Why We AFFIRM Rate Control for A-fib

On the Shoulders of Giants

I've got rhythm...
Should we chemically or electrically cardiovert a-fib back to normal sinus rhythm (NSR), or should we just control the ventricular rate?  In this large randomized study, there was no 5-year mortality advantage of rhythm control over simple rate control.  They were statistically the same, though the trend favored rate control.  Some would argue that hearts are happier in NSR.  A recent study from Canada shows that early cardioversion is safe and feasible in new onset a-fib (within 48 hours), but this is not the patient population studied here.  AFFIRM was only older people with existing non-valvular a-fib that were at high risk for a bad outcome.

Spoon Feed
Rhythm control for chronic a-fib had no advantage over rate control.  See the AHA guidelines on a-fib or take a deep dive into AFFIRM.


Abstract

N Engl J Med. 2002 Dec 5;347(23):1825-33.

A comparison of rate control and rhythm control in patients with atrial fibrillation.

Wyse DG1, Waldo AL, DiMarco JP, Domanski MJ, Rosenberg Y, Schron EB, Kellen JC, Greene HL, Mickel MC, Dalquist JE, Corley SD; Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) Investigators.

Author information:

1AFFIRM Clinical Trial Center, Axio Research, 2601 4th Ave., Ste. 200, Seattle, WA 98121, USA.

Comment in

Abstract

BACKGROUND:

There are two approaches to the treatment of atrial fibrillation: one is cardioversion and treatment with antiarrhythmic drugs to maintain sinus rhythm, and the other is the use of rate-controlling drugs, allowing atrial fibrillation to persist. In both approaches, the use of anticoagulant drugs is recommended.

METHODS:

We conducted a randomized, multicenter comparison of these two treatment strategies in patients with atrial fibrillation and a high risk of stroke or death. The primary end point was overall mortality.

RESULTS:

A total of 4060 patients (mean [+/-SD] age, 69.7+/-9.0 years) were enrolled in the study; 70.8 percent had a history of hypertension, and 38.2 percent had coronary artery disease. Of the 3311 patients with echocardiograms, the left atrium was enlarged in 64.7 percent and left ventricular function was depressed in 26.0 percent. There were 356 deaths among the patients assigned to rhythm-control therapy and 310 deaths among those assigned to rate-control therapy (mortality at five years, 23.8 percent and 21.3 percent, respectively; hazard ratio, 1.15 [95 percent confidence interval, 0.99 to 1.34]; P=0.08). More patients in the rhythm-control group than in the rate-control group were hospitalized, and there were more adverse drug effects in the rhythm-control group as well. In both groups, the majority of strokes occurred after warfarin had been stopped or when the international normalized ratio was subtherapeutic.

CONCLUSIONS:

Management of atrial fibrillation with the rhythm-control strategy offers no survival advantage over the rate-control strategy, and there are potential advantages, such as a lower risk of adverse drug effects, with the rate-control strategy. Anticoagulation should be continued in this group of high-risk patients.

Copyright 2002 Massachusetts Medical Society

PMID: 12466506 [PubMed - indexed for MEDLINE]