TAVR presented at #JPM2020 by CEO, page-24

With regards to question 1
- the existing scrunched up native valve actually helps anchor the new transcatheter catheter in place.
Paradoxically, the more calcified the native tissue is, the greater the anchoring effect and it reduces the chances of complications such as valve migration.
- For those patients whose stenosed valves didn't have too much calcific tissue to start with, surgeons/interventionalists may often have to "oversize" or choose a large sized prosthesis to make up for the lost effect of anchoring of the calcification.
- this might sound very non-precise and non-scientific, but do remember for all TAVR procedures, patients have intraoperative TEEs done live to ensure that the hemodynamics of the newly placed valves as well as positioning is most optimal
- The "post-installation" source of nasties i.e calcification of the new installed valves is the achilles heel of such existing technologies on the market. ADAPT is here to directly address this issue

With regards to question 2
- the decision for optimal anticoagulation is complex and there is still ongoing differences between American and European guidelines
- also remember that in pts with aortic stenosis, chances are they have many other concurrent comorbidities
- it seems now to depend on what other conditions the patient has and their baseline risk factor profile (e.g. Chadsvasc score)
- ie if they need anticoagulation for other concurrent conditions such as AF, then a factor Xa inhibitor / NOAC would be considered
- whereas if no other concurrent comorbidities requiring anticoagulation, then perhaps an aspirin-only approach could be considered

With regards to "Is there any way of predicting the likelihood of clotting from test measuring the valve characteristics?"
- answer is yes but no. Yes being people have been using a marker called Activated clotting time (ACT) during the procedure which is a marker of how the thin the blood is intraoperatively with heparin. If they have had /already on anticoagulation, then INR is typically used.
- the reason I say no is because, there isn't clear guidelines on what the optimal ACT target should be - whether its >200s, >250s or even >300 seconds...
- basically watch this space for anticoagulation for TAVR patients!