What is the comparative effectiveness of rhythm control versus rate control treatment strategies when applied to a general population of patients with atrial fibrillation (AF) with longer follow-up?
The investigators used population-based administrative databases from Quebec, Canada, from 1999 to 2007, to select patients 66 years or older hospitalized with an AF diagnosis who did not have AF-related drug prescriptions in the year before the admission, but received a prescription within 7 days of discharge. Patients were followed until death or administrative censoring. Mortality was analyzed by multivariable Cox regression.
Among 26,130 patients followed for a mean (SD) period of 3.1 years (2.3 years), there were 13,237 deaths (49.5%). After adjusting for covariates, the investigators found that the effect of rhythm versus rate control drugs changed over time: after a small increase in mortality for patients treated with rhythm control in the 6 months following treatment initiation (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14), the mortality was similar between the two groups until year 4, but decreased steadily in the rhythm control group after year 5 (HR, 0.89; 95% CI, 0.81-0.96; and HR, 0.77; 95% CI, 0.62-0.95, after 5 and 8 years, respectively).
The authors concluded that rhythm control therapy seems to be superior in the long-term.
This population-based study reports that with increasing follow-up time, the mortality among the patients who newly initiated rhythm control therapy gradually decreased relative to those who initiated rate control drugs, reaching 23% reduction after 8 years of follow-up. Overall, the analysis suggests that the development of antiarrhythmic drugs with fewer adverse effects, but retained or improved efficacy, may result in important gains in the survival of patients with AF. Given the limitations of this observational study, the long-term benefits of rhythm control need to be assessed in prospective randomized studies.
Debabrata Mukherjee, M.D., F.A.C.C. (Disclosure)
Arrhythmias, Afib, Cardiac Rhythm Management, General Cardiology