Prognosis of Atrial Fibrillation in Congestive Heart Failure

To the Editor:

In a recent issue of Circulation, Wang et al¹ report that incident atrial fibrillation in patients with congestive heart failure carries a poor prognosis. They rightfully argue that early intervention to prevent atrial fibrillation in heart failure patients and to prevent congestive heart failure in patients with atrial fibrillation may importantly improve prognosis in patients suffering from one of these conditions. Previously, in a population with advanced heart failure, we did not find a decreased survival associated with incident atrial fibrillation.² This suggests that if patients suffer from advanced heart failure without previous atrial fibrillation, strategies aiming at prevention of the arrhythmia may not benefit any survival.

How to reconcile these facts? In patients surviving until an advanced stage of heart failure without previous atrial fibrillation, the very onset of atrial fibrillation cannot change the lethal effect of heart failure. This view is supported by the present Framingham analysis indicating that previous or concurrent atrial fibrillation in heart failure subjects does not have an impact on prognosis. We feel these are important observations. The advice to initiate antiarrhythmic strategies in heart failure subjects still in sinus rhythm probably only applies to those with mild to moderate forms of the disease. In this respect, the study by Vermes et al,³ in the same issue of Circulation, is promising, because it shows that preventing incident atrial fibrillation is feasible.

Hopefully, the Atrial Fibrillation and Congestive Heart Failure trial⁴ will shed light on the question of which heart failure patients will benefit from primary arrhythmia prophylaxis. Such knowledge may help to avoid needless, inconvenient, and potentially hazardous antiarrhythmic treatment in many patients with heart failure.