Mustafa I Ahmed1; Marjan Mujib1; Olaniyi J Ekundayo1; Linda Jones1; Bo Liu1; Michel White2; Wilbert Aronow3; Ali Ahmed4
　　1 Univ of Alabama at Birmingham， Birmingham， AL
　　2 Montreal Heart Institute， Montreal， Canada
　　3 New York Med College， Valhalla， NY
　　4 Univ of Alabama at Birmingham， Birmingham， AL
　　Background: The prevalence of atrial fibrillation (AF) increases substantially after age 70 years， an age group， who are also at risk for adverse events from rhythm-control drugs. We used the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) data to test the hypothesis that rate (v. rhythm) control is associated with reduced mortality in AF patients 70 years.
　　Methods: Of the 4060 AFFIRM patients with recurrent AF and without contraindication to anticoagulation， who were randomized to rate or rhythm control groups， 2248 were 70 years. Propensity scores for rate control， calculated for each patient， were used to assemble a cohort of 941 pairs of patients 70 years who were balanced on 55 baseline covariates. Matched Cox regression models were used to estimate the effect of rate control during 3.4 years of mean follow-up.
　　Results: All-cause mortality occurred in 19% (rate， 548/10000 person-years) and 23% (rate， 675/10000 person-years) of matched rate and rhythm control patients resp. (matched hazard ratio {HR} when rate was compared with rhythm， 0.75; 95% CI， 0.59 – 0.94; P=0.014; Figure). All-cause hospitalization occurred in 62% and 69% of matched rate and rhythm control patients resp. (matched HR associated with rate control， 0.86; 95% CI， 0.72–1.01; P=0.068). Pre-match (n=2248) unadjusted， multivariable-adjusted， and propensity-adjusted HR (95% CI) for all-cause mortality associated with rate control were 0.82 (0.69 – 0.99; P=0.039)， 0.77 (0.64 – 0.93; P=0.008)， and 0.83 (0.69 –1.00; P=0.048) respectively.
　　Conclusion: Compared to a rhythm control strategy， a rate control strategy is associated with reduction in death in elderly patients with AF.
　　Figure. Kaplan-Meier plots for all-cause mortality by treatment strategy