Study on Rhythm Control Therapy in Atrial Fibrillation Patients

Approximately 30% of patients with atrial fibrillation are known to have heart failure. Risk of cardiovascular complications, including all-cause and cardiovascular death, stroke, etc., requires careful cardiac management.

Rhythm control therapy was found to be most beneficial when initiated within a year of diagnosing atrial fibrillation in patients with heart failure, reveals a new study by Andreas Rillig and team. This study has been published in the Circulation journal.

The objective of the study was to evaluate the effects of Rhythm control therapy in atrial fibrillation patients after a year of diagnosis.

The study was a prespecified subanalysis of the randomized EAST-AFNET4 trial (Early Treatment of Atrial Fibrillation for Stroke Prevention Trial) which assessed the effect of systematic, early rhythm control therapy (ERC; using antiarrhythmic drugs or catheter ablation) compared with usual care (allowing rhythm control therapy to improve symptoms) on the two primary outcomes of the trial and on selected secondary outcomes in patients with heart failure, defined as heart failure symptoms New York Heart Association II to III or left ventricular ejection fraction [LVEF] <50%.

Results of the Study

• A total of 798 patients (300 [37.6%] female, median age 71.0 [64.0, 76.0] years, 785 with known LVEF). The majority of patients (n=442) had heart failure and preserved LVEF (LVEF≥50%; mean LVEF 61±6.3%), the others had heart failure with midrange ejection fraction (n=211; LVEF 40%–49%; mean LVEF 44 ± 2.9%) or heart failure with reduced ejection fraction (n=132; LVEF<40%; mean LVEF 31±5.5%).
• The primary safety outcome (death, stroke, or serious adverse events related to rhythm control therapy) occurred in 71 of 396 (17.9%) patients with heart failure randomly assigned to ERC and in 87 of 402 (21.6%).
• Worsening of heart failure or acute coronary syndrome occurred less often in patients randomly assigned to ERC (94/396; 5.7 per 100 patient-years) compared with patients randomly assigned to usual care (130/402; 7.9 per 100 patient-years; hazard ratio, 0.74 [0.56–0.97]; P=0.03), not altered by heart failure status (interaction P value=0.63).
• Patients with heart failure were randomly assigned to usual care (hazard ratio, 0.85 [0.62–1.17]; P=0.33). LVEF improved in both groups (LVEF change at 2 years: ERC 5.3±11.6%, usual care 4.9±11.6%, P=0.43).
• ERC also improved the composite outcome of death or hospitalization for worsening of heart failure.

Rillig and team concluded that "Rhythm control therapy conveys clinical benefit when initiated within 1 year of diagnosing atrial fibrillation in patients with signs or symptoms of heart failure."

For further information: https://doi.org/10.1161/CIRCULATIONAHA.121.056323