Pursuit of Sinus Rhythm in Patients with Atrial Fibrillation: Is the Effort Worth It?

the arrhythmia that is the most frequent disorder of cardiac rhythm for which patients are hospitalized in the United States (1). Over the next 50 years, the incidence of AF in the United States population is likely to reach nearly 6 million (2). AF is undoubtedly the arrhythmia of the aging population (3,4). Once considered a benign rhythm disorder, it is now known to be associated with a number of potentially serious consequences such as embolic stroke, heart failure, and death (3). Over many decades, two diametrically different approaches have evolved in the management of AF. Until recently, central to the initial approach was the restoration and maintenance of sinus rhythm for most and ideally all cases of the arrhythmia presenting for the first time. Only in those patients with AF in whom sinus rhythm could not be restored and maintained did anticoagulation combined with ventricular rate control come to be considered the optimal therapy. It has also been the prevalent belief that restoration and maintenance of sinus rhythm prevented the development of embolic stroke and thus anticoagulation could safely be discontinued. However, many physicians believed that in a patient with recurrent or persistent AF, anticoagulation should be continued despite the maintenance of sinus rhythm if the risk factors for the arrhythmia could not be eliminated permanently. In support of this approach, perhaps the most compelling reason has been that it is almost impossible to ensure that sinus rhythm can be maintained continuously in every patient restored to sinus rhythm. During the last decade, a number of developments in the management of AF have had a reasonably direct bearing on the current approaches. For example, the outcome data from blinded and placebo-controlled clinical trials in AF have clearly established that appropriately managed anticoagulation with warfarin prevents stroke in approximately 70% of patients and lowers mortality by 26% (5). This has led to the widespread use of anticoagulants in most patients with paroxysmal as well as persistent AF (3,5), especially in patients with AF in the setting of structural heart disease and other risk factors as well as in patients after the age of 62 to 65 years, with or without risk factors. It has become evident that in these subsets of patients, irrespective of sinus rhythm or AF, anticoagulation should be prescribed unless there is a major contraindication. It is likely that much larger numbers of such patients may be anticoagulated if less cumbersome oral anticoagulants become available. From large epidemiologic studies, it has been known for many years that a 1.5-fold to 1.9-fold increase in annual mortality is associated with AF compared with sinus rhythm, suggesting that restoration and maintenance of sinus rhythm may make favorable inroads into these mortality figures (6). This was the primary objective of the National Institutes of Health-supported Atrial Fibrillation Following Investigation of Rhythm Management (AFFIRM) trial (7), the largest AF mortality trial, in which 4060 patients with paroxysmal (predominant), chronic, or persistent AF were randomized to sinus rhythm versus rate-control treatment limbs in an open-label fashion. The results of the trial are now well known and widely publicized and are already having a significant impact on the clinical management of patients with Editorial