Looking at what I think was the seminal study, I am not confident the results are generalizable to many candidates.
Most subjects (85%) in the trial were not in permanent atrial fib and also had relatively low risk scores. And, critically, the majority of patients enrolled had normal LV function. Again, patient populations vary, but this doesn’t sound like most atrial fib patients I see.
Sorry, it’s fellowship interview season and then I was off site, but I’ll get back to you about the use of OAC after ablation.
As far as Watchman, any invasive procedure is going to carry some risks, and in the case of the Watchman, they poke a hole through the wall dividing the atria to get to it. There’s a risk of bleeding into the pericardial space as well as the risk that the device does not completely endothelialize or completely occlude the left atrial appendage leading to further thrombosis risk. It may be something like the TAVR/TAVI procedure which is now as good as if not better than a surgical aortic valve replacement, but that took many years and clinical trials and started in the highest of surgical risk patients before it got to that point earlier this year. It’s implanting an irretrievable device into the heart so there’s a lot of hurdles it has to clear before it could be considered a viable alternative to the much better studied oral anticoagulant therapies.
So the guidelines AHA 2012, HRS 2012 recommend continuing anticoag post-ablation per risk score because of the risk for asymptomatic recurrence. CABANA 2019 was a RCT which looked at ablation vs chemical antiarrhythmics and showed no difference in stroke risk. There were some big problems with the study, primarily due to the hefty crossover, but it’s the most recent big study that dealt with the topic.