Two AF cases — and my changing view of AF

I receive many emails about AF. I don’t often answer them because it is bad practice to doctor without seeing the person. Recently, however, I received a note with more general questions. The sender suggested I could use the response as a blog post. The reason I am posting these two cases along with my response is that my views on AF are changing. I am in the process of putting these global thoughts on AF together as a more general update, but these cases are a start.

Here is the email from a reader: (a doctor).

Dear John,

What would you recommend?

My med school roommate and I are 69 years old and in good health, normal BMIs, non-smokers, social drinkers. We both exercise almost daily. He takes something for mild hypertension. I’m on no meds.

He has had 3 episodes of PAF in his life–one in 1984 and two in the last few months. They all converted spontaneously to NSR. His doctor worked him up fully including an echo. His heart is structurally sound and no clots were noted. He has been strongly advised to start taking Coumadin or Pradaxa.

I have also had 3 episodes–one at age 26 which reverted to sinus after one dose of quinidine (I am old) and two about 6 months ago a couple of days apart which disappeared in about 12 hours after a good night’s sleep. I did not see a doctor about this. I had a normal echo 10 months ago because a routine EKG done as part of a preop eval for shoulder surgery showed nonspecific changes and I didn’t have a previous EKG to compare it to.

I don’t know if you saw this (http://thehealthcareblog.com/blog/2014/02/01/why-your-a-fib-diagnosis-may-not-be-as-bad-as-you-think-it-is/). It’s not much help.

What would you recommend if we were your patients?

Personally, I have seen so many complications with anticoagulation, especially Coumadin, that I am reluctant to take anything. I should mention that my father died of a stroke at age 76, but he was a heavy cigarette smoker all his life. He did not have A fib.

My response:

Sorry about the AF. (As an AF patient myself, I understand the frustration.)

A few things about treating AF.

First the complications:

The most important complication from AF is stroke—as it is often life-altering, or ending, the former is sometimes worse. The risk of stroke is surprisingly not related to the “amount” of AF a patient has. I often hear, from other physicians, that patients don’t have that much AF so stroke risk is low. There is evidence to support that this intuition is incorrect. Paroxysmal AF patients have as much risk as persistent AF patients.

The risk of stroke depends on the company AF keeps. We use the CHADS-VASC score, which considers the presence of CHF, HTN, AGE > 75 (2 points), Diabetes, Prior stroke/TIA (2 points), Vascular disease, Age >65  and Sex category (females  get 1 point).

Thus, your CHADS-VASC score is 1 and this confers a 1.3% annual stroke risk with no warfarin or other anticoagulants. The stroke risk on warfarin is not much lower — 0.5-6%, but the average risk of bleeding is in the range of 3%. Most guidelines, therefore, do not recommend anticoagulation. That’s a patient level decision though because there is a very small absolute risk reduction in stroke with anticoagulants. An important note is that there is no benefit from aspirin. And my view of the new anticoagulant drugs is that they are 99.3% similar in efficacy and safety but more than 100 times the cost.

Your friend’s risk score is higher because of hypertension. He gets a CHADSVASC of 2, which increases his annual stroke risk to 2.3-2.9% without drug and then 1% on warfarin. (Same 3% risk of bleeding.) His risk reduction is double yours, in the range of 1.5%—or a NNT of about 66. (A note on bleeding risk is that it’s not zero without warfarin; it’s about 1% in the general population but varies on other factors. Patients bleed without taking anticoagulants.)

Recall that almost all patients with bleeding leave the hospital the same person they came in as. That’s not often the case with strokes. ICH (intracranial hemorrhage) is the exception; thankfully, it is uncommon. A quick sidebar on ICH: the last two patients I saw with ICH probably had hemorrhagic transformation of ischemic stroke rather than a primary brain bleed. Meaning, if they had not had a stroke in the first place, they would not have bled into the brain.

Those are the odds that I quote. The risk of stroke and bleeding with different levels of CHADSVASC scores, on or off warfarin, come from population-level data, and have been confirmed in analyses of clinical trials.

Now onto the AF itself:

As for treating the episodes and having AF, it is now clear to me that AF is rarely a primary disease. Meaning, I think AF occurs because of perturbations of other health issues. This may sound pseudo-science-like but I think AF occurs when homeostasis of the mind, body or soul is disturbed. Think brain-heart connection via neural pathways. Poor sleep (?OSA), alcohol, stress, obesity, hypertension, caffeine, travel, worry. recent bronchitis, injury, surgery, etc are all common associated issues. And some individuals are clearly more susceptible than others, likely due to genetic variations in cell functions. Yes, of course, there are those patients who develop AF as a form of a focal tachycardia without any other health issues, a fluke if you will, but these are the small minority.

Research on the role of lifestyle and arrhythmia is beginning to show that AF may be unnecessary.

I like your treatments, which include prn (as needed) things. In your case, time and sleep–beautifully effective strategies for many medical problems. When I use anti-arrhythmic drugs, I often prescribe them as prn therapies so patients aren’t exposed to the drug on days they are not having the episodes. If a patient has one AF episode per month, that’s 29/30 days  she has no episodes. I find focusing on the positive is good for AF patients, as it sometimes helps them avoid over-treatment.

The problem (bias) I have, and other cardiologists too, is that we see a skewed population of AF patients. I, for one, see about 1 AF patient per year with a disabling stroke and a CHADSVASC of 0 or 1. We see the 1%, in other words.

I never “strongly advise” low-risk patients to do anything. Instead, I strongly advise them their statistics. People feel differently about NNTs of > 50 or 100.

Another bias of mine: I have little fear of warfarin. If my AF came back, I would get a home monitor and never have an INR out of range. We now do pacemaker and ICD surgery (and AF ablation with transeptal heart puncture) with patients fully anti-coagulated. There was even a NEJM study showing lower complications with device surgery when patients were left on warfarin.

I realize the anticoagulation viewpoint of other MDs is different from mine.

Hope this helps.

JMM