Anticoagulation with or without Clopidogrel after Transcatheter Aortic-Valve Implantation

Trial Reference
Nijenhuis VJ, Brouwer J, Delewi R, et al. Anticoagulation with or without Clopidogrel after Transcatheter Aortic-Valve Implantation. N Engl J Med. 2020 Apr 30;382(18):1696-1707. doi: 10.1056/NEJMoa1915152.
Expert Comment
Augusto Gallino
University of Zurich, Switzerland

BACKGROUND

The randomized open-labeled study (POPular TAVI trial, Cohort A) by Nijenhuis et al questioned the paradigm of the a prolonged double antiaggregation (DAPT) during the first 3-6 months in patients undergoing TAVI who do not need long-term use of oral anticoagulation. In a well structured approach they used TAVI outcome according VARC classification and where due to limitations of the definition of VARC and BARC bleeding score, bleeding at the TAVI puncture site was not defined as BARC type 4 but was counted separately and included in the outcome of non–procedure-related bleeding. The authors found that bleeding was high significantly more prevalent in the group patients undergoing DAPT when compared to aspirin and this holds true for minor or severe bleeding. Aspirin was noninferior, but not superior to DAPT with respect to thromboembolic events including myocardial infarction and ischemic strokes

COMMENT

Transcatheter aortic-valve implantation (TAVI) is a growing interventional procedure that has gained an established role in the treatment of significant symptomatic aortic valve stenosis. Guidelines recommend dual Aspirin and Clopidogrel for 3-6 months after a TAVI procedure mainly based on histopathology and clinical case report observations and computer tomography (CT) studies of the implanted valve reporting high risk of thrombosis and of thromboembolism before re-endothelialization of the valve is completed. However, the through population’s age consists of a majority of elderly patients who are frequently polymorbid and present concomitant diseases like gastrointestinal angiodysplasia, von Wildebrand factor deficiency and polypharmacy associated with bleeding.

The study has several limitations among them the open-label approach even taking into account that events were adjudicated by a clinical-events committee. The study was powered for the composite of hemorrhagic or thromboembolic events, and not focused on thromboembolism; the incidence of thromboembolic events were numerically higher but not statistically significant. Finally the trial did not include focused CT evaluation for the detection of subclinical valve thrombosis, being the main outcome of the study a clinical endpoint.

This trial together with the accompanying twin article also published this year in the NEJM in patients needing long-term anticoagulation and undergoing TAVI, has the merit to challenge the paradigm of DAPT strategy after a TAVI and opens a new avenue which indicates how post TAVI antiplatelet regimen should probably be better individualized for each patient, well balancing the bleeding and thrombotic risk. So far larger prospective randomized trials with larger number of patients are not completed we have to cope with the actual guidelines.

References

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  8. Nijenhuis V.J., Brouwer J., Delewi R., et al. N Engl J Med 2020; 382:1696-170.

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