RATE-AF Trial Boosts Digoxin for Rate Control in Permanent AF
Digoxin now deserves to be considered first-line therapy for long-term heart rate control in older patients with permanent atrial fibrillation and symptoms of heart failure, investigators on a new study conclude.
Dipak Kotecha, MBChB, PhD, MSc, presented the 12-month results of the Rate Control Therapy Evaluation in Permanent Atrial Fibrillation (RATE-AF) trial at the virtual European Society of Cardiology (ESC) Congress 2020.
In the trial, 160 seniors, mean age 76 years, with moderate or severe symptoms due to permanent atrial fibrillation (AF) as well as heart failure symptoms were randomly assigned to low-dose digoxin or the β-blocker bisoprolol, for rate control.
The open-label trial was designed to address a centuries-old unmet need: “Although digoxin has been in use since 1785, we have no longer-term clinical trials of digoxin in patients with AFib or AFib with heart failure,” noted Kotecha, professor of cardiology at the University of Birmingham, United Kingdom.
Not only is digoxin greatly understudied in AF, but permanent AF — the most common form of the arrhythmia — has received only a tiny fraction of the research attention that’s been devoted to paroxysmal or persistent AF, he added.
In RATE-AF, digoxin and bisoprolol proved similarly effective at reducing heart rate, from about 100 beats/min at baseline to the mid-70s at 6 and 12 months. Notably, only a handful of study participants required an additional rate control drug during the 12-month study.
Nor did the two drugs differ in terms of their effect on patient-reported quality of life at 6 months, as reflected by their Short Form-36 (SF-36) Physical Component Score, the primary study endpoint. And both drugs were well tolerated, with 96% of patients in the digoxin group still receiving the drug at a mean of 161 µg/day at 6 months, and 89% still receiving their β-blocker.
But that’s pretty much where the similarities in outcomes ended.
For example, at 12 months, the digoxin group scored significantly higher than the β-blocker group on several domains of the SF-36 Physical Component Score, including vitality, physical function, and global health.
More than half of the digoxin group had a two-class improvement in modified European Heart Rhythm Association AF-related symptoms at 6 months, compared with 10% of the β-blocker group. At 12 months, nearly 70% of the digoxin group had a two-class improvement, vs 30% of patients receiving bisoprolol.
Heart failure symptoms in the digoxin group improved from a mean baseline New York Heart Association (NYHA) class of 2.4 to 1.5 at both 6 and 12 months; the improvement was more modest in the β-blocker group, going from NYHA 2.4 at baseline to 2.0 at both 6 and 12 months.