One month ago we shared a meta-analysis stating aspirin (ASA) as the best antiplatelet following TAVR vs. 3 to 6 dual antiplatelet therapy suggested by guidelines.
At that time, guideline recommendations appeared obsolete. Several studies had started to support ASA monotherapy as the best antiaggregation scheme after TAVR. However, in the light of this new study published in Circulation, now aspirin does not appear to be the definitive solution either.
This is relevant because, so far, no study had questioned the use of aspirin in this scenario.
All things considered, and the latest publication not necessarily translates into correct information. What this study clearly shows is the existing disagreement over the best antiaggregation scheme following TAVR.
The OCEAN-TAVI registry included patients undergoing TAVR between 2013 and 2017 in several centers in Japan. The registry identified 829 cases discharged with aspirin (100 mg) or clopidogrel (75 mg).
These were stratified according to anticoagulation need. Propensity score was used to adjust baseline characteristics between the ASA and the Clopidogrel groups.
Read also: Dual Antiplatelet Therapy and TAVR: Obsolete Guidelines.
Primary end point was all cause death, cardiovascular death, life threatening bleeding and major bleeding within 2 years after procedure.
After adjusting, researchers were left with 196 patients (98 ASA and 98 clopidogrel) not requiring anticoagulation and 314 patients (157 ASA and 157 clopidogrel) requiring anticoagulation, especially because of atrial fibrillation.
All-cause mortality resulted similar between patients requiring and not requiring anticoagulation, regardless medication (with anticoagulation: aspirin 17.5% vs clopidogrel 11.1%; p=0.07. Without anticoagulation: aspirin 29.6% vs clopidogrel 20.1%; p=0.15).
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These findings completely changed when looking at cardiovascular mortality. For this end point, clopidogrel got a clear advantage at 2-year followup, regardless anticoagulation requirement (with anticoagulation: aspirin 8.5% vs clopidogrel 2.7%; p=0.03. Without: aspirin 18% vs clopidogrel 5.2%; p=0.02).
Conclusion
According to this study, clopidogrel monotherapy is associated with lower cardiovascular mortality compared against aspirin monotherapy at 2-year follow up, after TAVR, regardless anticoagulation requirement.
Original Title: Aspirin Versus Clopidogrel as Single Antithrombotic Therapy After Transcatheter Aortic Valve Replacement: Insight From the OCEAN-TAVI Registry.
Reference: Yusuke Kobari et al. Circ Cardiovasc Interv. 2021 May;14(5):e010097. doi: 10.1161/CIRCINTERVENTIONS.120.010097.
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