August 30, 2020
POPular TAVI Study Compares Antithrombotic Strategies After Valve Replacement
August 30, 2020—Findings from the POPular TAVI trial challenge current guideline recommendations on antiplatelet treatment after transcatheter aortic valve replacement (TAVR) in patients not taking oral anticoagulation, according to the European Society of Cardiology (ESC).
The POPular TAVI trial investigated the optimal antithrombotic therapy in two cohorts. Cohort A included patients not on oral anticoagulants and excluded patients who had undergone coronary artery stenting using a drug-eluting stent within 3 months or using a bare-metal stent within 1 month of undergoing TAVR. The findings from cohort A were presented in a Hot Line session at ESC Congress 2020—The Digital Experience, held online as a virtual event August 29 to September 1, 2020.
Results from cohort B of patients on chronic oral anticoagulation have been published. The cohorts were powered separately for the study outcomes.
The study’s coordinating investigator is Jorn Brouwer, MD, of St. Antonius Hospital in Nieuwegein, the Netherlands. In the ESC press release, Dr. Brouwer commented, “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.”
Dr. Brouwer concluded, “The trial shows that aspirin alone should be used in patients undergoing TAVR who are not on oral anticoagulation and have not recently undergone coronary stenting.”
As summarized in the ESC announcement, cohort A was composed of 665 patients without an indication for oral anticoagulation who were randomly allocated to aspirin alone (331 patients) or aspirin with 3 months of clopidogrel (334 patients).
The study tested the hypothesis that aspirin alone compared to aspirin with clopidogrel for 3 months would reduce the rate of bleeding at 1 year. The investigators found that aspirin alone resulted in a significantly lower incidence of bleeding compared to aspirin with clopidogrel at 1 year.
The coprimary outcomes were all bleeding (procedural and nonprocedural) and nonprocedural bleeding.
- All bleeding occurred in 50 patients (15.1%) receiving aspirin alone versus 89 patients (26.6%) receiving aspirin with clopidogrel (risk ratio [RR] 0.57; 95% CI, 0.42-0.77; P = .001).
- Nonprocedural bleeding occurred in 50 patients (15.1%) receiving aspirin alone and 83 patients (24.9%) receiving aspirin with clopidogrel (RR 0.61; 95% CI, 0.44-0.83; P = .005).
In addition, two secondary outcomes were used to test the hypothesis that aspirin alone would be noninferior to aspirin with clopidogrel at 1 year. The first examined bleeding and thromboembolic events and was a composite of cardiovascular mortality, nonprocedural bleeding, all-cause stroke, or myocardial infarction. The second examined only thromboembolic events and was a combination of cardiovascular mortality, ischemic stroke, or myocardial infarction.
- For the secondary outcome on bleeding and thromboembolic events, aspirin alone was superior compared to combined therapy. The outcome occurred in 76 patients (23%) receiving aspirin alone compared to 104 patients (31.1%) receiving aspirin with clopidogrel (difference −8.2 percentage points; 95% CI for noninferiority, −14.9 to −1.5; P < .001; RR, 0.74; 95% CI for superiority, 0.57-0.95; P = .04).
- For the secondary outcome on thromboembolic events, events occurred in 32 patients (9.7%) receiving aspirin alone compared to 33 patients (9.9%) receiving aspirin with clopidogrel (difference −0.2 percentage points; 95% CI for noninferiority, −4.7 to 4.3; P = .004).