Atrial Fibrillation Following Investigation of Rhythm Management: AFFIRM Trial Outcomes. What Might Be Their Implications for Arrhythmia Control?

Abstract

During the last decade or so, major changes have been made in the approaches to the control of supraventricular as well as ventricular tachyarrhythmias. A few landmarks need emphasis. A precise understanding of the mechanisms of the origin of cardiac arrhythmias led to the development of electrode catheter ablative techniques; these developments have resulted in an extraordinary high degree of success in curing a very large proportion of patients with re-entrant supraventricular arrhythmias. This striking degree of success, however, has been essentially elusive in the case of ventricular tachyarrhythmias, where the development and refinement of the implantable cardioverter defibrillator has substantially altered the therapeutic landscape of these life-threatening arrhythmias (1).Although they prolong survival in many patients, these important techniques and approaches have not made major inroads in the management of certain arrhythmias and, in particular, atrial fibrillation (2-5). Despite the rapid advances made in understanding how this arrhythmia arises, and how it is propagated and perpetuated (6,7), its treatment remains frustrating and undoubtedly challenging. Furthermore, pharmacologic therapy remains the mainstay of control and prevention of atrial fibrillation (2,3,8). No recent spectacular advances have been made in the synthesis and characterization of novel antiarrhythmic and antifibrillatory compounds (9-15). However, can we learn some lessons from the study of existing drugs and their effects in atrial fibrillation?

Quality of Life and Exercise Performance in Patients in Sinus Rhythm Versus Persistent Atrial Fibrillation

“…Previous reports on QOL in AF Versus SR. Across most QOL domains of the SF-36, patients with persistent or intermittent AF consistently experience a greatly worse QOL compared with that of healthy controls (7)(8)(9)14,20). However, the clinical evidence that conversion and maintenance of SR in patients with AF may predictably result in improvement of QOL continues to be the subject of vigorous debate (21,22). The debate may have stemmed largely from the results of the AFFIRM trial (4).…”

Control of Heart Rate Versus Rhythm in Rheumatic Atrial Fibrillation: A Randomized Study

“…On multiple logistic regression, the only two variables that correlated with successful maintenance of sinus rhythm at 12 months were drug treatment with amiodarone (OR = 2.5; 95% CI, 0.59 to 10.8; P = .013) and QOL score at baseline of 3 or greater (OR = 0.41; 95% CI, 0.18 to 0.92; P = .035). Relatively small clinical studies have indicated that in atrial fibrillation from nonvalvular disease, exercise capacity is increased on the restoration of sinus rhythm (19-21), but this has recently been challenged on the basis of the outcome data from larger controlled clinical trials (12,13), most notably by the AFFIRM trial (13). On the other hand, a recent double-blind placebo-controlled trial in persistent atrial fibrillation has shown that restoration and maintenance of sinus rhythm is associated with an increase in exercise capacity and QOL (22).…”

“…restoration and maintenance of sinus rhythm in patients with atrial fibrillation (11). Symptomatic improvement in the sinus rhythm group has been suggested by the Pharmacological Intervention in Atrial Fibrillation (PIAF) (12) trial, but mortality benefit in the large multicenter Atrial Fibrillation Follow Up Investigation of Rhythm Management (AFFIRM) study (13) has not been confirmed.…”

Amiodarone: A multifaceted antiarrhythmic drug

“…There was no significant impact on mortality but sustained sinus rhythm was associated with significantly improved quality of life as well as exercise performance on standardized treadmill test. Thus, in contrast to the findings in the AFFIRM trial, these overall data are clearly in favor of restoration and maintenance of sinus rhythm in patients with AF in which there is scope for improving exercise capacity, symptoms, and quality of life [32]. A similar conclusions has also been reached in clinical trials that were not as rigorously planned and monitored [ …”