ArticlesRhythm or rate control in atrial fibrillation—Pharmacological Intervention in Atrial Fibrillation (PIAF): a randomised trial
Introduction
Atrial fibrillation is the most commonly encountered sustained clinical arrhythmia with an incidence that increases twofold with every decade after 55 years of age.1 Partly because populations in industrial countries are ageing, atrial fibrillation has become the most frequent principal diagnosis of cardiac rhythm disturbance at hospital discharge.2 In addition to atrial-fibrillation-induced symptoms and impairment of quality of life, the arrhythmia is associated with serious complications such as systemic embolism, haemodynamic dysfunction, and tachycardia-mediated cardiomyopathy.3 In many institutions, the main therapeutic goal is restoration and maintenance of sinus rhythm. Heart-rate control is usually only pursued when rhythm control fails. With electrical cardioversion, sinus rhythm can be re-established in many patients,4, 5 although maintenance of sinus rhythm is not assured thereafter. In fact, sinus rhythm can be maintained at 1 year in only about 30% of patients who receive placebo.3 Accordingly, preventive antiarrhythmic therapy is often mandatory. Increasing recognition of the hazards of antiarrhythmic therapy, particularly proarrhythmia6, 7 used to maintain sinus rhythm, has led to serious reconsideration of this treatment strategy.8 As a consequence, control of ventricular rate with persistent atrial fibrillation has been proposed as an alternative strategy. At present, however, no data from prospective trials are available to answer the question whether rate control or rhythm control in atrial fibrillation is superior. The Pharmacological Intervention in Atrial Fibrillation (PIAF) trial is a randomised trial to examine this important clinical issue.
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Study design
PIAF was designed as an open, randomised pilot study to compare two different treatment strategies in patients with persistent and symptomatic atrial fibrillation.9 Participating patients were randomly assigned (randomisation codes generated per centre, allocation of patients in blocks of six) to one of the two following treatment arms. In group-A patients, no attempts were made to terminate atrial fibrillation. The therapeutic goal was to achieve an improvement in symptoms by controlling
Characteristics of patients
252 patients were included in PIAF, 125 patients randomised to group A and 127 to group B (table 1, figure 1). At baseline, 87 (70%) group-A patients and 92 (72%) group-B patients were receiving digoxin. Angiotensin-converting-enzyme inhibitors were given in 46% and 44% of patients, β-blockers in 9% and 10%, both respectively. No patient received class I or III antiarrhythmic drugs. During follow-up, two patients in each group died. In group A, one patient died due to intractable heart failure
Discussion
PIAF is the first randomised multicentre trial to compare two different therapeutic strategies, rate versus rhythm control, in patients with symptomatic atrial fibrillation. The results indicate that neither of the two therapeutic strategies is superior in terms of improvement in atrial-fibrillation-related symptoms. The results may have important implications for the care of individual patients who are treated mainly for symptomatic reasons in most cases.
For many years, rhythm control has been
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