Cohort A evaluated aspirin alone vs. aspirin plus clopidogrel in patients without an indication for oral anticoagulation (OAC), while cohort B evaluated OAC alone vs. OAC plus clopidogrel in patients with an indication for OAC. Results from cohort B were recently published and the key finding was that the incidence of serious bleeding was lower with OAC alone than with OAC plus 3 months of clopidogrel.1
Today, results from cohort A were presented as a Hot Line at ESC Congress 2020 by Coordinating Investigator, Doctor Jorn Brouwer (St. Antonius Hospital, Nieuwegein, the Netherlands). Cohort A compared aspirin alone vs. aspirin plus 3 months of clopidogrel in 665 patients without an indication for OAC. Patients who had undergone drug-eluting stenting within 3 months or bare metal stent within 1 month prior to TAVI were excluded.
The co-primary outcomes were all bleeding (procedural and non-procedural) and non-procedural bleeding and, in both cases, aspirin alone resulted in a significantly lower bleeding compared with aspirin plus clopidogrel at 1 year. All bleeding occurred in 15.1% of patients receiving aspirin alone vs. 26.6% of patients receiving aspirin plus clopidogrel (risk ratio [RR] 0.57; 95% confidence interval [CI] 0.42 to 0.77; p=0.001). Non-procedural bleeding occurred in 15.1% of patients receiving aspirin alone and 24.9% receiving aspirin plus clopidogrel (RR 0.61; 95% CI 0.44 to 0.83; p=0.005).
For a secondary outcome composite of bleeding and thromboembolic events (cardiovascular mortality, non-procedural bleeding, all-cause stroke or myocardial infarction), aspirin alone was superior compared with combined therapy (23.0% vs. 31.1%; difference –8.2 percentage points; 95% CI for noninferiority –14.9 to –1.5; p<0.001; RR 0.74; 95% CI for superiority 0.57 to 0.95; p=0.04). The secondary outcome composite of thromboembolic events only (cardiovascular mortality, ischaemic stroke or myocardial infarction) was noninferior between the groups, occurring in 9.7% of patients receiving aspirin alone compared with 9.9% of patients receiving aspirin plus clopidogrel (difference –0.2 percentage points; 95% CI for noninferiority –4.7 to 4.3; p=0.004).
Summarising the findings, Dr. Brouwer said, “Aspirin alone as compared to aspirin with clopidogrel reduced the bleeding rate significantly, with an absolute reduction of more than 10%. At the same time, aspirin alone compared to aspirin with clopidogrel did not result in an increase in thromboembolic events as captured in the secondary outcomes.” He concluded, “The trial shows that aspirin alone should be used in patients undergoing TAVI who are not on OAC and have not recently undergone coronary stenting.”