Rate Control Efficacy in Permanent Atrial Fibrillation: Successful and Failed Strict Rate Control Against a Background of Lenient Rate Control

Objectives This study sought to investigate differences in outcome between patients treated with successful strict, failed strict, and lenient rate control. Background The RACE II (Rate Control Efficacy in Permanent Atrial Fibrillation) study showed no difference in outcome between lenient and strict rate control in patients with permanent atrial fibrillation (AF). However, in the strict group not all patients achieved the pre-defined heart rate target. Methods The primary outcome was a composite of cardiovascular morbidity and mortality. For the current analysis outcome events were analyzed from end of the dose-adjustment phase until end of follow-up (median 2.9 years [interquartile range: 2.4 to 3.0 years]). Of 614 patients, 608 completed the dose-adjustment phase—301 in the strict (resting heart rate