Algorithm for OAC post ablation

As everyone knows, being in a-fib requires taking oral anti-coagulant (OAC) to reduce the likelihood of thrombus (clot) forming in the left atrium which would create a source for embolus to the brain resulting in a catastrophic stroke. There are scoring systems to quantify the risk/reward of taking them, such as the CHAD-Vasc score, etc. but in general the benefit far outweighs the risk.

After an ablation procedure, the patient adds an additional risk for thrombus in the left atrium, and that is the risk of clot forming at the burn-sites around the pulmonary veins. These sites represent damaged endocardium and cells adhere to those areas with clot a true risk. This is an additional risk above and beyond the risk associated with the a-fib itself.

If one is clearly in normal sinus rhythm (NSR) post ablation, there is some rather arbitrary point in time when one no longer needs OAC.....no a-fib equals no risk of thrombus (there is of course the possibility of 'silent' a-fib during the night etc which carries the same risk of thrombus as if you knew about it, so being in NSR is a huge assumption). But post ablation, no matter the heart rhythm one is in, they MUST be on OAC until the healing of the endocardial tissue has been completed.

I'd love to know what the 'experts' think about what that time period is. Many think it to be completely healed at 2 weeks, others say 1 month. I have searched for data on this topic without success.

I haven't searched the literature on this but out of six ablations I was kept on an OAC for at least three months for all except one of them. After the one exception I was only kept on an OAC for one month, but that ablation involved only the right atrium so very low stroke risk. From what I've seen from others, three months is almost universal, at least in the US.

Carey-what about pvc’s? It is an arrhythmia. Isn’t the heart vibrating like af when someone gets a run of pvc that are on off all day? Same 3 months?

Last night after my multaq and magnesium I had such violent (high hr and syncope) pvc that would not go away. I have to take a Kardia reading as part of my ep Kardia program and the readings kept saying possible AF but it’s a Kardia software interpretation and not Natale. I repeated the readings but got noise interpretation but the reading 6 lead strips had no artifact. Even my BP cut provides by Kardia kept flashing possible af. I was not in AF. I took an Afibalert reading. My hr was steadily bouncing from the same numbers - 38 and 125.

That said, honestly after my 3 months blanking period, I would not know the difference between af and pvc to know if I should tell my ep so he could resume Eliquis or to get cardio converted if af to lower my AF burden.

PVCs don't require anticoagulants. Just because something is technically called an arrhythmia doesn't mean it creates a stroke risk. Most arrhythmias don't. The atria aren't quivering and pumping ineffectively like they are in afib, so the risk of blood pooling in the left atrium and forming clots isn't present. I've seen several of your ECGs and although they showed bigeminal PVCs, they were all otherwise a normal rhythm. None of them showed afib nor did they bounce around between rates in the 30s and 120s. I wouldn't trust the Afibalert's readings if it's telling you that.

Although the Kardia is likely to label a recording with lots of PACs or PVCs as "possible afib," the recording itself will be obvious to your EP. Just take a recording and email it to him and let him decide. But having had an ablation by Natale, it's unlikely you'll experience afib again anytime soon.

Carey,
I know how long they recommend OAC post-ablation, but their reasoning is related to the certainty that you are no longer in AF. My question relates only to the incremental increase related to the burn-sites.Most intimal healing of vessels occurs within 2 weeks, and I assume the endocardium would be about the same.

Are you talking about PVI only, or full Ablation? Also whether its RF or Cryo would make a difference in the answer.

That said, are you taking into account Atrial Stunning and regaining Atrial Contractibility? Even just after a regular Cardioversion from AFIB >48 hours, the standard requirement is Anti-Coagulation for 4 weeks. People can still have Clot formation post ECV, while maintaining NSR. This is because the Atria are "Stunned" after being in AFIB, and although usually less, it can take up to a month to regain full contractibility. It probably takes longer than that to regain contractibilty in a Atria that has just been Ablated. There should be studies on this, but I am not planning of getting an Ablation, so I will not research it, but I have read in the past, that often, particularly if multiple Ablations were performed, that the Atria do not ever completely regain their full contractile strength.

Secondly, how would you verify that the Endocardial Tissue is indeed healed at 2 weeks, even if you found research to show this is probably the case? This is EP questioning, and you would probably get differing opinions even from the Ablationists themselves. Most all Dr's would want to maintain an OAC, just to be sure, and for liability protection.



Edited 2 time(s). Last edit at 10/20/2019 02:35AM by The Anti-Fib.

Anti-Afib,
Any procedure involving the LA subjects the endocardium to damage, intentional (ablation) or unintentional (LA 'stunning'). My question about the healing time for endocardium is purely to gather other opinions, since the only way to determine the time of healing would be at autopsy. Perhaps there is some scarce data on this, but I have not found it. Also there would not likely be any difference in how the damage was done, whether by RF or cryo...damage is the sine-quo-non for the formation of thrombus, not the method of damage.

My analogy to endothelium (lining of blood vessels) is simply because it is the only similar cell-lining about which we do have good data about healing time. For example, post endarterectomy of vessels (carotid, femoral artery etc) we know that healing is complete at around 2 weeks.

What I am trying to get away from is the nearly automatic assumption that conventional habits are based on conclusive data. Such is not the case, as precedents and 'standard of care' can override data and evidence very often. I'm simply trying to gain a better understanding of the "why's" for what has become standard behaviors.