Management of atrial fibrillation in patients with structural heart disease.

Atrial fibrillation (AF) is the most common sustained arrhythmia encountered by clinicians. The prevalence of AF increases with age, and the elderly are the fastest growing subset of the population. It has been estimated that there will be 12 million patients with AF in the United States within the next several decades.1,2 AF may present in a wide variety of clinical conditions. The optimal management strategy for an individual patient with AF depends on the patient’s underlying condition. In some patients, AF occurs in the absence of structural heart disease. Clinical trials involving only or predominantly this type of AF may not be completely applicable to those with concomitant heart disorders. Structural heart disease may influence both the approach to management (ie, rate versus rhythm control) and the treatment options available. For instance, fewer antiarrhythmic drugs are available for use in patients with heart failure (HF) as opposed to AF patients who have structurally normal hearts. In addition, some patients with structural heart disease tolerate AF poorly, and the approach to these patients will differ from those with well-tolerated, minimally symptomatic AF. In this article, we will focus on the management of AF in patients with cardiac conditions commonly associated with the dysrhythmia. Several basic principles should be considered when management approaches are planned for any patient with AF (Table 1). First, we should acknowledge that no patient wants to be in AF or does better in AF than in native (ie, untreated), stable sinus rhythm. Therefore, restoration and maintenance of sinus rhythm should be considered for every patient. In addition, a stable rhythm, even if that rhythm is persistent AF, is often better than an unstable rhythm with frequent and abrupt changes that may be highly symptomatic. An argument in favor of stability is suggested by data from the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. A substudy on mechanisms of death showed that the excess mortality associated with the rhythm control strategy in AFFIRM was not due to cardiac causes but rather was attributed largely to noncardiac illnesses.3 It seems possible that other critical illnesses cause changes in the underlying rhythm, which in a vicious cycle further complicate the patient’s problem (Figure 1).4 As shown by Miyasaka and colleagues5,6 in studies from Olmstead County, Minnesota, the first episode of AF may be a time of particular concern because hospitalizations and mortality in the first few months after the first onset of AF are higher than in other periods. These observations lead us to believe that, in most patients, symptoms should be the major determinant behind choices between rhythm and rate control approaches. Stroke is one of the more serious complications of AF. In all patients, stroke risk should be assessed, and the patient’s specific disease state as well as more general risk factors including the CHADS2 or CHA2DS2VASc scores need to be considered.7,8 The patient’s long-term prognosis must also be considered. Decisions made in an 85-year-old individual might well be inappropriate for someone in their 40s and 50s who would face years of treatment.