Say It Isn't So. . . . In the Treatment of Typical Atrial Flutter, Less May Not Be More

November 22, 2013

I need help. Here is a common case that causes me great consternation. It is one that brings two worthy philosophies into the ring. In one corner is the ever-virtuous minimally disruptive philosophy. In the other corner is pragmatism.

A  65-year-old man with a history of obesity and hypertension complains of sustained tachycardia, fatigue, and exertional dyspnea for the past week. The 12-lead ECG shows typical atrial flutter (AFl) with a ventricular rate of 120 bpm. Last year, he had intermittent self-terminating palpitations. A 30-day event monitor showed paroxysmal atrial fibrillation. Moderate-dose propafenone relieved his symptoms until this recent episode of atrial flutter. Stress testing showed no ischemia, and echocardiography revealed only mild left atrial dilation. He takes warfarin, propafenone, lisinopril, and metoprolol and sleeps with a CPAP machine.

What is the best treatment approach for this common problem? Is it 1) ablate the AFl and continue medical treatment for AF, or 2) ablate both AFl and AF in the index procedure?

Multiple abstracts on the last day of the American Heart Association 2013 Sessions shed light on this everyday scenario. My opinion on this matter has evolved over the past few years.

(Some assumptions: First is that atrial flutter is an arrhythmia ill-suited for medical therapy. Changing drugs is unlikely to work and may make the flutter more persistent. The second given is that cardioversion has been discussed, and the patient prefers more definitive therapy. The recurrence rate of atrial flutter after cardioversion is very high. The third assumption is that in this post we equate AFl to typical right atrial flutter and AFl ablation to cavotricuspid isthmus [CTI] ablation.)

In option 1, which I will call the "incremental" approach, we perform AFl ablation and then continue medical therapy of AF, along with intensive risk-factor modification. The main advantage of this approach is its minimally disruptive nature, and that . . .

Atrial-Flutter Ablation Is Safe:

Dr Ghanshyambhai Savani (University of Miami, FL) and colleagues presented a database analysis of 38 881 AFl ablation procedures from 2000 to 2008. They found a strikingly low complication rate of only 0.3%. This study is notable because of its large sample size and real-world cohort. What's more, an extensive evidence base supports the efficacy of right atrial flutter ablation, which approaches 100% success.

So the upside of the incremental AFl ablation approach is that it is easy, safe, and effective. Right atrial flutter can be vanquished without much disruption. The downsides of this approach were highlighted in a series of abstracts presented on the final day of AHA—namely, that atrial fibrillation often recurs after AFl ablation.

Atrial-Flutter Ablation Is Only Partial Treatment:

Dr Madhu Reddy (University of Kansas, Kansas City), along with colleagues from the Texas Cardiac Arrhythmia Institute, Austin, presented a retrospective review of 589 patients who underwent AFl ablation between 2007 and 2012. Over a mean follow-up of 31 months, 57% of patients with a preablation history of AF developed AF, while 29% of preablation patients without AF developed AF. Said another way, if a patient had both AF and AFl, there was almost a two-thirds chance of recurrent arrhythmia after AFl ablation. And almost one-third of patients with "pure" flutter had AF after AFl ablation.

These data confirm prior studies and are consistent with my experience. They are especially useful data to discuss with patients, because rhythm control of atrial fibrillation is a preference-sensitive decision. Some patients may prefer the less disruptive incremental approach, while others find the high rate of AF recurrences troublesome and desire more definitive approaches.

Ablate Both AF and Flutter Initially?

The next question in this conversation is what are the expectations of doing both AFl ablation (CTI) and AF ablation (pulmonary-vein isolation [PVI]) in the initial procedure? Here is where I have evolved a little in my tendencies. I used to favor an incremental approach in most patients. Ablate the flutter, aggressively modify risk factors, and continue AF meds was my thinking. Many patients do well with this strategy, and some are spared more extensive AF ablation. The downside of this strategy is exemplified in these abstracts:

Dr Sanghamitra Mohanty (Texas Cardiac Arrhythmia Institute), along with Italian colleagues, presented a prospective comparison of a strategy of primary AFl ablation alone vs AFl plus AF ablation in 360 patients with coexistent paroxysmal AF and AFl. There was a decided advantage for the combined initial procedure. At 20-month follow-up, hospital readmission for any reason occurred in 6.6% of those treated with a combined procedure vs 31% of those treated with AFl ablation alone. Repeat procedures were done in 28% of those who had combined ablation vs 68% who had just AFl ablation.

During the same session, Dr Jessica Voight (University of Minnesota, Minneapolis) presented a smaller study that confirmed a high risk of AF after AFl ablation but also added important information on post-AFl-ablation stroke risk. They found that 11/271 patients (4%) had a stroke after AFl ablation. Remarkably, five of the 11 had discontinued warfarin and five had recurrent AF.

My Changed Perspective for Patients With Both AF and AFl:

Two developments in electrophysiology have changed my perspective on treating atrial flutter. One is the above-noted limitations of atrial flutter ablation—recurrent AF, readmissions, and repeat procedures. The other is the growing "normality" of AF ablation. PVI is no longer an ordeal. It is a well-practiced, two-hour procedure that in our institution (like many others) has a complication of 1% or less. The vigor with which I avoid PVI has lessened.

Yes, I still think an incremental approach to atrial flutter is an option. For instance, consider the work of Dr Prash Sanders's group in Australia, published this week in JAMA . Their findings convincingly show that aggressive risk-factor modification reduces AF burden. Attention to lifestyle and risk-factor modification after AFl ablation may allow patients to avoid a more extensive left atrial ablation. This is really important—and too often underemphasized.

But the decision to choose an initially less burdensome AFl ablation brings a trade-off—namely, a higher risk of AF, readmission, or redo procedures. Consider that almost half of all PVI procedures require a redo procedure. A patient with recurrent AF after AFl ablation, therefore, may face not one more procedure, but in many cases two or more procedures.

There's a bit of irony in this dilemma. Choosing the minimally disruptive path may actually lead to more disruption. Alas, in the case of treating atrial flutter, less may not be more!

And a final factor that must be mentioned: right now, most US electrophysiologists are paid per procedure. Again, more irony. Usually fee-for-service incentivizes doctors to choose the bigger, more invasive approach. But in the case of AFl, it is the opposite. Choosing the initially minimally invasive approach may actually lead to doing more (well-compensated) procedures down the road.



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