Relation of initial resting ventricular rate to the ability to achieve and maintain normal sinus rhythm in patients with atrial fibrillation.

Rate-control and rhythm-control strategies in the management of atrial fibrillation (AF) have been shown to have similar effects on morbidity and mortality. Data are lacking as to whether specific electrocardiographic features of AF affect the ability to achieve rate or rhythm control. This study evaluated the relation between initial resting ventricular rate (IRVR) during AF and the subsequent achievement of rate control and rhythm control in the AFFIRM Study. The independent relations between IRVR and the achievement of rate and rhythm control were assessed using multivariate Cox's proportional hazards modeling. In addition, we evaluated whether IRVR was associated with major cardiovascular end points. IRVR was analyzed in 4,059 patients. IRVR was higher in women, smokers, patients who had a first episode of AF, and in patients who had preserved left ventricular systolic function but lower in patients who had coronary artery disease, hypertension, left atrial enlargement, and a qualifying episode of AF that lasted >48 hours. A higher IRVR was independently associated with the achievement (p <0.0001) and maintenance (p = 0.0002) of sinus rhythm, whereas the ability to achieve adequate rate control was independent of IRVR. A higher IRVR was associated with an increased risk of cardiovascular hospitalization (p <0.0001). In the appropriate clinical setting, a rhythm-control strategy should be considered for patients who have a higher IRVR.