Sinus rhythm is associated with fewer heart failure symptoms: insights from the AFFIRM trial.

Background: The AFFIRM trial demonstrated no mortality benefit from a rhythm control strategy compared with rate control of atrial fibrillation (AF). However, AF is associated with greater morbidity and mortality and poorer functional status than sinus rhythm, which is more likely to be achieved with a rhythm control strategy.

Objective: This study sought to compare heart failure (HF) symptoms in the different AFFIRM (Atrial Fibrillation Follow-Up Investigation of Rhythm Management) subgroups depending on the prevalence of AF or sinus rhythm throughout the follow-up period.

Methods: This study analyzed a limited-access dataset from the AFFIRM trial, provided by the National Heart, Lung, and Blood Institute.

Results: Symptomatic HF was more common in the rate control than in the rhythm control arm. On analysis based on actual rhythm, New York Heart Association functional status was the best in patients who were in stable sinus rhythm, worse if they were consistently in AF, and much worse if they were changed back and forth between the rhythm control and rate control strategies. Patients in all groups had fewer HF symptoms and required less HF medications when they were in sinus rhythm compared with AF, except for those who crossed over from the rhythm to the rate control strategy.

Conclusions: Patients in the rhythm control arm had fewer HF symptoms than those in the rate control arm. Stable sinus rhythm was associated with the best functional status. Patients who are the most symptomatic in AF but are unable to maintain normal sinus rhythm if treated by the means used in the AFFIRM trial may be candidates for other treatment options, such as ablation.