication for anticoagulation (cohort A includes those without an indication for anticoagulation and has not yet been completed). Patients receiving oral anticoagulation were randomly assigned to 3 months with or without clopidogrel therapy after TAVI and were followed up for 12 months. Bleeding occurred in 21.7% of the 157 patients receiving oral anticoagulation therapy alone compared with 34.6% of the 156 patients receiving oral anticoagulation plus clopidogrel therapy (risk ratio (RR) 0.63, 95% CI 0.43–0.90, P = 0.01). Non-procedure-related bleeding (which included bleeding at the puncture site) occurred in 21.7% and 34.0% of patients in each group, respectively (RR 0.64, 95% CI 0.44–0.92, P = 0.02). A secondary end point of myocardial infarction, ischaemic stroke or death from cardiovascular causes occurred in 13.4% and 17.3% of patients in each group, respectively, which met the prespecified criteria for non-inferiority of no clopidogrel therapy.

“The ideal would be an anticoagulant regimen that minimizes the risk of death, stroke, myocardial infarction or permanent disability, whether resulting from thrombosis or bleeding,” comments Frederick Fiet in an accompanying editorial in NEJM. “These are the events that matter most to patients.”