Abstract and Introduction
Abstract
Background All patients with atrial fibrillation (AF) require optimization of their ventricular rate. Factors leading to use of additional rhythm control in clinical practice have not been thoroughly defined.
Methods The ORBIT-AF registry enrolled patients with AF from a broad range of practice settings and collected data on rate versus rhythm control, as indicated by the treating physician. Multivariable logistic regression analysis was performed to identify factors associated with each strategy.
Results Of 10,061 patients enrolled, 6,859 (68%) were managed with rate only control versus 3,202 (32%) with rhythm control. Patients managed with rate control were significantly older and more likely to have hypertension, heart failure, prior stroke, and gastrointestinal bleeds. They also had fewer AF-related symptoms (41% with no symptoms vs 31% for rhythm control). Systemic anticoagulation was prescribed for 5,448 (79%) rate-control patients versus 2,219 (69%) rhythm-control patients (P < .0001). After multivariable adjustment, patients with higher symptom scores (severe symptoms vs. none, OR 1.62, 95% CI 1.41–1.87) and those referred to electrophysiologists (OR 1.64, 95% CI 1.45–1.85) were more likely to be managed with a rhythm control strategy.
Conclusions In this outpatient registry of US clinical practice, the majority of patients with AF were managed with rate control alone. Patients with more symptoms and who were treated by an electrophysiologist were more likely to receive rhythm-control therapies. A significant proportion of AF patients, regardless of treatment strategy, were not treated with anticoagulation for thromboembolism prophylaxis.
Introduction
Atrial fibrillation (AF) represents the most common dysrhythmia in the United States, and contributes significantly to healthcare expenditures. Management of AF varies and may include medical and interventional therapies to maintain sinus rhythm ("rhythm control"), as well as strategies to control the ventricular rate. While many patients managed with rhythm control also receive medications to control ventricular rate, there is a significant percentage of patients managed only with rate-controlling therapies (hereafter referred to as "rate control"). Clinical trials in selected patients have failed to demonstrate a survival benefit or lower complications with a rhythm control strategy, yet contemporary observational data suggest a long-term benefit. These discrepant findings may be related to clinical features that determine selection of management strategy in practice, such as symptomatology, quality of life, and other patient or provider preferences. The appropriate criteria for selecting a management strategy in patients with AF have not been well-defined; therefore, it is largely left to providers to determine which patients are suitable for rhythm versus rate control alone.
To date, the use of rhythm versus rate control strategies has not been well-characterized in US community practice. International data, as well as the AFFECTS registry in the United States, have suggested significant differences in the population of patients selected for rate versus rhythm control, as well as differences in outcomes across a broad spectrum of AF patient types. Furthermore, contemporary medical therapy for both rate control and stroke prevention across management strategies remains unclear. We used data from the ORBIT-AF registry to address the following aims: (1) to measure the rates of use of different management strategies in AF patients in the United States; (2) to identify factors associated with the selection of a rhythm control strategy, versus rate control only; and (3) to describe the medical management of patients with rhythm versus rate control, including antiarrhythmic and anticoagulant therapies.