HALT After TAVR: Searching the Bases, Finding the Cusp

Nührenberg et al. (1) reported that hypoattenuated leaflet thickening (HALT) after transcatheter aortic valve replacement (TAVR) is not associated with pharmacodynamic response to clopidogrel. HALT and subclinical leaflet thrombosis are an issue in patients with TAVR. It has already been reported that anticoagulation is superior to antiplatelet medication in prevention of HALT/subclinical leaflet thrombosis (2). This goes in line with findings of the present study by Nührenberg et al. (1), who reported that HALT was significantly lower in patients with oral anticoagulation. However, the GALILEO trial (Global Study Comparing a rivAroxaban-based Antithrombotic Strategy to an antipLatelet-based Strategy After Transcatheter aortIc vaLve rEplacement to Optimize Clinical Outcomes) that investigated a combination of “medium-dose” anticoagulation and aspirin as compared with aspirin plus clopidogrel was terminated early due to high bleeding and ischemic events in the “medium-dose” anticoagulation group. Therefore, this combination seems not to be favorable in patients with TAVR. The basis of most tested regimes in patients with TAVR is aspirin. It is known that pharmacodynamic response to aspirin varies substantially between individuals. It was recently demonstrated that aspirin only exerts its cardiovascular protection in patients with a body weight below 70 kg (3). Besides body weight, multiple other factors have been described to impair aspirin antiplatelet effects (4). We have shown that aspirin antiplatelet effects are impaired in about 20% of patients with TAVR (5). If there is an association between subclinical leaflet thrombosis/HALT and pharmacodynamic response to aspirin, it is completely unknown. Unfortunately, aspirin antiplatelet effects were not addressed in the present study by Nührenberg et al. (1). It would be highly interesting if impaired pharmacodynamic response to aspirin is associated with HALT/subclinical leaflet thrombosis. *Amin Polzin, MDy Verena Veulemans, MDy Lisa Dannenberg, MD Malte Kelm, MD Tobias Zeus, MD *Department of Cardiology, Pulmonology, and Vascular Medicine Medical Faculty of the Heinrich Heine University Düsseldorf Cardiovascular Research Institute Düsseldorf (CARID) Moorenstrasse 5 40225 Düsseldorf Germany E-mail: amin.polzin@med.uni-duesseldorf.de