Comparative effectiveness of rhythm control vs rate control drug treatment effect on mortality in patients with...

Controversy continues concerning the choice of rhythm control vs rate control treatment strategies for atrial fibrillation (AF). A recent clinical trial showed no difference in 5-year mortality between the 2 treatments. We aimed to determine whether the 2 strategies have similar effectiveness when applied to a general population of patients with AF with longer follow-up.

We 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, we found that the effect of rhythm vs 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% CI, 1.01-1.14), the mortality was similar between the 2 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).

In this population-based sample of patients with AF, we found little difference in mortality within 4 years of treatment initiation between patients with AF initiating rhythm control therapy vs those initiating rate control therapy. However, rhythm control therapy seems to be superior in the long-term.