Is rhythm control superior to rate control for AF?

on June 22, 2012  |  Permalink

Topics: Electrophysiology, Cardiovascular, Service Lines

Nicole MacMillan, Cardiovascular Roundtable

For years, the debate over rhythm control versus rate control has been hotly contested by those treating arrhythmias. A new study published this month in the Archives of Internal Medicine may exacerbate the ongoing battle by claiming that rhythm control is superior to rate control in long-term follow up.

The study, an observational analysis of 26,130 patients between 1999 and 2007, was published by Louise Pilote and colleagues from the Royal Victoria Hospital and McGill University in Montreal, Canada.

They found that four-year mortality rates for patients receiving rate control or rhythm control were roughly equivalent, echoing recent research on the same topic. However, authors of this most recent study were more interested in determining whether the two strategies were similarly effective when applied to a general population of atrial fibrillation (AF) patients with longer follow-up.

They found that mortality after the four-year mark was lower in patients treated with rhythm control.

The debate continues

Since the publication of the landmark AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial results in 2002, rate control (slowing the heart rate by blocking errant electrical signals) and rhythm control (restoring normal sinus rhythm) have been considered equally suitable treatments for AF.

Prior to the AFFIRM study, rhythm control was generally considered a superior, if riskier option compared to rate control. Today, AF treatment guidelines support the use of either strategy.  Notably, after the publication of the AFFIRM results, Pilote et. al. noted a decrease in the use of rhythm control drugs, and a tendency among providers to turn to rate control as a first-line therapy for AF.

The researchers found a 23% reduction in mortality in patients initiated to rhythm control therapy after eight years of follow-up—a significant drop compared with the small difference in mortality at four years.

While the authors do not state that rhythm control is the best option for all patients, they hope this study will incite physicians to more thoroughly consider a rhythm control strategy for AF patients, and try to maintain patients on rhythm control as long as no complications arise.

This research does not provide conclusive evidence in favor of a universal rhythm control strategy, but rather adds fuel to the fire of the ongoing debate.

In an accompanying editorial, a team from the University of California, San Francisco, questioned whether observational data can overrule randomized trial results. The large-scale randomized trials, such as AFFIRM, have immeasurably stated that both therapies are acceptable for AF patients.

More research on this topic is certainly necessary, but for the time being, Pilote et. al. claim their results suggest that rhythm control therapy may be optimal in AF patients who tolerate and see benefit from antiarrhythmic drugs.

Another debate: antiarrhythmics vs. AF ablation?

While AF treatment guidelines recommend either rhythm or rate control as a first line therapy, patients who do not improve on medication are often considered for more invasive treatment such as ablation. However, an increasing number of practitioners are turning to ablation as a first-line therapy, in accordance with the updated 2012 HRS/ EHRA/ ECAS Expert Consensus for Ablation.

The updated consensus states that ablation may be considered prior to initiation of any antiarrhythmic drug therapy.

While this is a separate debate, it is also hotly contested, especially as ablation technology continues to increase, and the procedure becomes more widespread.

Learn more

Register to attend our national meeting to hear all of the latest developments on AF patient treatment.

If your program has leveraged a unique or innovative approach to care for AF patients and you would like to share them with our team, please contact me at macmilln@advisory.com.

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