Overtreatment and undertreatment with anticoagulation in relation to cardioversion of atrial fibrillation (the RHYTHM-AF study).

Antithrombotic therapy is central to the management of atrial fibrillation. This analysis from the RHYTHM-atrial fibrillation (RHYTHM-AF) registry explored the appropriateness of antithrombotic therapy in relation to stroke risk and atrial fibrillation duration in patients with atrial fibrillation. RHYTHM-AF, a prospective multinational registry, enrolled consecutive adult patients with atrial fibrillation considered for cardioversion. We compared the type of antithrombotic therapy administered at the time of cardioversion and at discharge with stroke risk ("high stroke risk" defined by CHA2DS2-VASc >1) and duration of atrial fibrillation (≤48 vs >48 hours or unknown duration). Of 2,972 patients who were cardioverted (34.5% through pharmacologic cardioversion [PCV] and 65.5% through electrical cardioversion [ECV]), 65% were at high risk of stroke and 30% presented with atrial fibrillation of >48-hour or unknown duration. At the time of PCV and ECV, 36% (n = 242) and 84% (n = 1,075) of high-risk patients, respectively, were taking vitamin K antagonists or heparin. At discharge, these rates increased to 62% (n = 414) and 93% (n = 1,191), respectively. Of all low-stroke risk patients with short-duration atrial fibrillation undergoing PCV (n = 260) and ECV (n = 111), 7% (n = 17) and 30% (n = 33), respectively, were taking vitamin K antagonists or heparin at the time of cardioversion. At discharge, these rates increased to 19% (n = 50) and 40% (n = 44), respectively. In conclusion, ECV was frequently performed under appropriate antithrombotic therapy for most high-risk patients with atrial fibrillation, whereas PCV was frequently performed without appropriate antithrombotic therapy. To enhance pericardioversion stroke prevention, cardioversion algorithms should focus less on the type of conversion and more on stroke risk factors and atrial fibrillation duration.

RHYTHM-AF: design of an international registry on cardioversion of atrial fibrillation and characteristics of participating centers.

BACKGROUND: Atrial fibrillation is a serious public health problem posing a considerable burden to not only patients, but the healthcare environment due to high rates of morbidity, mortality, and medical resource utilization. There are limited data on the variation in treatment practice patterns across different countries, healthcare settings and the associated health outcomes. METHODS/DESIGN: RHYTHM-AF was a prospective observational multinational study of management of recent onset atrial fibrillation patients considered for cardioversion designed to collect data on international treatment patterns and short term outcomes related to cardioversion. We present data collected in 10 countries between May 2010 and June 2011. Enrollment was ongoing in Italy and Brazil at the time of data analysis. Data were collected at the time of atrial fibrillation episode in all countries (Australia, Brazil, France, Germany, Italy, Netherlands, Poland, Spain, Sweden, United Kingdom), and cumulative follow-up data were collected at day 60 (±10) in all but Spain. Information on center characteristics, enrollment data, patient demographics, detail of atrial fibrillation episode, medical history, diagnostic procedures, acute treatment of atrial fibrillation, discharge information and the follow-up data on major events and rehospitalizations up to day 60 were collected. DISCUSSION: A total of 3940 patients were enrolled from 175 acute care centers. 70.5% of the centers were either academic (44%) or teaching (26%) hospitals with an overall median capacity of 510 beds. The sites were mostly specialized with anticoagulation clinics (65.9%), heart failure (75.1%) and hypertension clinics (60.1%) available. The RHYTHM-AF registry will provide insight into regional variability of antiarrhythmic and antithrombotic treatment of atrial fibrillation, the appropriateness of such treatments with respect to outcomes, and their cost-efficacy. Observations will help inform strategies to improve cardiovascular outcomes in patients with atrial fibrillation. TRIAL REGISTRATION: Clinical trials NCT01119716.