Atrial Fibrillation and Pacemakers: Can Both be Coded?

Dysrhythmias like complete heart block, AF, and SSS all fall into HCC 96, with a risk adjustment factor of 0.268.

Our listeners and readers ask the most interesting questions! One named Dena recently wrote me and said, “I am an HCC coder, and there is a hot debate about coding atrial fibrillation after pacemaker implant. Some say because the PCP has to prescribe medications, they should still be able to code afib. Some say once the pacemaker is placed, they should only code the pacemaker.” She then asked my opinion.

I have a greater appreciation for this after my father had a recent admission for a heart rate of 27. Due to a prior pacemaker infection with sepsis, the cardiologist opted to implant a most remarkable leadless micra pacemaker, even though his patient had already popped back into his usual atrial fibrillation at a rate of 105.

Atrial fibrillation (AF) is the most common cardiac dysrhythmia, afflicting between 2 and 6 million people in the United States. Changes in the anatomy and electrophysiology of the smaller upper chambers of the heart, or atria, cause chaotic electrical impulses, which are unpredictably propagated to the lower chambers, or ventricles, causing irregular contraction of the heart muscle. AF often results in a rapid heartbeat, and the treatment is either cardioversion to a normal sinus rhythm, or rate control. Anticoagulation is often prescribed, because clots can form in the heart and be embolized to the brain, causing strokes.

Pacemakers in atrial fibrillation are most commonly placed for symptomatic bradycardia, either medication-induced or due to aging, diseased heart muscle. It is less common to insert a pacemaker for overdrive atrial pacing. The pacemaker does not directly treat atrial fibrillation, and it certainly does not cure or resolve it.

There are reasons why we code. We translate the acute patient encounter into codes to determine reimbursement. Complete and accurate coding helps us judge the quality of care provided.

Population health prospective risk adjustment allots resources according to predicted resource utilization. Research and epidemiological analysis depend on comprehensive capture of conditions (shameless plug for the social determinants of health, or SDoH, here). We need to code conditions that are present and relevant.

I think the confusion and conflicting practice stems from past Coding Clinic rulings regarding sick sinus syndrome (SSS), an umbrella term for abnormal heart rhythms caused by malfunction of the sinus node, or the heart’s natural pacemaker. AF with a slow ventricular response is sometimes included in this grouping, although my father’s electrophysiologist says this isn’t really accurate, because the sinus node is not functioning in atrial fibrillation.

Historically, the advice of Coding Clinic, stemming back to 1993, was that once a pacemaker was placed for SSS, you only coded the pacemaker’s presence. This advice was updated on page 33 of the edition issued for the first quarter of 2019, with the guidance that SSS is considered to still be present and is a legitimate, reportable chronic condition. The Coding Clinic includes “other significant heart rhythm abnormality” in its recommendations.

Let’s think about this together.

If a patient has an arthritic right hip and undergoes a hip replacement, after the surgery, they no longer have that arthritic hip, M16.11; they have a replaced hip joint, Z96.641. They may still have osteoarthritis elsewhere, but the arthritic hip has been eliminated.

If a patient has an episode of sudden cardiac arrest from which they are resuscitated, and has an AICD implanted, they would carry a diagnosis of Z86.74, Personal history of sudden cardiac arrest and Z95.810, Presence of automatic cardiac defibrillator. They are not in a persistent state of cardiac arrest; it is historical.

If a patient has AF with a slow ventricular response, a pacemaker is addressing the pauses or bradycardia, the resultant symptoms or the risk of a nine-second asystole – like my father had. It is not resolving or eradicating the atrial fibrillation. The AF is still present, underlying the paced rhythm. The bradycardia and pacemaker firing could also be only intermittent, like in my father’s situation. In his case, his post-discharge pacemaker check showed it was only operating 4 percent of the time. If the pacemaker were to malfunction or to be turned off, the observed rhythm would be AF in such a patient. They may even remain on anticoagulation or medication for rate control. AF is a valid diagnosis.

What if a patient undergoes a successful maze procedure for AF, reverts to normal sinus rhythm, and stays in sinus? That would be curative. You could capture personal history codes, but the patient no longer has a current cardiac condition.

I appreciate that HCC coders do not want to look like they are cooking the books and inflating the risk adjustment score. Dysrhythmias like complete heart block, AF, and SSS all fall into HCC 96, with a risk adjustment factor of 0.268.

Dena, the patient, and the provider are entitled to it. Go for it.

Programming Note: Dr. Erica Remer is the co-host of Talk Ten Tuesdays. Listen to her today and every Tuesday during the live edition of Talk Ten Tuesdays, 10 a.m. EDT.